Tim Noakes on carbohydrates

This entry is part 1 of 29 in the series Noakes

Originally published in the Daily Maverick.

In one of my first columns on Daily Maverick, Michael Pollan and his food rules (“the whiter the bread, the sooner you will be dead”) were used to illustrate the modern obsession with eating “healthy” food, or orthorexia. Pollan is an example of a celebrity nutritionist, who – while not necessarily offering harmful advice – could be accused of simplifying things to such an extent that what starts as sound advice mostly ends up being accepted on faith or as dogma.

Recently, South Africa’s sports-science guru Tim Noakes has been receiving plenty of media coverage following his about-turn on matters dietary. Many of you will recall Noakes as an advocate of carbo-loading, especially for athletes. But even those of us who aspired to complete a 10km shuffle had little to fear from the carbohydrate. Until now, where for many of us our fondness for carbohydrates “is an addiction that is at least as powerful as those associated with cigarette consumption and some recreational drugs like heroin”.

In general it’s a good thing to see scientists change their minds, because it’s evidence of the scientific method at work. When the evidence changes, so should our views. But such is the current fear of food, manifested in daily articles about epidemics of obesity and the various ways we’re killing ourselves through what we eat, that it’s sometimes a little easy to join the next dietary fashion without thinking enough about whether we’re convinced by the evidence rather than by the hysteria.

A form of cultural amnesia is apparent in most dietary programmes – they spawn books and instructional DVD’s, but are quite often simple revisions of advice we’ve heard before, packaged under a different name with a different guru’s face on the cover. But if the advice is good and presented in a way that doesn’t encourage mindless obedience, us non-specialists could certainly benefit from knowing about what – in this instance at least – appears to be somewhat of a breakthrough moment for dietary knowledge.

The breakthrough is not Noakes’s and he’s the first to admit that, citing William Harvey and William Banting, and more recently Robert Atkins and Gary Taubes as those who introduced him to the concept that most of us would apparently lose weight and live healthier lives on low-carbohydrate diets. I say “apparently” not only because I haven’t tried it myself, but also because the evidence for Noakes’s claim doesn’t seem nearly as convincing as he’d like us to believe.

While some philosophers of science (like Nancy Cartwright [pdf], for one) disagree, the gold-standard in science is generally held to be the RCT, or randomised controlled trial. In an RCT, subjects are randomly allocated to receive one or another of the different drugs or interventions being tested, and those subjects are then treated differently only in respect of differences that are intrinsic to the different treatments under comparison.

In the case of an RCT evaluating different diets, you’d therefore want to ensure that you control for factors like how much exercise subjects in each cohort do, and your randomised selection of subjects into those cohorts should have ensured a balance between other factors that could influence the outcome of the treatments being compared (whether you know about those factors or not).

For diet – and specifically, comparing diets with varying proportions of carbohydrates – two recent RCT’s are relevant here. In 2009, The New England Journal of Medicine (360,9) published a study by Frank Sacks (pdf) and others, in which four diets were tested on 811 overweight adults. The subjects were randomly assigned to one of four diets, where “the targeted percentages of energy derived from fat, protein, and carbohydrates in the four diets were 20, 15, and 65%; 20, 25, and 55%; 40, 15, and 45%; and 40, 25, and 35%”. The subjects were then monitored for two years to determine the short- and longer-term effect of these four diets.

Their results? “Any type of diet, when taught for the purpose of weight loss with enthusiasm and persistence, can be effective.” To put it more simply, “reduced-calorie diets result in clinically meaningful weight loss regardless of which macronutrients they emphasize”. So, if Sacks and his research collaborators are to be believed, eating less is the important thing rather than what you eat – at least when it comes to weight-loss.

Russell de Souza’s research (published this year in The American Journal of Clinical Nutrition) involved 424 subjects randomly allocated to diets involving 25% or 15% protein; 40% or 20% fat; and 65% or 35% carbohydrates. Again, the authors note that the subjects “lost more fat than lean mass after consumption of all diets, with no differences in changes in body composition, abdominal fat, or hepatic fat between assigned macronutrient amounts”.

Of course, Noakes might be different, and he’d know as well as anyone that a diet that works for one person might not work for all. He in fact claims that he is different (and suggests that many of us might be) in being “carbohydrate resistant”, which brings with it a predisposition to developing adult-onset diabetes. And again, this might be true – but we haven’t yet seen an RCT which compares the effects of various diets on only people who are carbohydrate resistant.

It therefore seems premature – even unjustified – to speak of this diet in such unequivocally positive terms, not to mention introducing the language of moral panics in the form of our hypothetical “addiction” to carbohydrates. As Ben Goldacre (and others, I’m sure) have pointed out, anecdotes are not data, and the bulk of the data available right now suggest that the main problem is simply that we eat too darn much.

Speaking of which, another concern with diets such as this presents itself. Much as you’ll usually find anti-vaccination idiocy represented in the middle-class but rarely by the poor, a diet like this seems quite out of reach to anyone struggling to find money to feed themselves and their families. We’re told to avoid bread, rice, pasta and potatoes in favour of eggs, fish, meat, dairy products and nuts (only some nuts – peanuts and cashews, among others, are evil nuts).

So, above and beyond wondering whether the Noakes diet is evidentially justified, rather than being yet another example of a celebrity-led fad, it’s also somewhat discomfiting on a political level. The increasingly obese poor might after all end up inheriting the earth, simply because there’s no space left on it for anyone else.

See the Daily Maverick link at the top for a range of comments on this column. One particularly worth highlighting, and pasted below, is a response from Prof. Noakes.

Jacques,

By focusing on the evidence or lack thereof that a low carbohydrate diet is an effective means of losing weight you miss a couple of important points. These points are more fully described in the most recent edition of my book, Challenging Beliefs. First, my personal interest in the low carbohydrate diet relates to my predisposition to develop diabetes; my substantial weight loss on this eating plan is an unexpected bonus but it is not the reason why I have committed to this eating plan. The scientific evidence is absolutely clear – it is the persistent consumption of a high carbohydrate diet by person like myself with a genetic predisposition to develop diabetes because we are carbohydrate-resistant that ultimately causes us to develop that disease. The prevention and correct treatment of the condition is also blindingly obvious and proven in the literature – it is a diet that restricts the total carbohydrate intake to as few grams a day as possible, preferably less than about 50 grams per day. Yet sadly this is not the advice that predisposed people like myself or indeed those who already have the disease are likely to receive. I wish someone had told me this 20 years ago. I do not want others not to know this information if it can save them from the disastrous consequences of this awful disease.

Thus my interest in publicizing this eating plan is not to be just another “celebrity fad diet”.

Second, for 33 years I ate the so-called heart healthy, low fat, high carbohydrate “prudent” diet – the same diet that did not prevent the development of all the complications of diabetes in my father. Yet in retrospect, all that diet did for me was to make me fat, lazy, increasingly closer to developing full blown diabetes whilst all the time destroying my running ability. When I finally discovered that these unpleasant symptoms were not caused by aging but by my high carbohydrate “healthy” diet, I was naturally somewhat surprised. Thus in advocating this alternate eating plan, I have been careful to stress that the key benefit is a dramatic increase in the quality of life – something that the scientists have not measured. So I am now able again to run as I did 20 years ago and for me this is very important. I also have a level of energy that I remember having 40 years ago. In addition I have delayed the progress of my pre-diabetes. Those are the benefits that I have enjoyed by restricting my carbohydrate intake. Whatismore, daily I receive a wad of emails from grateful South Africans indicating how much better they feel and how their quality of life and often their sporting performances have improved simply by reducing their carbohydrate intakes as have I. So you see, it is not just about weight loss.

Third you glibly say that “we simply eat too much”. I agree – but why? Lions don’t eat too much; nor do any other free-living mammal that I know (other than our cats and dogs whose health is unfortunately also being undermined by the provision of a so-called “science diets” that forces these carnivores to eat high carbohydrate diets – diets for which their evolution has not prepared them). Why is it then that lions know exactly how much too eat so that they do not become fat and lethargic and unable to hunt? Could it be because they have a perfect appetite control – something that humans have always had but have suddenly lost in the past 30-40 years as the global diabetes and obesity epidemic has increased exponentially?

You see what I have learned, as confirmed by all those who successfully adapt to this low carbohydrate eating plan, is that we rapidly lose our hunger and feel satiated all the time (since fat and protein satiate whereas carbohydrates drive hunger in many people). No longer do we spend our days hunting for addictive high carbohydrate meals that fail to satisfy hunger for more than a few hours. As a result we reduce our energy intakes by at least a third without ever feeling hungry. So we lose weight and return our body masses into the safe and healthy range without any effort. Nor do we need to exercise to maintain that weight loss (although because we now again have the energy we enjoyed at a younger age, we also become more active). The reality is that for many of us the only way to bring our appetites under control is completely to avoid carbohydrates and to return to our former evolutionary state as predatory carnivores.

Also not considered in your analysis are the health benefits of simply eating less – there is a large body of evidence showing that eating less increases life expectancy in a range of mammals. Thus eating too much of anything carries health consequences with it.

So as you personally assess whether or not you should be eating fewer or more carbohydrates, you can see that it is not simply a question of whether or not you want to lose weight. It is about quality of life and for how long you want to live. If those issues are important to you then you need to question whether or not you can improve what you eat, perhaps by eating a diet that is not as full of carbohydrates.

But if these issues are of no consequence to you – if you personally are happy to spend your life “shuffling through a 10km” – then be my guest. But don’t condemn your readers to what nearly happened to me simply because you failed to research the topic as exhaustively as this complex topic requires.

Timothy Noakes

 

Lessons in bad science – Tim Noakes and the SAMJ

This entry is part 2 of 29 in the series Noakes

As I’ve said before, Professor Tim Noakes might well be right in his advocacy for a low carb, high fat diet. Whether he is right or wrong is however – to some extent, at least – a separate issue from whether he’s providing an example of sound scientific reasoning in reaching the conclusions he does.

It’s understandable that people outside of science, academia, or any overtly evidence-based work might confuse personal experience, anecdotes and badly drawn samples for good evidence. However, the principles of scientific reasoning (even as taught to first-year students, as I’ve done for years), remind us of these and other common errors. Once you know about confirmation bias, you shouldn’t flaunt the fact that you deploy it, but rather regret that you (like everyone) are prone to quite typical errors.

As a practitioner of evidence-based something-or-other, you’d know and understand counter-intuitive things, for example that a conclusion can sometimes be the correct one, regardless of how poor the argument for that conclusion is. And, that a good argument can sometimes result in a false conclusion.

Most important, perhaps, is that you’d know of the various resources we have for making it more likely that we reach the correct conclusion, and you’d know of the sorts of errors to avoid because they tend to lead us to false conclusions. And given that you care most of all for getting closer to the truth of the matter, you’d be aware of your responsibilities to set an example to others of sound reasoning about science – especially if you are perceived to be an authority figure.

When a scientist like Noakes seems willing to ignore most of these principles in favour of promoting a conclusion – through whatever support comes along – he doesn’t sound passionate, committed, maverick and so forth. He sounds like a quack (and sometimes, even a conspiracy theorist, at least when citing some of the reasons why his “obvious” (to him) truths are somehow not adopted by everyone). To Noakes, all research that disagrees with him is “industry-funded” or otherwise tainted, but never treated as counter-evidence.

Among those that Noakes has quoted in support of either his view or his approach to science are the evolution-denier and proponent of scientific racism that is Louis Agassiz, and the anti-vaccine Weston Price Foundation. He’ll tweet links to pieces arguing that carbohydrates might have played a role in the Newtown shootings. And when challenged on whether his approach is sound, he says things like this:

Worst of all, he doesn’t seem to really understand what the stakes are, even as he speaks of a decades-old diet lie that is apparently killing us all. He’s embraced the false dichotomy that we have a choice between the “orthodox” dietary advice (that is harming us) and his model (that will make us thin, cure diabetes and so forth). On his model, choosing option B (his model) has no risks, even though we have no long-term data regarding the possible harmful consequences of a high-fat diet.

This doesn’t mean people won’t be persuaded by Noakes. They will be and are being persuaded in their droves, thanks partly to positive short-term results on the diet, and also to some very engaged PR on Twitter, radio, magazines and television. But they’re also being persuaded because – like most people – they are prone to overstating the value of anecdotes in supporting a conclusion.

The fact that they are persuaded is not, however, further evidence for your conclusion.

Yet, according to Noakes, perhaps it is. And sadly, South Africa’s flagship medical journal, the SAMJ, has published a Noakes paper that is a textbook example of bad science in this and other ways. Somehow, this paper got through peer-review, but I can pretty much guarantee you that if we did a Sokal-type experiment, submitting this under fictitious names, it would never get published. It’s solely on the basis of the authority of the “name” of an acclaimed scientist that it was published as a study, rather than on the letters pages or somewhere less notable.

Here’s the 140-character summary of why this shouldn’t have been published as a study, or made it through peer review:

Basically, the “study” is confirmation bias run amok. If I were a UFO conspiracy theorist, and led a society dedicated to discussing our abduction experiences, the letters I might receive from prospective members might appear to me to be further evidence that UFOs exist. But I’d be wrong. They’re not, because my letter-writing audience are self-selected (we can predict, in advance, that they are likely to share my conclusion) and unreliable (they are offering anecdotes, and we have no idea how reliable their testimony is).

People who try the “Noakes diet” to no effect will not write letters to him saying so. And as for those who do write, we have no knowledge (or control) over any other factors relevant to their weight-loss experiences. It’s plausible that someone trying a new diet will, for example, also be motivated to exercise more – but we can’t control for that.

In response to these and other criticisms on Twitter, Noakes asked his critics why we were focusing on the anecdotes, rather than the controlled trials that agreed with the anecdotes. But this again misses the point – one wouldn’t need the anecdotes to make the case if the data did so already. To include the anecdotes means that you see them as adding some value, and you shouldn’t do so.

It’s not everyone else’s job to defeat your anecdotal evidence (that should never even be presented). It’s your job to gather non-anecdotal evidence. And if you don’t have that as yet, it’s not someone else’s responsibility to get it for you, as in comments like

(This, because of another elementary principle of scientific reasoning, namely the burden of proof.)

To wrap this up: I agree that a trial is needed. But there’s a different issue at stake also, and this is that Noakes is encouraging incompetent and pseudoscientific thinking on matters of science, and encouraging a cultish adherence to a model that hasn’t yet been scrutinised in full, and for which we have no long-term data. This is irresponsible, and an abrogation of his responsibility as a scientist and an educator.

But these are no doubt all irrelevances to Noakes, even perhaps evidence of bias or conspiracy. After all, at the end of the day, the ultimate evidence is remarkably elegant: the thinnest person in the argument wins, and obese people can’t be right.

P.S. Prof Noakes has left a substantial comment below. Unfortunately, it does his cause absolutely no good, as I explain in this follow-up post.

More lessons in bad science (and reasoning) from Noakes

This entry is part 3 of 29 in the series Noakes

In case you missed it, there’s a 1400 word comment from Prof. Tim Noakes on my previous blog post. Seeing as the bulk of his comment is entirely unrelated to the subject of that blog post, I thought it offered a handy opportunity to provide an additional example of reasoning gone wrong, this time both in basic logic, and again in science. (Also, I’d need another 800 or so words to match his word-count.) So, below you’ll find block-quotes of his full comment, and an explanation of the errors committed. If you want to see his quote in context, please visit the original piece, Lessons in bad science – Tim Noakes and the SAMJ.

Apologies, but this will be somewhat lengthy. I’ll try to keep each unit of quote and response comprehensible on its own, though. Those of you who get bored, please do scroll down and read the bit headed (in bold) “A very important bit” before you leave.

And a reminder – my post the other day wasn’t about the diet itself. This post isn’t about the diet either. It would be fantastic if Noakes/Taubes and the rest were correct in this instance, in that they would have re-discovered or popularised a highly cost-effective way to treat an a highly significant public health problem. Or, various problems, including obesity and diabetes. That would be something to be celebrated, and I’ll be one of those celebrating.

However, if we can arrive at that outcome while supporting (and reinforcing) the scientific method and basic logic, surely that’s an even better outcome?

Noakes begins by re-stating a powerful anecdote:

What is really so funny is that this is a report of how 127 people felt their lives had been dramatically improved by following a particular diet. Included were 14 who claimed they had been “cured” of Type 2 diabetes – confirmed in 3 cases I investigated further. To my knowledge the SAMJ has never before carried a report in which patients with an “incurable” condition (type 2 diabetes) were cured of that condition. One doctor who had told his wife he would be dead in 7 years because he had 5 “incurable” conditions, was completely healed of all conditions (no more medications required) when he restricted his carbohydrate intake.

Everything else he had ever tried (according to his conventional medical training) including treatment by the best medical specialists in Cape Town had done little for his health. Naturally this medical practitioner who had never in 57 years been exposed to this information (why not?), concluded that the dietary advice I gave him had produced a “miracle”. He now includes this method in his treatment options for his patients with obesity/diabetes/metabolic syndrome. He now informs me at least monthly of how much success he is having with this dietary treatment for these patients.

After the words “felt”, “claimed” and then the quotation marks around “cured” in the first two sentences, the thing you’ll note about this anecdote is that it uses language that is entirely inappropriate to the level of evidence available. Imagine yourself to be someone who has Type 2 diabetes, or who is overweight, and who then reads the two paragraphs above. If your level of scientific literacy was that of the average person, you’d come away thinking that there’s something akin to certainty that this diet is effective.

If you’re a marketer, this tactic is completely understandable, and appropriate. But science should be a domain of reason and evidence, not of hyperbole, and not of presenting contested evidence as if it obviously demonstrates something that it is not known to demonstrate. Second, as I’ve said in my original piece, if the evidence exists, you wouldn’t need the anecdotes. Unless, of course, Noakes has so little confidence in the acumen of his peers that he thinks that they would be equally persuaded by either.

Paragraph two contains the quite typical injection of conspiracy theory, with its suggestion that something must be afoot for this medical practitioner to not have heard this dietary advice before. And yes, it’s possible that something was and is afoot – that there is a systematic bias against this approach to diet. If so, that’s a problem that should be remedied. But it has no bearing on whether the advice is in fact good or bad advice. It can have a bearing on how much evidence we have, in that research might have been stymied or inappropriately directed. (Noakes, however, keeps insisting that the evidence is clear, so it seems that this problem is surmountable.)

I wrote the article to alert my colleagues to the fact that there is a simple dietary option that might be able to reverse the very conditions that our profession finds so difficult to treat – obesity, type 2 diabetes, metabolic syndrome. I also referred to the extensive scientific literature showing why and how this dietary intervention does and should work for people with these conditions. The explanations are simple, obvious and proven.

But then perhaps you need a training in the medical sciences to understand those mechanisms, Without some understanding of biochemistry, it is not possible to follow that argument. What one cannot understand, one naturally dismisses as irrelevant.

As I’ve asked before, if the “extensive scientific literature” makes the case, why do we need the anecdotes? As above, the use of the word “proven” massively overstates the case, and again indicates a failure to understand why he comes across as pseudoscientific in these regards. If it were “proven”, there would be far less disagreement in the medical profession than there seems to be about this sort of diet’s efficacy.

In general, though, to quote from a comment I made on the previous post, “the issue is that if non-anecdotal evidence for the same conclusion exists (as he asserts), that evidence would be sufficient by itself. So, either it doesn’t exist, and he needs to rely on the anecdotal evidence (which teaches a bad lesson regarding scientific reasoning), or it does exist, but he thinks that the anecdotal evidence adds weight to the conclusion (which it doesn’t, as he should know)”.

The last paragraph contains another fairly typical tactic for Noakes, namely an attempt to discredit an opponent through focusing on something irrelevant or personal, as we saw in the “fat-shaming” comment in the previous post. Because there are two possibilities here: first, that he’s right that we need medical training to understand this. If so, I’m mystified as to why Noakes does all this public speaking to laypeople, and also that he writes on these matters in (almost exclusively) lay publications and books as much as he does, seeing as he knows none of those audience-members can understand what he’s saying.

Alternatively, he’s subtly suggesting I’m too thick to “get it”. But again, seeing as my post was not about the diet, but about what evidence and arguments look like, I’d have to protest and tell him that I “get that” very well, and that of all the medical practitioners who have commented or Tweeted about the post in question, everyone except Noakes thinks I’m on to something. Not, I again remind you, about whether the diet is good or bad, seeing as I don’t express a view on that, but simply that this sort of “research” or “study” sets a very low standard in terms of what we should aspire to as scientists.

At no point in the article is the claim ever made that this is an attempt at a scientific proof of a particular diet. That is why the title includes the words – Occasional Survey. It is simply a group of case reports showing that some patients achieve remarkable cures for their intractable medical conditions simply by following advice, the key point of which is that it normalises hunger. For the truth is that these patients are not dying of obesity etc, so much as they are dying of hunger. Once their hunger is controlled by simple dietary advice, they can start to cure the conditions caused by the overconsumption of addictive, highly processed, carbohydrate-rich foods (made worse by their insulin-resistant state).

I have been in science long enough to understand how people try to divert attention from the message. I wrote about this extensively in Challenging Beliefs. First they always question the methods. The methods I used in this study are entirely appropriate for the extremely limited goals of this paper. That simple goal was to show that some people benefit dramatically and in some cases miraculously from this simple advice. Whether or not they would have benefitted equally from other advice is utterly irrelevant since I am not trying to prove (in this article) that one treatment is better than another. Of course I would guess that 100% of the 127 had all tried the conventional advice and it had failed for them. But I only made that claim if I it was supported by the information I had.

A group of “case reports”? I don’t know about you, but that seems an awfully strong description for a series of self-reported and completely uncontrolled and in most cases unverified narratives. But it’s nevertheless a legitimate description, with a track record in medical literature.

However, because a large group of case reports, as in this case, can create an impression of generalisability or significance where there might be none, we find Johns Hopkins, for example, requiring IRB (institutional review board) clearance for any case studies (or a case series, in this instance) involving more than three participants. No clearance is mentioned in this case.

Again, I remind you that I’m simply saying that the study offers little of scientific merit, and that the SAMJ erred in accepting it for publication – not that the anecdotes are false. (It’s that we can’t know whether they are false or not that is part of the problem.)

As for “I have been in science long enough to know” – I refer you to the point about deflection and conspiracy mentioned earlier. The fact that methods are questioned isn’t evidence that the scientist is a martyr for the truth, as Noakes seems to want to imagine himself here. As Occam’s Razor suggests, it might also be because the methods are questionable.

It’s entirely relevant to question whether the participants would have benefited equally from other advice, precisely because 127 cases offers an impression of significance or generalisability. The goal was “to show that some people benefit dramatically and in some cases miraculously from this simple advice” (my emphasis) – and how do you show that through 127 unverified self-reported anecdotes? If the science already shows this, then it can stand alone, with the anecdotes as illustrations if one so desires. Noakes says (in the paper) that this “data” is “of value” and “challenges current conventional wisdom” – and yes, it would, if we had reason to believe it was replicable. It might well be replicable, but the anecdotes are not evidence for that conclusion.

A key point about South African medical ethics is that if there is more than one treatment options it is ethically unacceptable for a South African practitioner to prescribe only one. My ethical responsibility as an educator and scientist is to bring the attention of my colleagues to the established fact that there is more than one option for the treatment of obesity, diabetes and metabolic syndrome and that the scientific evidence for this is well established in the literature (as recently accepted by the highest Swedish medical authorities).

Having been involved in high-level research ethics myself, of course I’d agree in the main. Except, Noakes is leaving something crucial out of the summary: it’s not only when there is simply “more than one treatment option”. Instead, it’s when there is “more than one effective/proven/viable/etc. treatment option”. This might well become known to be one of those options, perhaps even the best one. But it isn’t known to be that as yet, which is a reality Noakes again evades in the above quotation.

A very important bit

Above, Noakes says “as recently accepted by the highest Swedish medical authorities”. This, in a nutshell, demonstrates his rather casual relationship with reality when it comes to promoting the conclusion he wishes to. You’ll note, as a starting point, that the language is unambiguous – a trusting reader will be left utterly convinced that the Swedes have accepted LCHF as obviously the recommended diet. So, let’s look at the evidence. The quote from his paper reads as follows:

The Swedish National Board of Health and Welfare has concluded that ‘low carb diets can today be seen as compatible with scientific evidence and best practice for weight reduction for patients with overweight or diabetes type 2, as a number of studies have shown effect in the short term and no evidence of harm has emerged … ’

It’s a direct quote, so you’d expect a reference (and quotation marks, which might look a little alien to some potential readers). We have both in this case, and the reference given is to the Swedish Board in question…. oops. No, sorry, my mistake – the reference is to a blog post titled Low-carb for You. The Swedes are eating more butter! In another interesting development, the full quote reads (my emphasis):

Professor Christian Berne, one of Sweden’s leading diabetes experts, had carefully investigated the case against Dr. Dahlqvist and presented his findings to the Swedish National Board of Health and Welfare. He said, “…a low-carbohydrate diet can today be said to be in accordance with science and well-tried experience for reducing [obesity] and type 2 diabetes…a number of trials has shown no effects in the shorter run and that no evidence for it being harmful has emerged in systematic literature researches performed so far. [There is] no scientific support yet for treatments in excess of 1 year. A thorough evaluation of long time treatment results is therefore an important demand on the practitioner.”

So what we learn here is:

  • In the source Noakes refers to in order to support a very strong claim, we find Berne reporting findings to the Board
  • But that quote is presented by Noakes as a resolution of the Board, rather than an opinion expressed to the Board
  • An important bit of the quote is left out, because it’s inconvenient (namely, that there is no scientific support for treatments “in excess of one year“)
  • Notice that this question – around long-term efficacy – was a central theme of my previous blog post that inspired this Noakes essay in response – and his own source makes the same point
  • Lastly, we learn that quotation marks don’t mean the same thing for Noakes as they might to you, in that a sentence like “a low-carbohydrate diet can today be said to be in accordance with science and well-tried experience for reducing [obesity] and type 2 diabetes” morphs, in Noakes’ version, into “low carb diets can today be seen as compatible with scientific evidence and best practice for weight reduction for patients with overweight or diabetes type 2” (I’m not asserting here that he changed the meaning – it’s just odd to quote-and-not-quote at the same time).

The SBU (Swedish Council on Health Technology Assessment) have however published guidelines on diet and obesity – but unfortunately, they’re not yet available in English, so Noakes couldn’t easily have quoted from them in an English-language journal. But let’s see what Google translate can do for us, seeing as we’re able to take such liberties on a blog post.

“SBU has previously addressed food for people with diabetes [link to English pdf]. The results for people with obesity and diabetes, pointing at large in the same direction.”

That direction, according to the English diabetes report, includes bits like this (my emphasis):

  • Scientific evidence is not available to evaluate the long-term safety of moderate and extreme low-carbohydrate diets. This includes cardiovascular morbidity and other complications of diabetes.
  • There is strong scientific evidence that lifestyle intervention, combining a low-fat diet with high fiber intake and increased physical activity, prevents diabetes in people that would otherwise be at high risk for the disease

Back to the Google translate version of the obesity report, which also says (my emphasis):

  • In the short term (six months) is advice on strict or moderate carbohydrate diet more effective for weight loss than low-fat diets advice. In the long run there are no differences in efficacy between weight loss tips on strict and moderate carbohydrate diet, low-fat diets, högproteinkost, Mediterranean diet, diet focuses on low-glycemic load diet or a high proportion of monounsaturated fats.
  • After that obese people have lost weight they can maintain their weight better with advice on low-fat diets with low glycemic index and / or high protein content than with low-fat diets with high glycemic index and / or low protein content. There is no basis for assessing whether even advice, eg, low-carbohydrate diet and the Mediterranean diet is effective in preventing weight gain after weight loss

Once again, it might one day be common knowlege that Noakes et. al. are right. But that day doesn’t seem to have arrived yet, and in the meanwhile, it certainly looks as if support is being appropriated where it doesn’t quite (as yet) exist. This, again, is bad science, if not simply dishonest.

Back to the Noakes comment

The reasons why this information is not taught more widely across the world is not material to this article and whether or not there is a conspiracy is not relevant. The point is that students in South Africa (as in most other countries) are currently taught only one side of a two-sided story. As far as patient care is concerned, that is unethical.

Sentence one, and then two and three seem somewhat contradictory. If students are being misled into providing unethical patient care, surely that must be relevant? But in any case, my point was that if something was obvious, and as evidence-based as Noakes keeps asserting, it would be taught all over the world. He constantly refers to conspiratorial reasons why that isn’t the case, rather than considering the possibility that others don’t think the evidence is as clear as he thinks it is.

Three years ago I decided that it my ethical responsibility to acknowledge publicly that my advice on high carbohydrate diets for runners, widely read in Lore or Running, was wrong for those with insulin resistance/type 2 diabetes/metabolic syndrome since it would contribute to their ill-health in the long term as it has to mine. This article is one outcome of that admission.

I could have kept quiet and hidden my error but I chose not to. Now that this article has been published in the SAMJ (and I have spoken about it at the most recent SAMA conference), South African medical practitioners, perhaps for the first time, have been exposed to the evidence that there is an alternative option that they might like to consider in future for the treatment of these conditions.

The result is that if the 127 patients reported here are any indication, many patients in South Africa with these conditions will be offered another treatment option that before they would not have been offered. I suspect that many will do much better on that therapy than if they continue to follow advice that does not work (for them).

Nothing to add here, except to repeat that the point is precisely that we have no reason to believe that the 127 patients reported here in fact are any indication.

So this focus of this discussion should not be about whether or not I am a good scientist who understands what is and what is not good science.

Erm, no. I choose what the focus of the discussion is on my own website, thanks.

Fortunately in science, there are simple markers of our standing as scientists that are based on hard measureables and not on the opinions of others. These are the h-Index and the number of citations. Anyone who wishes to determine my status as a scientist is welcome to find those numbers and what they mean. Those are measures of scientific influence over a life-time, not as the result of one single good or bad article.

Yes, they are indeed “simple” markers. “Crude” might be another appropriate word, as Prof. Noakes knows full well. They offer a valuable heuristic in making snap judgments, but they aren’t any sort of guarantee of sense or quality in perpetuity. I don’t dispute, and have no reason to dispute, that Noakes has done tremendous work in the past. But that tells us nothing about the present topic, except to make it statistically more probable that he’s worth paying attention to here than many others might be, because of that track record. This doesn’t mean that – once you look at a particular case – you need to grant extra authority to that person if they present weak arguments.

To do so would be to commit the informal fallacy of making (or rather, falling for) an appeal to authority. It’s particularly disappointing when the authority him or herself makes the appeal on their own behalves.

It is sad that this article which should be a celebration of how simple dietary advice may be able to reverse intractable medical conditions in some people (it would have been valuable even if it had reported just a single “cure”) has been used by some to argue what a dreadful scientist I am, who is trying to push some sort of devious agenda that has no scientific basis.

It’s arguably more sad when eminent scientists start practicing bad science, and then doubly so when they defend it as weakly as this. “This article”, meaning my blog post, is about that topic, not about the diet. Readers, or subjects of a post, don’t get to say what a post “should be” about. Furthermore, nobody is being described as being “devious”, or having an “agenda”. Someone is being described as making poor arguments for a conclusion.

My agenda is clear. I want my profession to teach more than one option for the management of obesity/diabetes/metabolic syndrome and to understand that our current dietary advice is in my opinion the cause of so much of our ill-health.

My agenda is also clear. I teach critical thinking, and the Noakes paper, and his responses to criticisms of it (and, general criticisms on social media) provide great classroom examples of how reputations are no guarantee of good sense.

I have spent 3 years researching this topic and am happy that the scientific evidence supporting this position is as powerful as any evidence I have touted in the past (see Challenging Beliefs). However the topic is much more important that anything I have ever tackled since it is the single most important medical problem in the world and is currently out of control and getting worse by the day.

Agreed entirely, which is why I want the science supporting it to be beyond reproach, especially on such obvious grounds.

What this paper shows it that there may be simple answers for what seem to be intractable conditions. That is why the final sentence of the article calls for a properly funded and designed study to test the hypothesis (not proof) advanced by the finding of this Occasional Survey.

As argued above, the occasional survey doesn’t present a case for doing so, because of the quality of the data. Furthermore, we are told by Noakes that non-anecdotal evidence exists – and if this is the case, the anecdotes are superfluous. This was the topic of my last post, so I won’t repeat the argument here.

I would be only too happy if that trial disproves me. But if it shows that a carbohydrate-restricted diet can reverse intractable obesity and some cases of Type 2 diabetes, then we will have shown that the causes of the obesity and diabetes epidemics are much simpler than we believe and that we might be able to do something to protect our future generations from these diseases. Of course, it there is a conspiracy, then it will do all it can to insure that we do not ever make that finding.

Agreed entirely. And of course a scientist should be happy to be corrected (even if it’s sometimes difficult to swallow).

Perhaps we can move the debate forward by focusing on what this paper actually found and how that might be of value in trying to understand what is causing the obesity and diabetes epidemics globally. Then we will be making a positive contribution to the future health of the world.

No, there are different debates. Noakes, and his peers, can move that debate forward. My focus is critical thinking, logical fallacies, the standard of education and so forth. That’s the debate I’m going to “move forward”, and these sorts of examples are great resources for doing so. In fact, they allow for us to make a positive contribution to the current – and future – health of the world too, by helping to inculcate and reinforce clear and cogent reasoning, without which medical science is doomed.

Thanks for the opportunity to express myself more fully and I look forward to your contribution to that agenda should you think it sufficiently important.

It’s vital. But also, that agenda is not my field. This one is.

Honest communication about science

This entry is part 8 of 29 in the series Noakes

It’s easy to lose objectivity when we feel strongly about an issue. Some of the things we feel strongly about might also be of great consequence, making it even more difficult to separate the strength of your emotional commitment from the strength of your argument. Some of the comment following my blog posts regarding Prof. Tim Noakes‘ research (especially on Twitter, where nuance is sometimes in short supply) ask why people like me focus on these issues, when obesity (or diabetes, or whatever) are such enormous problems – and the answer is simple, albeit two-fold.

First, because the more important something is, the more important it also becomes that our reasoning be sound, so that we can stand a better chance of convincing doubters. And second, because there are more problems in the world than simply obesity (etc.), and just because one of those is your focus, doesn’t mean it has to be mine. Furthermore, in what might come as a shock to some, it’s possible to focus on more than one of those problems at a time – you can promote critical reasoning while also caring about public health, for example.

I attended EthicsXchange this morning, a TEDx-style event where 11 speakers spoke on ethical challenges and potential responses to them. The Doctor has written about this event also, focusing on some of the hyperbole (such as the ‘addictive’ nature of sugar) we encountered on the day. Besides a general grumble regarding the oddity of an ethics conference that featured no ethicists, it was a worthwhile event. My favourite presentations were the ones that focused on the complexities and apparent contradictions we sometimes encounter in seeking the good, and I thought that my Vice Chancellor, Dr. Max Price, and Peter Bruce of Business Day did the best job of raising those issues.

It’s the talks on scientific themes that I want to briefly address here. I do so mostly as a prompt to those of us who speak or write about science to remember that we do live in an age of celebrity, short attention-spans and a lack of patience for complex arguments. What this adds up to is beautifully illustrated by a recent xkcd panel, reproduced below:

xkcd on headlines as clickbait

Sensation and hyperbole grab attention. TEDx-style talks are meant to be slick, yes – and it’s also not a bad thing to make science compelling (quite the contrary, in fact). But we should remember that science is about the method, not the conclusion. When we forget to reinforce the method of good science in expressing our conclusions, we’re sending the message that things are a) more certain and b) easier than they actually are. Of course there are permissible shortcuts, or liberties. When we say that we know, for certain, that smoking is a cause of cancer, it’s only a pedant who asks you to confess that yes, of course, nothing is ever absolutely certain and there might be some other factor we haven’t spotted, with smoking and cancer being caused by that, etc.

When we get to a certain level of justification, we can say we “know” something – even though what/where that level of justification is can (rightly) be contested. But what we should not do is say things like:

  • “The literature says that X” – when we know full well that some of the literature says X, while other literature says Y, with no clear consensus having yet emerged.
  • “We now know that X” – where X is really your preferred view, and not at all “known” but instead the subject of significant dispute

And then, there are some words that we just know – going in to our talk, or sitting down to write our column – that people are going to invest with greater significance than is merited. Words like “caused”, or “proven”, or even sometimes, “evidence”.

I’m not saying that we need to include a ream of disclaimers with every sentence. But if a popular science talk or piece of writing doesn’t make it quite clear that there’s room for reasonable doubt, it’s doing a disservice to the goal of getting people to think more critically and clearly about knowledge-claims.

No matter how important the scientific subject under discussion, the goal of promoting sound reasoning is a worthy one too. And there’s no reason why one of these goals has to be pursued at the expense of the other.

 

“Addicted” to hyperbole

This entry is part 7 of 29 in the series Noakes

Some of you might have noticed that recent blog posts here have earned me some antagonism from defenders of the low-carb, high fat (LCHF) diet. In their defence, they of course think that I’m being needlessly antagonistic, especially towards someone (Prof. Tim Noakes) who they think of as doing pioneering – and very important – work in nutrition.

I’d like to try and approach the topic from a slightly different angle here, in the hopes of illustrating what I mean when I say that my criticisms are premised on a concern for exaggerating the quality and consequences of data, in a context of great uncertainty. In the same way as my language and arguments around religion have tempered significantly over the past 3 or so years, in science I’m equally concerned with the example we set as to how to think, where the claims we make should be proportional to the quality and amount of evidence we have.

A comment on one of my previous posts led me to this blog post by Prof. Grant Schofield, in which he responds to a press release from health professionals in New Zealand, decrying low-carb high-fat advocacy. Schofield’s post seems happy to embrace nuance and to acknowledge the limitations in what we can know right now about the long-term effects of LCHF diets, and is to me a great example of how to argue for an outlier position in a way that lures people into serious consideration of your case, rather than giving the impression that you’re being asked to join a religious cult.

As I wrote earlier in the week, the language of science should embrace uncertainty. We should not offer people dogma, both because it dumbs down the process of scientific reasoning, and second (an extension of the first, though) because it encourages people to think in terms of false dichotomies or other poorly defined and crude categories. What’s right is often about nuance, and doesn’t fit in a tweet or headline – and those of us who know better should not encourage a simplistic “X is right/wrong/healthy/good/bad”, especially when we know that’s what the market wants to hear.

The Doctor just tweeted a link to a great piece about “food fearmongering” that makes this point via examples of diet advice and promotions for books and movies about diet that are almost comical in their hyperbole. Food, basically, is trying to kill you – and unfortunately, you’re also addicted to it.

Until fairly recently, I was involved with a multi-disciplinary research team working in the field of pathological gambling, and as a result got to spend five years working with leading international addiction scholars, neuropsychologists, clinicians in the field of addiction, and so forth. In national prevalence studies and other research, I also got to spend a fair bit of time with people who describe themselves as addicts.

The simple takeaway, if I were to distill five years into one sentence, is that addiction is complex, and not a word to be used glibly. Today, anything we happen to like is often described as addictive, and people will talk about “brain scans show that area X lights up” when you eat a Snickers bar, while not thinking that perhaps area X happens to light up when you do stuff you enjoy. Or, that people who are inclined to addiction will find things to get addicted to, but that this doesn’t always mean that the thing in question is intrinsically addictive.

Today, people are variously addicted to sex, love, the Internet, cocaine, carbohydrates, sugar, crystal meth and so forth. But using the same word to describe all these things is profoundly misleading, and is also potentially insulting to people who suffer from the sort of unambiguous addiction that costs you your savings, your family, your health and so forth. To put a mild lack of self-control alongside heroin seems somewhat glib.

Cocaine, for example, often has no physical withdrawal effects. Psychotherapist Marty Klein says that, in 31 years of practice in the field, he’s never seen “sex addiction”, and describes it as a myth. Internet addiction was invented as a hoax in 1995, when Dr Ivan Goldberg took the diagnostic criteria for pathological gambling and adapted them to the Internet.

Internet addiction wasn’t included in the 2013 revision of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) – not even in the “Conditions for Further Study” chapter, that highlights things thought worthy of continued attention. “Internet gaming disorder” can be found in “Conditions for Further Study”, and “gambling disorder” does appear, in a new category for “behavioral addictions”. As I say, it’s complex.

Then, as I’ve written in the past, we might even want to be wary of treating the DSM as authoritative, perhaps especially with regard to the class of behavioural addictions, accused of making a “mental disorder of everything we like to do a lot”. My point is simply that this one word, “addiction”, is being made to do a lot of work – and a term that broad can sometimes appear rather meaningless in consequence.

It’s of course not meaningless for people who do suffer with an addiction of their own. The question I’m asking here: if we start speaking of anything that people struggle with as an “addiction”, what are the consequences of that? I fear that we’re not only encouraging shoddy thinking about addiction (and science, in general), but we’re also encouraging victimhood in that my lack of self-control can now simply be ascribed to the fact that I’ve been snared by the evil Internet, or the seductive candy bar.

And finally, there’s the danger of insensitivity – almost insult – to people who struggle with addictions that destroy lives. While being badgered by a LCHF devotee on Twitter, I was asked “do you have ANY experience with addiction that is not related to some scientific study? So much more to it than that.” In other words, I was being asked if I was an addict.

Now, this was Twitter, so you might say that this sort of thing comes with the territory. But what if I was an addict, really struggling with something, perhaps have just lost a job, or a spouse, or somesuch? Might one not think the question rude, crude, inappropriate – even indefensible? (Regardless, of course, of whether it was relevant or not, in that I was being asked “never mind the data, but do you have an anecdote?”)

I’d certainly think it inappropriate, perhaps even “triggering“, in the contemporary language of social justice. When it comes from someone who works at an addiction clinic, of all places, I’d be even more convinced.

And in this case, that’s exactly where it came from – a person offering treatment for “sugar and carbohydrate addiction”. The field of addiction – and addicts themselves – could do with us being a little more careful about the language we employ, and the categories we use to describe the things we enjoy.

Problems with evidence-based medicine aren’t a license to make stuff up

This entry is part 6 of 29 in the series Noakes

In the paper that brought the idea of evidence-based medicine (EBM) to prominence, Professor David Sackett et. al. wrote that

Evidence based medicine is the conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients. The practice of evidence based medicine means integrating individual clinical expertise with the best available external clinical evidence from systematic research. By individual clinical expertise we mean the proficiency and judgment that individual clinicians acquire through clinical experience and clinical practice. … By best available external clinical evidence we mean clinically relevant research, often from the basic sciences of medicine, but especially from patient centred clinical research into the accuracy and precision of diagnostic tests (including the clinical examination), the power of prognostic markers, and the efficacy and safety of therapeutic, rehabilitative, and preventive regimens.

In short, EBM is about integrating the best available research knowledge with the expertise of clinicians, who might – and often do – spot something that a model or a manual might not recognise as significant. As much of a naturalist as you might be – and I’m a very committed one – raw data exists in a context, and the context might often be a significant clue in telling you what data are relevant, and how they should be interpreted.

downloadSo I share some of Dr. Malcolm Kendrick’s concerns, when he writes that “EBM is now almost completely broken as a tool to help treat patients” thanks to the “evidence” being susceptible to corruption by vested interests, and pharmaceutical companies in particular. If you fund enough research, and suppress results that you don’t like, it’s certainly possible to end up with all the “evidence” pointing in a favourable direction. Favourable for you, that is, but not for the patient.

But the fact that something is funded by a pharmaceutical company doesn’t guarantee bias. There’s a difference between being cognisant of potential biases, and writing something off in advance, just because of whence it came. That sort of pre-emptive dismissal is a logical error called “the genetic fallacy“, and you can tell when it’s being committed if someone stops paying attention to the evidence at all, or starts claiming that they don’t need to even bother doing so. Like this, perhaps (from Kendrick’s post):

Some years ago I stated that I no longer believe in many research papers that I read. All I tend to do is look at the authors, look at the conflicts of interest, look at the companies who sponsored the study, and I know exactly what the research is going to say – before I have even read the paper.

I have also virtually given up on references. What is the point, when you can find a reference to support any point of view that you want to promote? Frankly, I do not know where the truth resides any more. I wish to use evidence, and the results of clinical studies, but I always fear that I am standing on quicksand when I do so.

We are at a crisis point. Medical research today (in areas where there is money to be made) is almost beyond redemption. If I had my way I would close down pubmed, burn all the journals, and start again, building up a solid database of facts that we can actually rely on – free from commercial bias. But this is never, ever, going to happen.

It’s rather alarming to see the person responsible for writing The Great Cholesterol Con – and for encouraging most of us to stop taking statins to lower cholesterol – professing “I do not know where the truth resides any more”. (If he really means that, a career in anthropology rather than medicine might suit him better, I’d suggest, in that he’s already learnt a key mantra of the field.)

Another peculiar thing you’ll find on his website represents quite a cunning stratagem. You see, he’s talked himself into a bit of a bind with this “don’t trust The Man” stuff – if he ever wants to sell you something like a drug, how could he offer you “evidence” in support of it’s efficacy, assuming that he or someone else with a vested interest was involved in that research?

Easy – by redefining what conflict of interest means. For him only, mind you – not for others, where it means that you can’t trust them, and don’t even have to read them to know that you can’t trust them. In his “Disclosure of Interest” page, he notes “I have become the medical director for a company making a heart health supplement called ProKardia”, for whom he does paid consultancy work. And here’s the cunning bit:

If I do write about ProKardia or any of the ingredients in ProKardia, in a positive light, you need to know that I have a financial interest. I did not use the word conflict of interest in this statement, as I do not believe I have a conflict. I have become involved in developing, and using, a product that I entirely believe to be a good thing.

Got that? He has a financial interest alone, but no conflict. Authors of papers with connections to something he doesn’t trust, or research sponsored by pharmaceutical companies, always represent a conflict – and you don’t even have to read the paper in question to know this. (Which, amusingly, means that even if they were to try to insert the same Humpty Dumpty clause into their papers, Kendrick would never read that either.)

I say “Humpty Dumpty clause”, because the book Alice in Wonderland contains this fabulous line: “‘When I use a word,’ Humpty Dumpty said in rather a scornful tone, ‘it means just what I choose it to mean — neither more nor less.'”

It’s the same causal relationship to what words – and evidence – means that allows for claims that sugar is addictive (as addictive as cocaine, according to some), or that Harvard have endorsed low-carb high-fat diets. They haven’t – they’ve just said that carbs can sometimes be worse than fats, particularly the “bad”, saturated fats – yet the LCHF proponents cherry-pick this as support, even though the same group are explicit that the type of fat matters, and that animal fats remain something to be cautious about.

Or, it’s this casual relationship that allows for claims that Sweden has officially adopted the LCHF diet, even though the report – now finally available in English (the summary, at least), though that didn’t stop English speakers like Tim Noakes from relying on blog sources as authoritative on what it said – actually says (my emphasis):

in the short term (six months), advice on strict or moderate low carbohydrate diets is a more effective means of achieving weight loss than advice on low fat diets. In the long term, there are no differences in the effect on weight loss between advice on strict and moderate low carbohydrate diets, low fat diets, high protein diets.

I realise that this is just one element of the debate, which includes diabetes, heart disease and so forth. But these are two examples of scientists cherry-picking data that happens to support something they want to argue for – or that can be made to appear to support it, so long as you whip up enough hysteria, or persuade them that there’s some conspiracy afoot.

As Mark Wallace points out in piece for The Guardian on “addictive” sugar, “if the issue is people failing to act responsibly, then it won’t be rectified by treating them like children”. To that, we can add “treating them like fools”.

And when the same people doing the cherry-picking are giving themselves licence to simply ignore research they don’t like, and to dismiss conflict of interest issues (in their case, but not for you) with a regal wave, they stop being scientists, and start becoming shills.

Faith healers and medical deceivers

This entry is part 4 of 29 in the series Noakes

On the last night of January, I participated in a rather interesting hour of radio, during which Hlomla Dandala hosted a interview with me and someone claiming to be a faith healer. The faith healer’s name is Pastor Louisa, and you can find some information on her ministry – which includes curing people of AIDS – on her website.

I do have a recording of the show, but haven’t yet found a way to convert it into something that plays outside of the TuneIn Radio app on my phone (informed advice on this is welcome) – if I do get it converted, I’ll be sure to post it here.

What became clear fairly on in the show is that Louisa is not a charlatan, in the sense that she’s knowingly exploiting others. She was desperately sincere, and also, unfortunately, sincerely confused. When invited to facilitate a miracle over the phone to someone who called in, she engaged in a few minutes of shouty, enthusiastic prayer and exhortations to be confident and inspired, after which she asked the caller  whether she “felt better”.

Yes, said the caller. I then asked – “so, does that get added to your list of miracles performed?”. Yes, said Pastor Louisa. On those weak standards, all of us perform dozens of miracles every day – just figure out what language people like to hear, or what buttons they like pushed, make them happy, and then claim to have performed a miracle!

Also, she made it clear that she never tells people to stop taking their medicine. Dandala asked her how she knows whether it’s the prayer or the medicine that heals… and the predictable answer that she gave was that she “just knows”. As far as I can determine, then, she gives her god the credit for the job performed by modern medicine.

You’ve heard how this (faith healing) works before, I imagine, or rather, how it doesn’t work. On the recommendation of Dan Dennett, I watched the documentary Marjoe a few years back, and it’s a wonderful expose of charismatic preachers and healers, involving Marjoe Gortner taking a documentary crew behind the scenes of his final revival tour, held after he had already lost his faith. Watch it if you can, but basically, if people want to believe something strongly enough, it’s difficult to stop them doing so.

The difficulty in talking to Louisa was in resisting the impulse to mock, but instead to feel sympathy for her confusion, and the desperation of those who take her seriously. I failed in this effort at least once, when she spoke about how she had to stop talking to us because she was out in the open, under a tree, and it was cold (this was late at night). I suggested that a miracle might sort this out – after all, if she could cure Aids, what’s the problem with a little heating?

Failures of good grace aside, these people can be dangerous, especially in communities we don’t often hear about, where faith healers and other quacks can do their thing without being exposed to scrutiny. Communities like the Amish are a similar problem. And the overarching problem we all have in a constitutional democracy is in striking the balance between objective application of the law and respecting the various freedoms we believe people are entitled to, like subscribing to and practicing a religion.

For adults, there’s less of a concern regarding people being free to harm themselves than there is for children, who can’t be expected to know any better. But desperation, and poor educations, mean that adults are also sometimes more gullible than one would like, which is why it’s incumbent on all of us to speak out against quackery where we find it, while still trying to avoid being gratuitously cruel to those we criticise.

And those of us in positions of authority should perhaps be most careful, because their trust is vested in us, and they spend money, time and attention on us.

Someone getting a lot of attention right now is Professor Tim Noakes, as he goes around the country giving talks and radio interviews to promote the book he’s recently co-authored, The Real Meal Revolution. During a recent interview with Redi Tlhabi, he informs listeners (at 38m40s) that there is “absolutely no risk” involved in cancer victims trying the ketogenic diet, because it’s proven that starving cancer of carbohydrates is an effective treatment.

Well, yes, it can be. But as he so often does, he’s cherry-picking, or simply believing in the version of “science” that suits his agenda. Because according to the Sanford-Burnham Medical Research Institute, and other sources,

Many scientists have tried killing tumors by taking away their favorite food, a sugar called glucose. Unfortunately, this treatment approach not only fails to work, it backfires–glucose-starved tumors get more aggressive.

This is only true for some glucose-starved tumours, to be sure, but it still means that saying “absolutely no risk” is absolutely untrue, and that Noakes is giving advice – to an audience of thousands – that stands a good chance of harming a listener who happens to have the sort of cancer that responds aggressively to a low carbohydrate diet.

As I’ve said many a time, this isn’t the approach of someone who is a responsible scientist. But, just like the faith-healer, I think he’s utterly sincere, and utterly committed to fostering our good health. More the pity, then, that he’s unable to see how his religious fervour might end up achieving the opposite goal, at least for some. And how – consistently – he’s wreaking havoc on basic principles of critical reasoning, and setting a terrible example for budding scientists everywhere.

On causes, Noakes, and making prudent claims related to diet

This entry is part 5 of 29 in the series Noakes

Three pieces related to diet and the low-carb high-fat fad are worthy of highlighting this week, because all of them are a counterpoint to the “sugar is addictive and you’re a victim of a conspiracy” seam that continues to be mined by the likes of Professor Tim Noakes. The first is by Gary Taubes, who Noakes cites as being responsible for removing the scales from his own eyes, and the second is a response to Taubes by Dr David Katz, who says that Taubes is asking the wrong questions.

You can read those pieces yourself – the only aspect I want to highlight here is how moderate Taubes’ tone is. He acknowledges that the science isn’t settled, but that he’s biased in favour of “sugars and refined grains” being the problem. He even includes the rider that “we all have our biases”. Indeed we do. But on that minimal (and yes, selective) quote, Taubes could be saying the same thing that mainstream nutrition science is – which is at a significant remove from the claims made by Noakes, who speaks as if there’s no doubt that carbohydrates are the cause of most of our ills, and that most of our ills can be eliminated (or at least managed) by eliminating the majority of carbs from our diets.

In other words, Taubes at least speaks as if he acknowledges the possibility of being wrong. Noakes, by contrast, leaps straight to rather humorous epithets when people disagree with him, calling them victims of “Group Think”, “statinators”, or “The Anointed”. Alternatively, he’ll poison the well by making very generalised aspersions about funding, as if to pre-emptively taint any claims that are being made. It’s tinfoil-hat territory, and in short, in no way confidence-inspiring, at least not for those of us who want to resist signing up to a cult.

And it’s the third piece that merits your careful attention, if you care for holding science and scientists up to rigorous and principled scrutiny. Not because it says anything new, but because it quite clearly articulates a very essential, and simple, principle of scientific reasoning. Namely: what question is being asked, and what sort of an answer will we be willing to accept as legitimate? The key passage for me – at least in terms of highlighting how Noakes is compromising critical thinking – is this one:

It seems likely that we were seduced by the early successes of epidemiology with point-causes with large effects — infectious diseases — and we were similarly seduced by Mendel’s carefully engineered successes with similar point causes — single genes — for carefully chosen traits, but these are paradigms that don’t fit the complex world we’re now in. What Mendel showed was that causal elements were inherited with some specifiable probability, and he did that in a well-posed setting (selective choice of traits and highly systematized breeding experiments). But Mendel’s ideas rested on the notion that while the causal elements (we now call them alleles) were transmitted in a probabilistic way, once inherited they acted deterministically. Every pea plant with the same genotype had the same color peas, etc. We now know that that’s an approximation for some simple situations, but not really applicable generally.

This passage reminds me of the dispute between Humean accounts of causation and what I’ll call the “causal powers” account, described very usefully in Harre and Madden’s 1975 book, Causal Powers: A Theory of Natural Necessity. In short, the distinction could be captured in discriminating between the fact that high carbs typically mean high quantities of refined foods, sugars, a sedentary lifestyle etc. and the fact that neither does it need to mean that, nor that those causal factors exist in isolation.

By way of example: To say that aspirins relieve headaches is to say that, because of its nature, an aspirin can relieve a headache while a laxative cannot. The means by which it achieves this are neither occult nor unfathomable – it does not have this power in spite of its nature; it is rather because of its nature that this is possible.

In cases like these, scientists are able to investigate the chemical composition of an aspirin, and then to figure out why it has the effect it has on the body, describable in terms of chemical reactions within the body. An aspirin’s power to relieve headaches is furthermore something which exists even when the tablet is not being used to relieve a headache. When we say that aspirins relieve headaches, we are saying that in a particular situation (essentially, a person having a headache), aspirins will be more effective than other things, because they by nature have the power to relieve headaches.

When we open the medicine cupboard, looking for something to relieve our headache, we choose aspirin over a laxative because we think or indeed know that it currently has such and such powers. The difference between a placebo and an aspirin is not that the aspirin will relieve the headache and the placebo will not, as there will be situations in which the aspirin is ineffective or the placebo effective, the difference is in the natures of the two substances, and that, by nature, aspirins generally behave in such a way as to exhibit the power to relieve headaches.

Harre and Madden go on to draw a distinction between enabling conditions and stimulus conditions, where enabling conditions are those that ensure that a thing is in a state of readiness to create a certain effect, and stimulus conditions which actually bring about an effect, assuming that the enabling conditions have been fulfilled. In other words, we’re talking about potential causal factors rather than absolute causes.

Enabling conditions for an aspirin would be that the aspirin is in a state whereby it could possibly alleviate pain – if an aspirin is consumed after its sell-by date, the possibility exists that certain changes have taken place in its chemical structure, resulting in that aspirin not being able to relieve pains. So, assuming that the aspirin is enabled in this way (this is not to say that this is the sole enabling condition), what are the stimulus conditions which actually bring about the response from the aspirin that causes the headache to be relieved?

To relate that to diet, what are the conditions under which carbohydrates cause obesity, or type 2 diabetes, or whatever? Noakes would respond to say that the conditions are quite clear – namely that they obtain when one is insulin-resistant. But he only mentions this qualification when challenged to do so. Page 22 of the Real Meal Revolution states quite plainly – without any qualifications – that “fat does not make you fat. Carbs do”.

The very next page introduced insulin, but without any suggestion that we might have variable insulin reactions to carbohydrates. And the page ends with a generalised warning of a “near-perpetual cycle of weight gain. Unless, of course, you break the addiction…”. Never mind, of course, that the word and concept of “addiction” is being used in a rather quackish sense here.

In other words, the qualification that this only applies to some is introduced grudgingly, under duress, whereas his generalised opposition to what he dubs the ‘prudent diet’ recommendations gives the clear signal that he’d prefer for dietary guidelines to suggest a low-carb high-fat approach, for everyone. As he says in an interview in early February 2014, he’s calling for a “return to your dietary roots, bringing you back to the way humans are meant to eat and returning your body and mind back to the trim, happy, energised state our ancestors experienced thousands of years ago. They didn’t get fat or suffer from obesity, diabetes or other lifestyle illnesses” – and as he’s pointed out in every talk I’ve heard and read, those dietary roots (allegedly) involved high fat diets and low carbohydrate intake.

Yes, he does allow for wiggle-room, with some of us allowed to eat “a maximum of 200 grams of carbohydrates a day, depending on your insulin resistance”. But he’s also claimed that 60% or more of us would benefit from the LCHF diet, so it seems clear that – unless you prove yourself carb-worthy by whatever standard he sets – the presumption is that you, like him, should avoid carbs.

Here’s the thing: dieticians already know that excessive consumption of carbs is a bad thing, especially when they come in super-refined forms, and especially in the form of sugar. If that were all Noakes were saying, nobody would care. He’s saying something more, which is that we don’t need to fear saturated fat, and that the proportions of proteins and saturated fat we consume should increase, at the expense of the proportions of carbs.

When making these sorts of claims, he cites sources like the Harvard School of Public Health, even though they include the (standard) cautions against saturated fats. Just as he and his followers have been claiming that Sweden has “officially” adopted LCHF, even though they’ve done no such thing. And when faced with challenge, the retort is that you’re indulging in “Group Think”, as though conspiracy theory isn’t a perfect example of exactly that.

Take the example of that tweet, pasted above. In Noakes-science, that’s evidence (or so it seems). For the rest of us, we might say a) that’s a post-hoc (ergo fallacious) argument; or b) that it seems fairly straightforward to intuit that high cholesterol is sometimes a potential causal factor, but never a necessary one, in causing heart attacks; and c) what about the other 50% – does their elevated cholesterol not mean anything, on this model?

As I’ve said before, I really hope he’s right (leaving aside the fact that non-human animals will be killed in even higher numbers if his diet takes off). But damn, I wish he could try sounding like a scientist for a change.

A Quixotic note regarding Noakes

This entry is part 9 of 29 in the series Noakes

That title, because I do think it an implausible and potentially unreachable goal to convey (relatively) subtle points about epistemology when the points in question relate to an emotive topic, namely our health and diet.

According to a few folk on Twitter, my blog posts on the topic have amounted to “rabid attacks”, which I find distinctly odd, seeing as the only ad hominem – and emotionally animated rather than merely critical – engagements I’ve seen have been directed at those of us who dare to challenge anything related to the LCHF diet and its proponents.

So, in bulleted points to try to minimise confusion, here are my concerns and positions. These are the same concerns and positions I’ve expressed from the start, contrary to what some “rabid” comments have claimed in response to my posts and columns on the topic.

  • Regardless of the efficacy of the LCHF diet in treating various conditions, and regardless of the truth or falsity of hypotheses assumed by the LCHF diet, we should all have a concern for good scientific thinking, and clear reasoning in expressing the conclusions we’d like to see adopted. Science does not work in absolute truths – it’s an inductive process, whereby we chisel away at falsehoods to arrive at a clearer understanding of what’s most likely to be true.
  • That project of triangulating on the truth is harmed by expressing scientific claims in absolutist language, and by creating movements akin to cults, where people are more likely to forget that anecdotes aren’t data, that being wrong in the past doesn’t guarantee you’re right now, that emotional commitment leads to confirmation bias, and so forth.
  • My criticisms of Noakes have mostly been that – whether or not he’s right – he doesn’t present his case in a way which demonstrates sound scientific reasoning. We reveal ourselves when we “show our working”, and it’s not reassuring to see anti-vaccine quacks and evolution-deniers quoted approvingly when arguing for LCHF. It demonstrates a desperation to make a case, and a lack of sound judgement.

Likewise, not focusing on the details, or the evidence, is a bad sign. Take this tweet as example:

  • It references the UCT Health Sciences Centenary Debate between Dr. Jacques Rossouw (my father) and Noakes. But notice how it references it – by dismissing me as a latecomer who somehow rushes in to defend my father’s cause. However, the evidence shows that I was writing about this 9 months before that debate, and that Rossouw père hasn’t been engaged with Noakes at all for around 20 years, and only got involved in this debate on an invitation from the Medical School when an ex-colleague had learnt that he was coming here on holiday. It misrepresents (a truly rabid critic might even say “lies”) to further a particular narrative.
  • Likewise, it’s misrepresentation to tweet (as Prof. Noakes regularly does) links to Noakes’ SAMJ article criticising the WHI study that Rossouw directed without acknowledging that there were at least two responses to the Noakes article, arguing that his criticisms are misguided.
  • A summary of the problem might be this: Noakes’ audience is primed to believe, and primed to think that critics are deluded, because of the narrative they’ve been told, and because their anecdotal experience (in the short-term, at least) confirms that narrative. And then, the way in which Noakes responds to critics (e.g. “I ignore what I consider not to be evidence“) seems to do little to help them think critically about science, because criticism starts – and sadly, also ends – with the charge that traditional views of diet are deluded.
  • It’s entirely possible that the long-term harms of high meat or fat consumption are overstated, and therefore that Noakes is right. But I can’t imagine him saying that it’s entirely possible that we don’t yet know if there are long-term harms from following his advice, or that it’s entirely possible that a moderate diet, involving a focus shift away from any single or particular macronutrients, might be best for most people. Nothing seems possible, except that he’s right.
  • Then, the LCHF crowd get relationships and potential taint utterly wrong in any case – just because someone works for “Big Food”, the FDA, the South African Heart Foundation or whatever – or is someone’s father/son – doesn’t absolve you of the need to make and respond to arguments. Sure, the connections can lead to the increased probability of some sort of bias, but you still need to show the bias, and not simply evade challenges by asserting it.

I’ve written at length about logic, epistemology, scientific reasoning, anecdotes and their irrelevance, and other issues to do with Noakes’ warrant for presenting his case with the degree of certainty that he does. I’ve said very little about the diet itself, because that is not my focus – and it doesn’t need to be my focus.

The retort that there is “bad science” on the other side is not compelling, in that it’s a) bad science (if it is) mostly because the LCHF people think it reaches entirely the wrong conclusions; and/or b) because it uses poor data. My accusations of “bad science” are premised on the selective quotations, dubious authorities cited and so forth as demonstrated in social media, rather than being about “bad science” in the sense described in (a) and (b) above.

To capture the essence of the only things I have ever said about diet specifically

  • I’m concerned about the affordability of the LCHF diet for poorer populations.
  • I can see how people might be concerned about animal welfare and an increase in the farming and killing of animals. I eat meat, but think it’s a moral failing that I do – and furthermore, I think that the immorality of meat-eating will be the subject of a moral consensus in my lifetime.
  • Independent groups like the Harvard School of Public Health continue to caution against excessive consumption of saturated fat.
  • I’m not at all persuaded by what LCHF folks assert as evidence of the failure of the so-called “prudent diet” – first, because it’s not at all clear that people have ever been eating that way (in general); and second because it caricatures dieticians as having recommended a diet that they claim they aren’t recommending at all. A series of blog posts at Nutritional Solutions are worth reading in this regard.
  • In short, the increase in obesity and the like still seems mostly explicable by the advent of television, increased access to motorised transport, desk-bound lifestyles, and excess consumption of food.
  • Yes, it certainly seems true that fats (in general) have been demonised far more than they should have, and that some of us might have started eating too much of other things (including carbohydrates, especially in the form of sugars) to compensate for a flavour-deficit after shunning fat.

This doesn’t, however, automatically lead to the conclusion that carbohydrates are in general bad, nor to the conclusion that we need no longer be at all concerned about the long-term effects of a diet with significant levels of saturated fat. “Real food” is good, sure – and refined carbs are “bad”. And what that means is, when you carry on eating your modest portions of a balanced diet (which is surely what you eat, right?), you should continue to be wary of including too many processed and refined foods.

That’s what I’ve always been told. What’s “new” is that fats aren’t as bad as we thought, and I (along with many of you, no doubt) were misinformed when we were told that they were rather evil. The truth is probably in the middle somewhere – and why replace one exaggerated position (“fats will stop your heart!”) with another (“carbs will give you diabetes!”).

As Oscar Wilde had it, “the truth is rarely pure and never simple”.

Epistemic prudence, Noakes, and the limits of authority

This entry is part 10 of 29 in the series Noakes

Wittgenstein said “Whereof one cannot speak, thereof one must be silent”, and that quote seems as good a place as any to kick off a post on appeals to authority, the death of expertise, and the boundaries of disciplines. As I argued in a 2012 column, agnosticism is often the most reasonable position on any issue that you’re not an expert in (with “agnosticism” here meaning the absence of conviction, not necessarily the absence of an opinion). Continue reading “Epistemic prudence, Noakes, and the limits of authority”