14 April 2011

Unhealthful News 104 - Even when you are right, not all the science supports your point

Two of my friends, Chris Snowdon and Jeff Stier, published posts in the last day that give examples of how difficult it is for those of us (I include myself) who analyze science but also have a worldly preference about what we are studying to separate the two.  Sometimes we are right about a worldly conclusion, and we are sure we are right, but that does not mean that every bit of science on the topic supports our position.  Snowdon provides a nice analysis of people failing to recognize that while I would contend that Stier stumbles into the trap a bit (sorry, Jeff!).

Snowdon's post is about a new study that concludes that alcohol consumption, even at moderate levels, causes cancer risk, and that a fairly high portion of all cancer is alcohol-attributable.  It seems almost certain that the study substantially overestimated the effects due to uncontrolled confounding, but what Snowdon found more interesting (and I agree) were the arguments made by those who did not like the result.  Commentators who might have embraced bad news about risks from heavy drinking, to say nothing of nicotine use, looked for a reason to dismiss this result.  Not understanding how to comment on uncontrolled confounding, they resorted to arguments Snowdon described as "very reminiscent of the weak arguments made in the 20th century against the smoking/lung cancer link."

I will not try to summarize the results or the weak arguments against them – you can find all that in the original post.  The key point is that there are good defenses for moderate drinking, such as the beneficial effect on cardiovascular health and, more important for most people, it is enjoyable.  Thus, the conclusion in the article is, like most policy recommendations made in public health articles, completely unsupported by the evidence and is purely a political statement: "This strongly underlines the necessity to continue and to increase efforts to reduce alcohol consumption in Europe, both on the individual and the population level."  It would be bad enough if they said "value of", but "necessity to" – really?  I would ask how drunk the authors were when they wrote that, but I am guessing they have no such excuse for their indefensible claim.  But the response to this claim should not be "moderate drinking is good, and therefore your evidence that it has a downside must be wrong!", but rather "moderate drinking is good and remains so, though we should consider this downside when making that assessment."

Stier's post is a nice analysis of how current American governments' public health policies continue to remove people's liberties even though the current "regulatory czar" in Obama's administration is the champion of "libertarian paternalism", Cass Sunstein.  In fairness to Sunstein, coauthor of the book Nudge which proposes ways to steer people in what we think are better directions without denying them the option of making thoughtful choices to the contrary, I doubt he has all that much influence.  His writings certainly makes a good case that many current policies are the wrong way to do things, as Stier nicely points out.

However, I suspect Sunstein would be fine with one thing that Stier seems to oppose: requiring chain restaurants to post calorie counts for their foods.  This takes no liberties away from consumer, merely suggesting to them that what they are ordering contains more energy than they thought (usually the case).  I believe that Stier's main concern is that activists decided that information did not have all the effects they wanted, so their reaction was to propose something less voluntary.  That is certainly a valid criticism of the policy makers, if not the policy.  It is disingenuous, indeed dishonest, to try to persuade someone of the wisdom of a particular choice, but then try to force their choice when the free choice is not what you want.  But this dishonesty is not an argument to end a perfectly valid provision of information. 

Unfortunately, Stier seems to be arguing that since the information is wrapped up in a constellation of bad policies, we should stop requiring it.  (To some extent he seems to also be arguing it did not work, based on one study, but as I pointed out in UN48, that widely cited study did not actually provide such evidence – it just fit political biases (on both sides) too well.  But that is separate from my current point.)  He makes a convincing case that there is a growing body of restrictions on food choices that are illiberal and that have no scientific support (see the post for details – it is definitely worth reading).  But that does not mean that all new regulations are illiberal or that every criticism of them is correct.  Just as it is possible to say "maybe moderate drinking causes some cancer, but that does not support blanket anti-drinking measures", it is possible to say "calorie labeling seems to be a reasonable requirement with no serious downside, but that in no way justifies forcing people to behave a particular way when they do not respond 'correctly' to the information."  I invite Jeff to speak up in the comment section if I have missed an argument against calorie labeling, but "American has gone completely nuts about food regulation", while a defensible point, does not seem to be an argument against this regulation.

Bottom line:  Not every argument made in favor of a good idea is a good argument.  Not every attack on a good or valid position is without merit.

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