The plaudits seem to be piling up for Bad Science and the Truth about Healthy Eating1 by Anthony Warner, better known as ‘The Angry Chef’ for his foul-mouthed assaults on the pseudoscientific pretensions of the alternative health and diet industry. Well, my advocacy for alternative farming has never really been strongly grounded in nutritional considerations, and to be honest I find a lot of the book a pretty convincing takedown of some of the wilder shores of contemporary food faddism. So perhaps I’d be best off focusing on other things. But there are things that trouble me about Mr Angry’s line of argument, which bear on the general themes of this blog, so I’m going to conclude my recent series of critical book reviews with a look at his opus. Because you see, for someone who’s so angry about bad science, there’s a remarkable quantity of bad science in the book. The reason, I think, is because Mr A is less interested in science than in SCIENCE, and the result of this is…bad.
I’ll explain the difference between lowercase science and uppercase SCIENCE towards the end of this essay. But first I want to home in on the chapter of Mr Angry’s book in which he most reveals his penchant for bad science – Chapter 7 in Part II of the book called “When science goes wrong”, which focuses on the Paleo diet.
The Paleo diet idea in brief is that human diets changed radically after the widespread global adoption of agriculture starting around 10,000 years ago. This involved the substitution of energy dense foods based on cereals (and, later, also sugar) for the less carb-heavy fare to which our species and its antecedents had previously been accustomed. According to Paleo diet proponents, the high-energy input and low-exercise output regimen of modern life is associated with many of the chronic diseases of later life that plague us today, because a mere 10,000 years or less of agricultural lifeways has been insufficient for full evolutionary adaptation. There are numerous additional complexities to the Paleo diet idea which are set out in Loren Cordain’s eponymous book2, but that, I think, will have to suffice as a thumbnail sketch.
Trying to sort the chaff from the grain in Mr Angry’s attempted refutation of the Paleo hypothesis, if that’s not an inappropriate metaphor, I hope it’s fair to summarise it by way of the following six points:
- The Paleo hypothesis misunderstands evolution, since it assumes that evolution creates “one perfect being at a single point in time and then chug[s] along unaltered as the world changes around it”3. The truth is that “evolution doesn’t stop” – which Mr A supports with reference to the post-agricultural emergence of lactose tolerance.
- There were many different Palaeolithic peoples who ate widely different diets, so it’s impossible to determine what ‘the’ Paleo diet should be.
- Palaeolithic peoples did, in fact, consume carbohydrates.
- The Paleo hypothesis is sexist: its contemporary proponents tend to be men, and their “hypothesised Palaeolithic lifestyle” involving relatively high levels of meat consumption is “likely to appeal to a certain retrograde misogyny – the muscular male hunter bravely wrestling bears, while the women tend the children and pick a few berries”.
- The Paleo hypothesis romanticises the Palaeolithic period, a point that Mr Angry makes by various characterisations of it such as this: “As a species, we did all of our evolving in the golden age, when men were men and women wore bikinis made of mammoth fur”.
- The Paleo hypothesis involves a dangerous refusal of expert knowledge, because despite the fact that there’s a grain of truth to some of it and that it has a few academic advocates “in accepting the misunderstanding of science that underlies it there is a real danger of abandoning the tenets of reason. Once you reject the voices of real experts in favour of charismatic advocates with a prettier story, you leave yourself open to packs of pseudoscience wolves.”
What to make of all this? First, I’d draw a distinction between points 1-3, which are at least potentially good scientific objections to the Paleo hypothesis, and points 4-6 which are bad scientific objections – in fact, they’re not ‘scientific’ at all. Points 4 and 5 are ad hominem criticisms of contemporary people who espouse the Paleo hypothesis. I have no idea if they’re well-grounded and I don’t really care, because to use the kind of language favoured by Mr A himself, if it’s true that pre-agricultural diets are better for human health then, scientifically speaking, it doesn’t matter a flying f*** what views people espousing such diets take on matters of gender or history.
Point 6 is not so much an unscientific objection to the Paleo hypothesis as an anti-scientific one. For, as Mr A is at pains to emphasise throughout his text, the modus operandi of science, the whole reason for its spectacular success, is that it doesn’t satisfy itself with the ‘expert’ opinions of people in authority, but relentlessly questions received wisdom. For sure, if you want to take an intellectual shortcut on a scientific matter you’re probably better off asking for the opinions of someone who has some relevant scientific qualifications than those of someone who doesn’t. But science proceeds by way of empirical hypothesis-testing, not expert opinion-making, and the glory of it is that ultimately it stands or falls irrespective of anybody’s opinions. The criticisms voiced by the experts Mr Angry cites seem to take aim more generically at the idea of ‘a Paleo diet’ rather than any specific hypothesis underlying it. In any case, his contention that the Paleo hypothesis is rejected by all the experts apart from “a few academic advocates to give it some validity” is rather tendentious. There seems to be a reasonable body of writing in peer-reviewed journals that is broadly supportive4.
So I think we can reject points 4-6 as bad scientific objections to the Paleo hypothesis. Kind of weird to find such bad science in a book critiquing bad science, huh? Well, I think Mr A has his reasons, and I’ll come on to that soon.
But first let’s look more closely at the possibly more plausible points 1-3. Mr Angry is on firm ground in arguing that evolution doesn’t create perfect creatures at particular points in time and then stops. That certainly would be a misunderstanding of evolution. But, so far as I can discern, it’s not what proponents of the Paleo hypothesis actually think. Mr A doesn’t provide any references to support his characterisation of the evolutionary theory behind the Paleo hypothesis, which strikes me as intellectually sloppy. I think I’m detecting the sweet, dry aroma of straw, shaped into human form.
I’ll come back to evolutionary theory in a moment but, just to pick up on points 2 and 3, here is where we may be getting somewhere. If it turns out that Palaeolithic diets were typically as rich in carbohydrates as contemporary ones (and perhaps more to the point, as rich in simple carbohydrates) then that really would throw a spanner into the Paleo hypothesis. Here, Mr A does cite a paper, which argues that starchy foods were important in the pre-agricultural diet5. But so far as I can tell it doesn’t argue that carbohydrates or simple carbohydrates formed as significant a proportion of the diet as they do today – indeed, other research papers suggest the opposite6. Mr A himself mentions that among adults in the contemporary UK 12.1% of their dietary energy comes from added sugar, and for 11-18 year olds the figure is what he calls a “a genuinely shocking” 15.6%. It’s clearly true that Palaeolithic diets were quite varied and that Palaeolithic people would have sought out sources of carbohydrate when they could. But how many of them regularly consumed sucrose or simple carbohydrates more generally at the kind of levels reported by Mr A for the contemporary UK? My guess would be few, if any. And if that’s so, then there’s surely a prima facie case for the plausibility of the Paleo hypothesis.
Let me now briefly try to reconstruct the rudiments of a plausible Paleo diet hypothesis which is robust to the kind of objections raised by Mr Angry. First, I don’t think it’s scientifically controversial to say that there are widely consumed foodstuffs today that have potentially anti-nutritional or morbid properties as well as nutritional ones – soy, rape (canola), wheat and sugar spring to mind. There are ways of trying to minimise these properties – plant-breeding, preparation methods and dietary diversity among them. But I think it’s plausible to suggest that consumption of the crops I’ve mentioned – all huge global commodity crops – is likely to be higher than in pre-agricultural diets7.
Second, let us consider the nature of disease and exposure to risk factors associated with it. In some cases, diseases and disease-causing agents are experienced as binaries: you either have malaria or you don’t, you were either exposed to asbestos or you weren’t. But in many cases exposure is a continuous variable – for example, high blood pressure is associated with various health problems, but blood pressure is distributed continuously within populations. The point at which we define someone as suffering from the disease of hypertension is essentially arbitrary8. I hypothesise that the same may be true for the negative effects of foodstuffs like sucrose and gluten. Some people are highly susceptible and may display various morbid symptoms at low exposures, while others will be utterly impervious. The rest of us will be strung out along the continuum between these two poles. We won’t, for example, experience morbid symptoms simply by eating a few slices of bread, but if we eat a lot of bread over many years it’s possible that some of us eventually will experience morbid symptoms as a result. So, for example, the notion criticised by Mr Angry that no amount of sugar consumption is safe may be overly alarmist, but isn’t necessarily without scientific foundation. And one of the findings of preventive medicine is that population health is improved more radically if exposure to the risk factor is reduced by a little bit across the whole population than by a lot only among those most susceptible to it9. So even if in some cases (like coeliac disease, for example) there’s a genetic aetiology which isn’t simply distributed continuously, there may still be a case for taking a ‘less is better’ approach.
Third, let us consider the nature of evolution. Organisms, including humans, are born with characteristics substantially inherited from their parents which have usually developed over the evolutionary long haul because they conferred adaptive abilities to cope with the kind of environments the species in question experienced. Often, the kind of environment an organism experiences is similar to that experienced by its parents and ancestors, but sometimes environments change. In these circumstances, stronger selective pressures act upon the inherent variability within the species, favouring those organisms with characteristics that are better suited to the new environment. But, in the short-run at least, natural selection is a blunt instrument, acting only upon relative reproductive success. Therefore, if an organism experiences an environmental change that reduces its adaptive fitness in the post-reproductive phase of its life the selective effect will be slighter (though not, as discussed on this blog a while back, zero). And even in the case of stronger selective pressures, it can take a long time for natural selection to ‘catch up’ with the environmental change by progressively eliminating less adaptive characteristics in the population.
Fourth, let us consider the nature of the historical human diet. I’d hypothesise that it’s evolutionarily adaptive for humans to like and favour nutrient-rich foods such as sugar and other carbohydrates, fat, meat and other protein-heavy food. But in the hunter-gatherer situations that have typified the greatest proportion of our species and its antecedents’ time on earth, these foods were usually relatively hard to come by10. Mr Angry states with appropriate caution that we don’t really know in detail what our Palaeolithic forebears ate, and – as I’ve mentioned – he cites a research paper that suggests carbohydrate was an important part of our diet before agriculture, but doesn’t suggest how important. He also states that “even the evil grains were widely consumed for much of [the Palaeolithic period]”. This time he provides no supportive evidence for this statement, but there are research papers that suggest otherwise11.
One other little notion I’d like to throw into the mix here is the finding that rates of diabetes in societies consuming modern ‘western’ diets seem to be much higher than those of hunter-gatherer societies and others following ‘ancestral’ diets, but rates among people who’ve switched from an ‘ancestral’ diet to a modern western one may be higher still12.
OK, let me try to parlay all that into the Angry Farmer’s own personal Paleo hypothesis, which goes something like this: most ancestral human populations were adapted to diets lower in gluten-containing wheat, sugar and other simple carbohydrates than is typical of the modern western diet. Exposure to higher levels of these foodstuffs in the contemporary western diet is causally associated with various chronic diseases of later life such as diabetes and heart disease. Evolution hasn’t ‘stopped’ with the invention of agriculture – there is likely to be a selective effect favouring people who are less susceptible to such chronic diseases. But the effect is likely to be relatively weak and has not yet had time to eliminate the negative consequences of a cereal and carbohydrate-rich diet. Therefore, to reduce the risk of these disease outcomes it may be prudent for people to reduce their carbohydrate and wheat consumption. Lactose tolerance is another post-agricultural evolutionary adaptation – and one where the selective effect is likely to be stronger than in the case of gluten or carbohydrate tolerance because it confers the ability for whole populations to exploit new pastoralist niches that would be harder to occupy for lactose intolerant people. The weaker selective effect of post-reproductive chronic illness is inoperative in this case. Lactose tolerance is, however, just about the only clearly identified post-agricultural dietary adaptation. As Katharine Milton argues, “We know of few specific genetic adaptations to diet in our species”13. And even lactose tolerance isn’t that widespread across the human species.
Of course, I haven’t proved the Paleo hypothesis here. But I like to think I’ve established that it has a basic scientific plausibility that’s robust to Mr Angry’s objections. Note that it doesn’t depend on any notion that the Palaeolithic was some kind of ‘golden age’, or on a view that evolution creates one perfect being at a single point in time which is then impervious to change. It may turn out to be empirically wrong. But, for his part, Mr Angry furnishes no evidence to suggest that it is.
So why does he go to such lengths to ridicule it, employing such exemplarily bad science along the way? I think it’s because he’s less interested in critiquing bad science per se than in purveying a broader cultural argument. The milder form of this argument is that we shouldn’t get too hung up on our food choices or use them as status symbols. The essential message is: everything in moderation, enjoy life as you go, inject a bit of rationality into your thought and don’t point the finger of blame too much at yourself or other people. My feeling is that humans aren’t that good at rationality and incline quite naturally to symbolic thought, especially with culturally powerful things like food, and to games of status and blame. So I think Mr A has quite a battle on his hands to realise his vision – maybe that’s why he’s so angry. Sir, the angry farmer feels your pain. As a supporter of various lost causes myself, I’m not inclined to be too critical of this mild form of the argument, which strikes me as quite sensible.
But as the book wears on, the argument turns into something much more strident, totalising and, ultimately, pretty weird. Here are a few quotations:
“It is not enough to tackle dietary myths in isolation, attacking each one with competing evidence-based messages. In order to sell sensible, truthful messages, scientific truth itself needs to be made into an idea that sticks”
“To question science is to ignore everything it has done for man, to overlook the astounding progress of the last few hundred years”
“Processed convenience food has set women free, and every time we criticize convenience choices, we are showing our desire to drag women’s bodies and minds away from the workplace and back into the kitchen”
“I will always decry anyone who makes wild insinuations” …. “every society that has ever existed would eagerly swap their lives with someone living in the developed world today”
Here, ‘science’ as a form of rational, critical inquiry is turning into something else – a cultural or ideological proposition that contemporary ‘developed’ society is uniquely desirable and liberatory as a result of the inherent truthfulness of its science, which is now reconfigured in the argument as a unified repository of the good, something that must not be criticised for fear of falling into error. In other words, ‘science’ in this strand of Mr Angry’s presentation has assumed the mantle of religion or the revealed truth of God’s word. My shorthand term for this way of thinking about science is an uppercase SCIENCE, and it has precious little to do with science as a form of critical inquiry. Others refer to it as the ideology of scientism.
And this is all eerily familiar, no? The vaunting of contemporary ‘developed’ society against the inferiority of all other human societies. The religious style of elevating a particular truth claim – SCIENCE – over the putatively inferior, superstitious and relativist claims of its critics. The invocation of an oppressed category of people – in Mr Angry’s case, usually women – as uniquely liberated by the superior qualities of the culture in question, thereby positioning its critics as pariahs, in this case as misogynists. Oh, we’ve been here before – whether it’s diet, golden rice, nuclear power, urbanisation, ‘scientific agriculture’, or simply ‘progress’, the ideology of ecomodernism spreads its slimy tentacles ever wider. It always stakes a claim to speak up for the oppressed, for decency, and for progress, and against false idols like romanticism and relativism. And it’s always struck me as essentially religious in form – never more clearly than in Mr Angry’s exposition. Consider his comment:
“Poor dietary choices do not occur when people are driven by hedonistic pleasure, they occur when people eat without thought, and that will never happen if we engage with and truly love the food we eat”.
To me, this counter-Puritanism looks indistinguishable from the kind of unscientific mumbo-jumbo that Mr Angry spends so much time trying to debunk in his book. You could just as easily, and just as incorrectly, say that you’ll never get lung cancer if you smoke for hedonistic pleasure and truly love the tobacco you puff. As in Raj Patel’s fine book Stuffed and Starved, I think the truth is that we’ve ‘scientifically’ engineered our way to a global diet in which too many people get too much ‘feast food’ (typically the poorer people in the richer countries) and too many people get too little food at all (typically the poorer people in the poorer countries).
Ah well, I like to think I’ve written enough about ecomodernism in the past and have acquired a sufficiently like-minded and discerning readership on this blog not to labour the point of what, to use one of Mr A’s own favoured words, utter dumbfuckery his claims about hedonistic eating or the trans-historical desirability of contemporary ‘developed’ society are. So I’d just like to conclude with a few further thoughts about ‘science’.
At one point in his book, Mr Angry quotes from a speech by John F. Kennedy about the US moon programme in which the president said “space science, like nuclear science and all technology has no conscience of its own. Whether it will become a force for good or ill depends on man”. And yet there is no sense of this same ambivalence, of cultural contradictions and trade-offs, of paths closed off as new ones open up, in his own thinking about science, which he’s content to describe simply as “the greatest force for progress that there has ever been”. Well, off the top of my head, here are five great anti-‘progressive’ forces in the contemporary world which have all emerged as a result of the progress of science:
- anthropogenic climate change
- thermonuclear weapons
- accelerated biodiversity loss
- eutrophication of rivers and oceans
- loss of antibiotic efficacy through prophylactic agricultural use
My guess is that all of them have the potential to imperil human lives at a level orders of magnitude beyond that caused by Gwyneth Paltrow’s half-arsed dietary advice or the Gerson therapy and other dodgy ideas of the kind excoriated by Mr Angry, precisely because of the efficacy of the scientific method in combination with the vastly transformative nature of the capitalist economy. And if one had to choose the single greatest threat to humanity in contemporary society caused by the refusal to heed scientific opinion, it would surely have to be climate change, something that Mr Angry doesn’t mention once. And, seriously, which science-denier is the greater threat – Ms. Paltrow or JFK’s unsurpassably idiotic successor in current occupation of the White House? Ah well, I suppose just because we face major existential threats as a result of our science, there’s no reason to avoid writing books about the minor existential threats we face as a result of our non-science. But I don’t think these should be built up into a closed ideological defence of SCIENCE as an ideology of modernity and inherent progress. Despite the rather toxic debate we’ve got into recently concerning the status of experts in the wake of Michael Gove and Charlie Gard, this doesn’t seem a great historical moment to be extolling scientific progress, the cult of the expert and ‘development’ as virtues. In fact, I think books like Mr Angry’s are part of the problem. Which makes me kind of…angry.
- The Angry Chef. 2017. Bad Science and the Truth About Healthy Eating. OneWorld.
- Cordain, Loren. 2002. The Paleo Diet. John Wiley & Sons.
- The Angry Chef, op cit. I read the book on an e-reader and regrettably I have no idea how to give page references.
- eg. Kuipers, Remko et al. 2012. A multidisciplinary reconstruction of Palaeolithic nutrition that holds promise for the prevention and treatment of diseases of civilisation. Nutrition Research Reviews 25: 96-129; Lieberman, Leslie. 2003. Dietary, evolutionary and modernizing influences on the prevalence of Type 2 diabetes. Annual Review of Nutrition 23: 345-77; Lindeberg, Staffan. 2012. Paleolithic diets as a model for prevention and treatment of western disease. American Journal of Human Biology 24: 110-5; Milton, Katharine. 2000. Hunter-gatherer diets – a different perspective. The American Journal of Clinical Nutrition 71, 3: 665-7.
- Hardy, Karen et al. 2015. The importance of dietary carbohydrate in human evolution. The Quarterly Review of Biology. 90, 3: 251-68.
- Milton, op cit.
- Savard, Manon et al. The role of wild grasses in subsistence and sedentism. World Archaeology 38, 2: 179-96.
- Rose, Geoffrey. 1993. The Strategy of Preventive Medicine. Oxford University Press.
- Milton, op cit.
- Savard et al, op cit.
- Zimmet, Paul. 1992. Challenges in diabetes epidemiology – from west to the rest. Diabetes Care 15, 2: 232-52.
- Milton, op cit.