Monday, January 23, 2017

Nutrition Science

Nutrition science lives under a curse.  A never-ending parade of quacks and hucksters appear on the scene with miracle diets and theories that reveal the secret truths that mainstream nutrition has been trying to hide.  One of the more prominent hucksters is Gary Taubes, a free-lance journalist who has built a career by challenging the established recommendations on first salt, then fat, and now sugar.  Taubes' is actually a very successful huckster and has been able to garner space in important journals - including Science - and newspaper - like the New York Times.  His first campaign - revealing the hidden truth that excess salt consumption is unrelated to hypertension - seems have been put aside while he concentrates on the role of fat and sugar in obesity.   He essence of his argument is that calorie-for-calorie sugar consumption, through its effect on insulin, results in a larger contribution to body fat that fat or protein.  He summarized his basic argument in this article in the NY Times last week -

Motivated by a recent editorial in Nature, arguing that scientists must try to speak out in the public discourse, I wrote a "Letter to the Editor" which, alas, the NY Times chose not to publish.   But on our blog we can even publish some news that the TImes feels is not fit to print - here

I might add, at the moment in the insulin-sugar hypothesis has been disproven through feeding experiments (3).

Gary Taubes has made a journalistic career by taking contrarian stands against the “received wisdom” of nutrition science.   He has successively argued that the field has it all wrong on dietary saturated fat, salt and – most recently - sugar (NYT, Sunday, January 15).   I appreciate that, in order to be heard, journalists must stake out a position that will pique the public’s interest.  However, his voice has added nothing but noise and confusion to the public discourse on nutrition and health.  Both his key points in the recent opinion piece are wrong.  While our understanding of the role of nutrition in heart disease has advanced in the last several decades, the diet-heart theory is alive and well.  One set of key facts should make any reader skeptical of Taubes’ claims to the contrary.  Since the peak of the heart disease epidemic in the 1960’s mortality rates have dropped 80%, intake of saturated fat (mainly dairy) has fallen in parallel, and serum cholesterols have dropped about 10% (1); of course less smoking, better control of blood pressure and other medical therapies have contributed (1).  Meanwhile intake of sugar has increased 30% (2).  Control of heart disease has arguably been the most important achievement in public health in the US in the last 50 years and nutrition science played a key role.  Likewise, Taubes’ reiterates the canard that sugar somehow does not abide by the rule that “a calorie is a calorie”.  Since Taubes freely admits there is no evidence to support his claim, and definitive evidence to the contrary, one wonders why we should be interested in his opinion.

1. Ford et al. Explaining the decrease in coronary heart disease, 1980 – 2000.  New Engl J Med June 7, 2007.
3.    Hall KC. A review of the carbohydrate–insulin model of obesity
European Journal of Clinical Nutrition advance online publication 11 January 2017; doi: 10.1038/ejcn.2016.260

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