Features, Science / Tech

Science, Sin, and Paternalism

A new study, published in July by University College London, has apparently revealed that men (but not women) who consume a large amount of sugar are at higher risk of long term mental illness. The scientists who carried out the study used their press release to support the British government’s so-called “sugar tax” — a special levy due to be imposed on certain soft drinks in 2018. One author expressed dismay that a similar policy was not enacted in other European countries, while another added a jab at the “commercial forces” that “exploit” the gullible, weak-willed populace by selling us sugary drinks. The message is loud and clear: sugar is bad, government regulation is good, and now we have the science to prove it.

Although the study itself is available online, I am not qualified to provide a detailed critique of its methodology or conclusions. A cursory inspection suggests that it does at least look like science, and does not contain poetry, “performative autoethnography”, or any of the other gibberish that characterises the worthless vanity papers highlighted by @RealPeerReview on Twitter. In particular, the authors claim to have anticipated and ruled out the most obvious objection: that increased sugar consumption is a consequence, rather than a cause, of mental health issues. Therefore, for the sake of argument, I shall assume that the paper is methodologically sound, and does indeed provide strong evidence for a causal link between sugar consumption and long term depression.

But regardless of the paper’s validity, the ease with which the authors segue from an interesting scientific conclusion to enthusiastic applause for meddlesome, authoritarian government policy is troubling. The study did not prove that there needs to be a sugar tax, it merely suggested the existence of a link between sugar consumption and mental illness. Other factors claimed to improve mental health include physical exercise and social activity, but I have yet to hear of any proposal to introduce mandatory gym membership or a “no-friends tax” (perhaps these are planned for 2019). Furthermore, we already knew that eating too much sugar is unhealthy — this is why the sugar tax was announced in the first place — so the evidence from this paper doesn’t change anything. The fact that both lead authors used their results to promote nanny-state legislation makes one wonder whether they had an agenda other than objective scientific investigation.

The logic behind the sugar tax is that artificially inflating the price of sugary drinks will make people think twice about buying them, thereby encouraging a more healthy lifestyle. To support this policy requires a couple of significant assumptions. Firstly, that this sort of “sin tax” is actually effective at reducing sales of the supposedly sinful product. In the case of sugar, evidence for this effectiveness is slim at best. Other countries have tried similar policies, and while there is some indication that they do produce an immediate drop in consumption, the effect is small (a single figure percentage), possibly temporary, and thus far not linked to any noticeable improvement in public health. As politicians tend to double down on bad ideas, rather than abandon them, the most likely outcome is that the levy will be continually increased — as the taxes on tobacco have been for decades — until the policy becomes almost indistinguishable from outright prohibition.

Then there are the political assumptions: that the government has a right to regulate our behaviour for the good of our own health, and that flat-rate sin taxes, which invariably hit the poor much harder than the rich, are a morally justifiable policy. These are not propositions for which any notion of “evidence” can be discussed, because they are not factual in nature. They are purely political judgements, about the role and responsibilities of government and its relationship to the individual. You may believe that a tax on soft drinks is a good idea, or you may not. I certainly don’t. But one way or the other, these are subjective, personal views based on our own particular principles. They have absolutely nothing to do with science, even if a scientist uses a scientific paper as a platform to promote them.

A famous problem in philosophy, articulated by David Hume in the 18th century, concerns the “is-ought gap”. This is the separation between two fundamentally different kinds of statements: those which simply describe the world, such as “the sun is hot”, and those which express a prescriptive moral viewpoint, such as “people ought not to steal”. What Hume realised is that there is no easy way to cross the gap. It is logically impossible to reach a conclusion about how people ought to behave purely from factual statements about how the world is. But this is exactly what the authors of the UCL paper are doing. From a newly-discovered scientific fact — sugar consumption may increase the risk of depression (in men) — they immediately declare that the government should be imposing new taxes and trying to control our diet.

None of this is intended to suggest that anyone should be censored. Scientists, regardless of their funding source, are free citizens who should be able to speak their mind like everyone else. Nor would it be appropriate to accuse the authors of the UCL study of being government mouthpieces; there is no evidence to suggest that their statements are anything other than genuinely-held personal opinions. Indeed, the soft drinks levy was actually demanded (and originally rejected) in a public petition that attracted well over a hundred thousand signatures.

But we should be quite clear: this is a political decision, made by ministers who clearly believe that the relationship between citizen and state should be one of paternalistic authority. An idea such as this needs to be debated and defended in the public sphere, not dressed up as some kind of objective scientific truth that the rest of us should accept without question.

Filed under: Features, Science / Tech


Matthew Mott is a writer and photographer with a background in technology, based in the UK. He can be found on Gab.ai as @InfiniteDissent


  1. John Dickinson says

    This article’s author is exposing his rancour by using trite pejoratives (“nanny-state”, “sin tax”, “meddlesome, authoritarian government policy”) and weak, sarcastic analogy (“I have yet to hear of any proposal to introduce mandatory gym membership or a ‘no-friends’” tax”).

    But let me clarify some misrepresentation.

    The article claims that, in the press release “[one of the authors] added a jab at the ‘commercial forces’ that ‘exploit’ the gullible”. What was actually said was “The physical and mental health of British people deserves some protection from the commercial forces which exploit the human ‘sweet tooth’”. Not unreasonable.

    He claims that, in the press release “One author expressed dismay that a similar policy was not enacted in other European countries”. What was actually said was “There is increasing evidence for the physical damage sugar has on our health. Our work suggests an additional mental health effect. This further supports the evidence for policy action such as the new sugar levy in the UK, but this is not addressed in many other European countries”. Later in this article Mott states “Furthermore, we already knew that eating too much sugar is unhealthy — this is why the sugar tax was announced in the first place — so the evidence from this paper doesn’t change anything”, firstly ignoring the fact that the study’s authors state the already-known health detriments, then implying that evidence for additional health detriments doesn’t add weight.

    I suggest that both of the above statements by the study’s authors are not the egregious politicisation of their work that the author is implying. Note that the department from which this paper came is the UCL Institute of Epidemiology and *Public Health*. I’d be extremely surprised if this department didn’t have opinions on public health policy. The article’s author then says “makes one wonder whether they had an agenda other than objective scientific investigation”. Well, yes, public health. But the insinuation is that they cannot be trusted to do the science. Firstly, if it’s good science then it would be validated as such by the peer review. Science Reports is a publication of Nature. A stated aim is “Thorough peer review with a focus on scientific validity — rather than significance or impact.” i.e. It has the reputation of Nature to uphold, but providing a journal that doesn’t have the requirement of the significance or impact required by very prominent Nature journals. Secondly, all scientist will have their pet hypotheses. It is the scientific process that discovers whether they are true and weeds out bias. There are more or less reasons to trust the science has been well done. One main corrupting influence is money, and I sense that the article’s author is trying to discredit the authors with some of that influence’s polluting stink.

    Now for some push back on the trite pejoratives and weak, sarcastic analogy.

    “nanny-state” and “sin tax”: Ugh. There’s a rabbit hole one doesn’t want to go down. Let me just make this specific argument. Sugary drinks keep better than other drinks that may be more healthy (e.g. a fresh, cloudy apple juice). This is one reason the sugary drinks are cheap. If a tax can push folk to drink less of that and more fresh juice then there is an additional economy of scale pressure towards cheaper juice. Hooray (not just for me, but for those who are struggling to afford better food). (Please don’t argue that a juice subsidy would, in that case, be better; I agree, but it’s not going to happen).

    “meddlesome, authoritarian government policy”. The point of government is to meddle, with the authority it is given. If you want to make an argument against government interference, make the argument on specifics.

    Mandatory gym membership? Don’t be ridiculous. The analogy would be spending money (tax) to make exercise easier or more fun: cycle lanes, better parks, council sports centres. It already happens, and it is … good.

    No-friends tax. I’ve already used the phrase “Don’t be ridiculous”. This is more deserving and speaks for itself as something that undermines any argument being made in this article.

    • Bartlomiej says

      Well, I think it is overly optimistic to consider ‘no-friend tax’ as something out of this world. For example, in my country there actually existed a ‘tax on unmarried singles’ (it was called ‘bykowe’) – and I am not talking here about middle ages but 1970s. Twenty years ago the very idea of European Union banning light-bulbs would be considered ridiculous. Ten years ago the idea that London would ban the production of non-electric vehicles would be considered ridiculous. But such things are actually happening for the sake of fighting climate change or promoting public health and so on…
      The other problem with taxing the ‘unhealthy’ behaviour is the fact, that such taxes are aimed to decrease the costs of the healthcare in the short to medium run, but are generating indirect costs in the long run. Heavy eaters or smokers are not the ones who generate most costs for the modern healthcare – their premature deaths are in fact the blessing both for the public healthcare and social security. Taking this into account, the act of imposing additional taxes on these people is rather unjust (they are already taxed by, for example, the way the public pension system calculate retirement benefits).

      • John Dickinson says


        Your bykowe was introduced by the communist government (in 1946) (and it’s not a “friend tax”). But the point is taken. However, my point was that a “friend tax” is not “next” after a sugary drink tax, as if they were anywhere near alike.

        As for the banning (phasing out) of (incandescent) light bulbs or non-electric cars, the reason that such bans might have been unimaginable is that the circumstances where such bans make sense were unimaginable. An incandescent light bulb ban makes sense considering the fantastically easy, and necessary, due to climate change, reduction in power consumption by the wonderful LED tech. A (planned, future) banning of non-electric cars in cities makes sense in the light of the unanticipated pollution due to fossil fuel cars and the impressive strides made in electric car practicality. This is exactly the kind of “meddling” that government should do. Otherwise we live a tragedy of the commons (and would currently be living if governments hadn’t introduced emissions regulation that really did accelerate the massive reduction in harmful emissions). The cheap ubiquity of sugary drink is another sort of tragedy of the commons; the cheapness makes some folk buy it over other stuff, which makes it cheaper still, and the lower demanded better stuff is now out of reach of the poorest.

        And the objective of better health is not to reduce healthcare costs. It’s better health.

  2. I agree thoroughly with John Dickinson’s comment above and also would direct people to actually read the link the author of the article cites as “slim evidence” that sugar taxes work to see that even an oppositional argument has to admit several points of success in these programs. There are real criticisms of the current way we implement them, expressed in a fairly accessible way here (http://www.nejm.org/doi/full/10.1056/NEJMhpr0905723#t=article) while also providing the economic theory that underlies the efficiency of these taxes.

  3. Josh says

    I think the biggest problem I have with the conclusion here is the fact that people always seem to “know” which way the correlation goes. Who’s to say that sugar “causes” or even “contributes” to depression and not the other way around? Frankly, it seems much more likely to me that depressed men are more likely to seek the quick hit of pleasure that sugar provides.

    Regardless, drawing any conclusions from the correlation is just plain silly.

    • John Dickinson says


      The abstract of the study states “[The] aim of this study was to … and to examine the role of reverse causation (influence of mood on intake) as potential explanation for the observed linkage” and “In prospective analyses, men in the highest tertile of sugar intake from sweet food/beverages had a 23% increased odds of incident CMD after 5 years” and “Neither CMD [common mental disorder] nor depression predicted intake changes.” i.e. they are very aware of the problem of cause vs correlation (obviously, they’re scientists) and they included work to find the direction of the casual arrow; it’s pointing from sugar intake to CMD and depression.

  4. Ethan Zwirn says

    Coming from the comment sections of other publications, it is refreshing to find someone as thoughtful (and yes, I admit, as in line with my views) as John Dickinson. The government taxes products in the interest of public health. Cigarettes, anyone?

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