Monthly Archives: January 2011

Unhealthful News 24 – Trying hard to avoid stooping to the phrase "food fight"

The major American public health policy story right now is Walmart announcing, with a publicity boost and endorsement from the President’s wife (making it something with a whiff of official government policy, but not really such), a plan to push healthier food.  Reports about it range from the mainstream media reports (e.g., this one) where numerous reporters performed their stenography duties and reported that this must be a good thing because those announcing it say it is good to extremely skeptical critiques (e.g., this good one from an old friend of mine which links to others).  The plan includes reducing salt and sugar in Walmart store brands, pressuring their suppliers to do the same, and lowering the price of produce where they are a major source of it, implementing this all sometime over the next five years.

Debates about this plan involve questions of whether this is an important initiative or too little, a great use of the first-family’s bully pulpit or an inappropriate support by a government for a weak corporation-specific plan, a bold private move to fill in a social policy gap or preemptive weak action to avoid more useful regulation, and from a different direction, whether any corporate or government intervention is unreasonable interference with what is ultimately an individual choice.

I will bet that this issue annoys those who cling to the myth that there are no such things as good and bad foods.  While there is no bright line between good and bad, and quantities often matter more than items for overweight, we obviously can distinguish broccoli from cola on a healthy-unhealthy spectrum.  The “no bad foods” myth – which traces largely to the U.S. Department of Agriculture’s rhetoric, USDA being a dominant source of nutrition advice, but also a marketing agency for American-made food products (all food products) – is often embraced by the same people who like the idea of markets solving our problems.  So it is amusing watching them decide whether private efforts are good even when they are grounded in the good-vs-bad food message.

My contribution to the discussion today does not involve any conclusions about whether the new initiative is a good thing.  I am just going to clarify two issues that muddle the debate about the topic.

The arguments that have been written about this often focus on the question of whether health problems from food choice (overweight, inadequate micronutrients) are the fault of public policy, corporate decisions, or individual choice.  The answer is that all of these cause poor food choice.  Indeed, they mostly cause it via a particular causal pathway, wherein public policy affects corporate actions, and those actions affect individual choices, and the individual choices cause nutrition problems.  Of course, there are other paths – e.g., public policy directly affects individual choice via education – but this linear pathway is responsible for a lot.  As just one example, farm subsidies and free market rules that treat food little different from other goods cause companies to aggressively market junk food, and that marketing persuades people to make unhealthy choices.  Of course, some individuals still choose good foods despite the marketing and some companies escape the allure of cheap corn, so the upstream influences are not sufficient causes.  That is, they do not make the outcome happen all by themselves, regardless of everything else.  Often when someone claims something is not a cause of some outcome, they are really trying to say that it is not a sufficient cause.  So it is simply false to say “it is not the agricultural subsidies that cause companies to market junk food so aggressively, it is the fact that of shareholders are considered to be the only important stakeholders”; it is true that capitalism creates the profit motive, but the subsidies create the huge opportunity to profit from particular actions, so they are both the cause.

Sorting out all the apparently contradictory arguments is simply a matter of ignoring it when someone says “it is caused by X, not Y” and realizing that whenever someone says it is caused by government, corporations, or individuals they are right.  Everything always has multiple causes.  (They do not always follow a pathway like this, sometimes X and Y both cause something independently of each other.)

Once we get past the erroneous language about what is the cause of this problem, we run into the more legitimate language about what is the right spot in the causal pathway at which to intervene.  Educate consumers?  Encourage companies like Walmart to expand the supply of vegetables?  Impose rules like Los Angeles’s ban on new fast food restaurants?  Buried in this normative language is a confusion between what would have a desired effect and what is proper to do.  The first is a scientific question that is simply about predicting or empirically measuring consequences.  The second invokes ethical claims about paternalism, freedom, protecting the weak, and what is the public interest.  Of course, everyone can agree on the answers to the empirical scientific questions and then we can debate the ethical questions, informed by knowledge of what a particular intervention will actually do.

Ha! just kidding.  That is what should happen, of course.  But this being public health, there is no shortage of people with a particular political agenda distorting the science to show that their preferred approach is most effective.  There is a lot of dishonesty about true motives in this business – no one ever seems to say, “I do not much care what is most effective at improving diets, because I believe that the proper intervention is….” (Not to pick on those interested in diet – the same is true for most policies that involve people’s behavior.)  Those who want to blame corporate behavior embrace studies that show that kids are literally captivated (and by “literally” I mean literally, unlike most uses of that word) by Happy Meal and cereal advertising.  Those who favor education and individual choice point to people like me who have periodically lived in poor neighborhoods but have always eaten fairly healthfully because I knew how to do it.  Such points are somewhat accurate, but also overly simplistic and so misleading.  Parents do not have to surrender to kids’ wishes, the libertarians point out, but it is also true that people who have periods of being financially poor but who are well-educated are not very similar to most poor people in terms of personal empowerment (though such examples are also used to create the myth of American economic mobility – just because my income has shifted by more than 60 percentage points within the population distribution quite a few times in my life does not mean that America has high income mobility, or that when my income is low I am vulnerable to fast food marketing).

Anyway, to summarize:  Oversimplification of causal pathways is a tactic that is often used to elevate one particular intervention over other options; by declaring that something has one particular cause you can create the illusion that all interventions must start there.  Beware of statements about what we “should” do which muddle claims of “this would work better than alternatives” with “this is the morally proper way to do things”.  Do not trust news reporters’ “objective” reporting of “the” “facts” about deals between the government and corporations (be it subsidizing Wall Street or Walmart’s new line of low-salt kale chips) – governments lie, and so do corporations, but you will not be able to determine that if you only read what they dictate to the mainstream media. 

As for food politics, I am guessing that some particular sub-faction in this fight is honest about what the research shows overall, and I would tend to guess it is those who believe that pursuit of corporate profits is not optimal for nutrition but is better than not having a free market, and who believe in intervention but recognize that government intervention frequently hurts the public.  But I am not completely sure, even with the expertise I have, and would welcome anyone who says “read this and you will be convinced” (so long as “this” is not just a monologue of that does not even acknowledge there are opposing claims and counts on people just believing what they are told).  Even when you are right and backed by overwhelming empirical and ethical arguments, it is tough to make this this clear to people who are interested, well-read, and even technically skilled, and who want to understand which arguments are genuinely stronger, but are not expert in your particular political fight.  I am willing to be your test subject if you are willing to try to show me how it is done.

Unhealthful News 23 – Thou shall not enjoy being healthier

I will continue my practice of making Sunday posts a little different.  For this sabbath, two observations about the religious sides of public health.

I watched a few documentaries about beer brewing over the last few days, and decided to look for a health news story about beer.  WebMD favored my search with this story, which is currently on their front page, though there is nothing new in it.  What is special about the story is that it is called “The Truth About Beer” and, much to my surprise, it was almost the truth about beer.  Credit is shared between the author, Kathleen M. Zelman, and the researcher who she seemed to get most of her information from, Eric Rimm, who has been writing about this topic since I was in school.

Here was the best part:

It might seem unlikely, but beer (just like any wine, spirits, or other alcohol), when consumed in moderate amounts, has health benefits.

I hope the anti-alcohol disinformation has not been so effective that this actually still seems unlikely to most readers, but at least the message was accurate, which it usually is not.  For some reason, a myth persists that red wine, alone among alcoholic beverages, reduces heart attack risk and has other benefits, but there is no benefit from other drinks.  The evidence that all sources of alcohol have similar effects been clear for decades.  There was originally a hypothesis, ages ago, that the French Paradox (the fact that the French have better cardiovascular health than would have been predicted from naive models from many decades ago that over-emphasized the badness of dietary fats) might be explained by a benefit from red wine.  Red wine indeed turned out to be beneficial, but no more so then the more plebeian brown liquids that most of us prefer.

I said “for some reason”, but I suppose the persistence of the myth is neither a mystery nor an accident.  Similar to the myth that all tobacco/nicotine use causes large health risks, the myth about red wine is used by moralizing activists, who pretend to be motivated by their health “sciencey” claims but are really using the language of science to support their purification campaigns without admitting their political motives.  In this case, studies of isoflavones and such, and biased reviews of the data that cherry-pick any statistics that favor wine over beer, are used to try to convince people that the benefits are from a few stray molecules left over from the grape skin, rather than the ethanol.  Since relatively few of the unwashed masses that these activists are trying to manipulate have red wine as their drink of choice, the activists can continue to pretend that almost all drinking is bad.

I really do think there is a class issue at work here, and it affects why this news story (which also waxes about the quality of current American brewing) admits the truth.  When I came of age, there were only 60 breweries operating in all of America, and 99.9% of what they produced was little more than cheap slightly-alcoholic bubbly water.  Most anyone reading about the benefits of alcohol for a decade and a half after that saw nothing but the red wine myth, and those of us who knew enough to know the science and that there was such a thing as good beer did our own brewing (I was pretty good at it) and research (I published one paper about this ages ago).  Eric Rimm has been communicating the same message contained in the WebMD story for at least 20 years.  But now, with more than 1000 craft breweries and dozens of fairly large high-quality operations in the U.S., people who would have been wine snobs a generation ago now drink fancy beer, so the health news is no longer entirely anti-beer. 

The article also points out that beer provides the health benefit of hydration because it contains plenty of “fluids”, by which they actually mean “water”; the other fluids in it – alcohol and carbon dioxide (fyi, the word “fluid”, despite its misuse by medics and health reporters, means “any liquid or gas”) – do not aid hydration.  This is a rare response to the myth that any drink that contains alcohol is magically dehydrating no matter how much water it contains.  Wine and undiluted liquor probably do increase your need for more water to rinse out your system, and certainly do not offer the hydration benefits of beer.  They also seem to have the downside of increasing the risk of oral cancer due to topical exposure to the concentrated alcohol, though this was not mentioned in the article.

The article has a few gaffes (e.g., the alcohol content of beers cannot rise to 40%, a level that is only possible – at least with any yeast that has been invented to date – via distilling; even Sam Adams’s Utopias only makes it up to the mid-20s).  But the biggest problem with even accurate summaries of the health effects is this:

Health experts don’t recommend that anyone start drinking beer, or any other alcoholic beverage, for health benefits.

One of my readers pointed this oddity in a Facebook post a couple of weeks ago.  Of course, as he noted, it can be easily explained by the moralizing.  It is perfectly acceptable to recommend a pharmaceutical that also has unfortunate side effects, but we cannot recommend something that people actually enjoy.  Doing so might ruin the reputation of public health.  (The moralizers probably actually think that, and they probably do not recognize the bitterly ironic truth of it.)

On a completely random and unrelated note, I ran across this from the Journal of Policy Practice and just had to post something about it:

Deconstructing Social Constructionist Theory in Tobacco Policy: The Case of the Less Hazardous Cigarette
Author: Michael S. Givela
Abstract: Scholars in tobacco control have utilized a social construction approach to test and explain tobacco control policy and advocacy. Some recent tobacco control policy research has contended that Philip Morris’s support of the U.S. Food and Drug Administration (FDA) regulation of tobacco (including purportedly reducing the harm of cigarettes) is to obtain the social construction goal of a socially responsible company. However, the primary motivation for Philip Morris’s support of proposed FDA regulation and harm reduction for cigarettes was to maintain the company’s market stability and profitability implemented by U.S. political process and institutions. In tandem with this, Philip Morris also sought political stability, a new company image, and federal preemption of conflicting and costly state requirements for harm reduction and tobacco ingredients. Social construction theory did not explain Philip Morris’s motivation for seeking FDA regulation of tobacco. Only by reducing tobacco industry markets and customer use will there be a significant reduction in tobacco consumption.

As my readers know, sometimes I am embarrassed to be associated with epidemiology or particular subfields.  But when things seem to be at their darkest, I can always look on the bright side and realize that no matter how bad the literature in my areas is, at least it is usually caused by researchers not understanding and making a hash of what is an inherently legitimate science.  It is not actually a parody of science.

I honestly could not stop laughing after reading that abstract out loud to someone.  Try it, it is fun.  It is like trying to recite the dialogue from Star Wars – until you try to say it out loud it is not obvious how funny it is.  (In fairness, having heard my blog posts being read out loud by my “editor”, what I write sounds pretty funny too, at least when read to the baby in a Winnie-the-Pooh storytime voice.)

It is interesting to see that last sentence of the abstract in something that is not standard anti-tobacco health science (or health pseudo-science); it is apparently a cross disciplinary part of anti-tobacco as a religion.  It obviously does not follow from the analysis.  Instead, it is a version of the mandatory “amen” that you have to attach to the end of any paper to maintain membership in the anti-tobacco activist congregation.   Still, it is a pretty funny version of the amen:  It says that reducing consumption depends on reducing sales and consumption.  I guess it is difficult to argue with that.

To add a little bit of substance to this analysis, I suspect this is an example of the Mythbusters fallacy that I explained in Unhealthful News 4.  Saying that “social construction theory” cannot explain PM’s behavior was based on looking at a particular possible interpretation of the theory and its implications.  I am quite confident that social construction theory can produce a just-so story to explain anything someone wants it to explain with it (read: it seems to be pretty much just made up on the fly).  Thus, declaring that it does not explain a particular action seems rather, well, convenient.  Of course, any serious analysis of PM’s actions in this matter would note that pretty much every one of the motives mentioned probably played some role, so the conclusion “their actions cannot be entirely explained by X” is undoubtedly true.

Still, I think my class-discrimination-based theory of public health disinformation about alcohol stands up pretty well as a sociologic theory.  So, I will conclude with:  Only by reducing the elite’s monopoly on information will we be able to increase the democratization of information. 

And seeing how it is now after 5:00pm somewhere, may I recommend that if you like a medium-hoppy amber that tends a little bit toward scotch ale, that you reduce your heart attack risk with Gordon Imperial Red from Oskar Blues Brewery in Colorado (which is SKU 8 19942 00008 1, not that I have one in my hand right now).  Also, if you have ever actually spent the three-figures per bottle price to try Sam Adams Utopias could you drop me a note and tell me how it was; I am really curious.

Unhealthful News 22 – I will continue to Countdown disgraces in the news

Today I decided to check MSNBC’s health news for a story, as a tribute to Keith Olbermann’s work there and to take a minuscule poke at MSNBC for driving him away.  I was rewarded with this story, right at the top of the page, about the “discovery” that eating a larger breakfast is not helpful for losing weight.  It is a great example of confused health reporting resulting from trying to hype nothing as well as what you might consider a surprise based on a few of my recent posts, putting faith in an observational study of a subject that can only be effectively studied with an experiment.

The article begins, “For years, dieters have been told that the way to lose weight was to start the day with a hearty breakfast.”  I cannot say that I study current leading weight loss advice, and I suppose that for any behavior relating to food or exercise, someone recommends it for weight loss.  But I am pretty sure that the advice about breakfast is merely to not skip it (because the backlash from feeling starved will drive you to eat more later), and sometimes a recommendation of protein and fat over carbohydrates.  Also there was some recent intriguing advice to exercise before you first eat in the morning.  But to just eat a lot?  It is not clear why anyone would think that is a good idea.  The reporter fashioned her story so that the exciting new conclusion was to eat something, but not a lot, which I suspect is exactly what most of the current advice says.

It is bad enough when news reports identify a current conventional wisdom, stating it like fact even though it is fairly uncertain, and then declare it to be overturned based on a single new study, ignoring flaws in the new study, to say nothing of the fact that scientific inference is not based on “whatever is newest is right” rule.  That is probably responsible for the majority of public confusion and annoyance with health reporting.  But it is even worse when the reporter just makes up a fake conventional wisdom and then claims to be reporting on the “news” that we “now” “know” something else to be true.

As for the study itself, it tells us almost nothing because of confounding.  Readers of this series will recall some posts where I criticize the naive notion that experiments on people (usually called RCTs: “randomized clinical/controlled trials”), where the researchers assign people to particular exposures, always provide better information about health effects than observational studies, where people choose or experience exposures as they would in everyday life.  As I noted at greater length before, RCTs eliminate systematic confounding but at the expense of creating a very artificial situation, with the odd sort of people who would volunteer to have an exposure assigned to them, exposures which may not represent a realistic range of what people actually experience, and forces people to do something they might never have chosen.  Figuring out whether the upside or downside matters more requires some scientific common sense.

If something is purely biological (rather than behavioral or psychological) and normally occurs in an artificial controlled setting, then most (not all) of the downsides go away.  This is why RCTs are good for comparing the effectiveness of medical procedures.  But if you are interested in the behavior of free-living people, the downsides become quite large.  That is why the vogue of doing RCTs and implying that they tell us whether smokers will switch to smokeless alternatives is just bad science.  What is of interest is whether many typical smokers can be informed or persuaded so they choose to switch, using mass communication, as a behavioral choice in their lives.  The RCTs start with the odd subgroup who are inclined to volunteer for a cessation intervention, educates them in a particular way, which may not be effective and is certainly not natural or based on normal educational methods.  Perhaps the results tell us a little bit about what we might really want to know, but they tell us far less than, say, observing the actual substitution choices made by would-be-smokers at the level of personal anecdote, to say nothing of systematic observational studies.  For somewhat different reasons that I noted in the previous posts, RCTs of how long to exclusively breastfeed also end up measuring something we do not really want to know. 

Back on the other side, though, are cases where the confounding is obviously such a huge problem that if it cannot be eliminated then we really cannot possibly hope to sort out the actual causal relationship.  This is the case with the study that triggered today’s news story.

I have colleagues who might suggest that – in the spirit of the cliche “how can you tell if X is lying?” “his lips are moving.” – you can tell if epidemiologic studies of diet and nutrition are junk science by observing that they are epidemiologic studies of diet and nutrition.  There is a lot to that – most of what is done in those areas is a complete joke.  The methods for measuring the exposure (i.e., what people eat), subjects keeping diaries of that information, have been shown to be terrible, and the statistical analyses are often – perhaps even usually – so bad as to be unethical.  But more specifically in this case, the observation was that when someone reported eating more for breakfast it was not associated with them reporting eating less for the rest of the day.  That is, whatever the extra food intake at breakfast, at the end of the day the intake is elevated above the average by about the extra breakfast calories.  But does this mean that eating more at breakfast does not cause a compensating reduction later in the day?  Absolutely not.  There is confounding, both across the population and across different days for the same person.  Some people just eat more than others, obviously, even among study subjects who are trying to lose weight.  They eat more for breakfast, and also a lot the rest of the day.  This effect can be controlled for in the study design, by using someone as his own comparison group (i.e., see if he eats less or more on a particular day, as a function of breakfast, compared to what he himself eats on average).  (There is also the more subtle problem of biased measurement error:  Someone who misreports what he ate for breakfast may also misreport about lunch that day, but I suspect I will have better examples of this point later.)

But though the interpersonal differences can be pretty well controlled, that just leads to another level of confounding that cannot be controlled.  Some days any given person eats more than on other days, due to activity, mood, opportunity, social pressure, simple swings in appetite, or whatever.  So if someone eats a large breakfast, he may do so for reasons that also cause him to eat more than he might otherwise the rest of the day.  So it might well be that eating more at breakfast causes someone to eat less than he would have the rest of the day, but this effect is swamped by whatever caused the eating of the big breakfast.  The claim is still not really plausible (it was never particularly plausible that eating more for breakfast would cause someone to eat less overall), but the point is that the study does not really inform us; there is a problem with confounding that is so bad that it renders the study useless.  So what would be a better way to address this question?  To assign the size of each person’s breakfast each day and see what else they eat – in other words, do an experiment.  Then how much someone eats for breakfast is unrelated to their activity, mood, etc. because it is random, and so the association, or the lack of association, cannot be explained by the obvious confounding.

Why is the artificiality of that not such a problem in this case?  Because what we are really interested in is not what results when people happen to choose to eat a big breakfast, but rather what would happen if they forced themselves to eat (or avoid) a big breakfast.  We want to know if it is a good tool to achieve a particular goal, just like we want to know that about a drug or surgical procedure.  Thus, using a method that works well for testing drugs and surgical procedures seems like a good idea.  We still have the problem that, since this is behavioral rather than biological, that people might react differently to being assigned a meal size as compared to forcing it upon themselves, so the RCT approach still has problems, but it is certainly better than completely fatal confounding.

I expect, however, that we are never going to see that trial.  The researchers might have tricked the MSNBC reporter into believing that this represented some important new knowledge, but I suspect no researcher would be interested enough in the question to do the RCT.  Rather, these dietary studies are almost always fishing expeditions, collecting a lot of data about hundreds of things and then sifting through it for associations that might be used to impress someone.  So, with the exception of the anti-tobacco extremists and a few other political actors, who are not really even scientists anymore, I will declare nutritional researchers, particularly the “health promotion” types and dietitians, to be today’s Worst Epidemiologists In The World.