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Chocolate and the Nobel Prize

Written by Jacob Schor, ND, FABNO, AANP Board Member - Chocolate has long been associated with affairs of the heart and gifts of chocolate are considered particularly appropriate for Valentine's Day. Medical writers first began alluding to an aphrodisiac effect from chocolate back in 1624. Joannes Rauch spoke of chocolate as a ‘violent inflamer of passions.' Richard Cadbury was the first to package chocolate into heart shaped boxes for Valentine's Day in 1861. Yet chocolate's association with the heart goes back much further, to the prehistory of chocolate in the Meso-American cultures. The Aztec words for heart and blood were synonymous with their word for chocolate. They drew pods of the cacao tree in the shape of hearts in early illustrations and chocolate drinks were interwoven in the rituals of human sacrifice.


I've written before about chocolates impact on cardiovascular health:

And about chocolate's effect on cognitive function:

The idea that chocolate improves cognitive function is where the excitement is these days, and also the fun. A series of articles and letters have been published in rather prestigious journals over the two years suggesting an association between a country's chocolate consumption and winning Nobel Prizes.

In October 2012, the New England Journal of Medicine published an article by Franz Messerli, , which suggested to readers that the flavonoids in chocolate preserve and protect cognitive function and that hypothetically this effect could be seen in whole populations as well, thus there might be a “… correlation between a country's level of chocolate consumption and it's population's cognitive function.” As no data compare cognitive function by nation, Dr. Messerli thought that the number of Nobel laureates per capita might serve “… as a surrogate end point reflecting the proportion with superior cognitive function and thereby give us some measure of the overall cognitive function of a given country.”

Using data from Wikipedia a graph was created of laureates per 10 million people on one axis plotted against per capita yearly chocolate consumption for 22 countries for which data was readily available. This yielded a nearly straight line, with Switzerland at the top of the slope and China at the bottom. Sweden was the only outlier, having won more Nobel prizes than might have been predicted based on chocolate consumption. Their per capita chocolate consumption was only 6.4 kilo per year, good for about 14 Nobel laureates, yet they had 32. This might be explained by “….some inherent patriotic bias when assessing the candidates for these awards….” If Sweden is eliminated from the analysis, the already close linear correlation (r=0.791) between chocolate and laureates increased to 0.862.

Writing an almost immediate response to Messerli for Scientific American, Ashutosh Jogalekar expressed his outrage at the simplistic nature of this chocolate study, “if only three rules of scientific deduction were inscribed on the doors of every university and research organization in the world, one of them should be that “correlation does not mean causation”. Conflating the two can lead you to believe, for instance, that storks deliver babies. ” The intensity of his rant suggests a corollary hypothesis, that deficiency of chocolate may hinder a person's sense of humor.

In December 2012, Manfred Kayser commented on the Messerli paper in the journal Investigative Genetics, “But can there indeed be a causal relationship between how much chocolate one eats and how extraordinary and groundbreaking one's scientific achievements are? We cannot know without further studies, and Messerli suggested a prospective randomized trial to be carried out. Notably, he also points out the reverse scenario that a high cognitive function may stimulate chocolate consumption. Typically with these chicken-or-egg scenarios it will be difficult to elucidate what exactly is going on until the effects of chocolate ingredients, such as flavanols but also others, on human cognitive function are tested more thoroughly, for instance by experiments designed to explore the putative effect more directly.”

In June 2013, Frank Dunstan, writing in Practical Neurology, pointed out what he considered an apparent weakness in the original paper, that the “… analysis, … was what epidemiologists call an ecological analysis. Data were aggregated by country, and so the results suggested that countries with high chocolate consumption have tended to produce many Nobel prize winners; crucially, however, we do not know what were the eating habits of the prize winners themselves. Ecological studies are generally regarded as hypothesis-generating; those of us who try to teach the basics of epidemiology to medical students warn them of possible dangers …” Just because people in a country eat a lot of chocolate doesn't necessarily mean that the scientists eat a lot of chocolate. This argument was countered a few weeks later by Golomb et al.

In July 2013 Beatrice Golomb et al informed the debate both by an article published in Archives of Internal Medicine and in a short letter published in Nature , both described her own study in which her research team “… surveyed 23 male winners of the Nobel prize in physics, chemistry, physiology or medicine, and economics. Ten (43%) reported eating chocolate more than twice a week, compared with only 25% of 237 well-educated age- and sex-matched controls…”

Also in June 2013, Loney and Nagelkerke suggested in the journal Evidence Based Medicine that lactose intolerance played a potential role in the association between chocolate and Nobel laureates, pointing out that countries with relatively few laureates, China and Japan, have very high rates of lactose intolerance. The lactase gene is located on chromosome 2; polymorphisms of this gene are linked to academic achievement.

While all of these articles have a certain tongue in cheek quality, they obviously do not prove cause and effect, they do bring attention to the link between the flavanols found in chocolates, green tea, red wine and some fruits with improvements in cognitive function. Perhaps while this is bad science, it is still entertaining.

Thus as Valentine's Day approaches, the smart thing to do, will be to select and purchase a bit more and a bit better chocolate than you need to for your special person. According to these researchers, doing so may result in an extra special prize.

References
Chocolate Consumption, Cognitive Function, and Nobel Laureates, Franz H. Messerli, M.D. N Engl J Med 2012; 367:1562-1564October 18, 2012DOI: 10.1056/NEJMon1211064 Full text

Investig Genet. 2012 Dec 11;3(1):26. doi: 10.1186/2041-2223-3-26.

Editors' pick: Christmas is coming - time for chocolate to get ready for yourNobel Prize. Kayser M. Free PMC Article

Pract Neurol. 2013 Jun;13(3):206-7. doi: 10.1136/practneurol-2013-000588. Nobel prizes, chocolate and milk: the statistical view. Dunstan F. Comment on Chocolate consumption, cognitive function, and Nobel laureates. [N Engl J Med. 2012]

Chocolate habits of Nobel prizewinners. Golomb BA, Brenner S, Chalfie M, Glashow SL, Glauber RJ, Hubel DH, Maskin ES, Greengard P, Gross DJ, Roberts R, Tonegawa S, Wilczek FA, Brown EM, Sejnowski TJ. Nature. 2013 Jul 25;499(7459):409. doi: 10.1038/499409a Nature. 2013 Jul 25;499(7459):409. doi: 10.1038/499409a. Full test

Behav Genet. 2006 Jan;36(1):56-64. Epub 2005 Dec 13. A linkage study of academic skills defined by the Queensland core skills test. Wainwright MA, Wright MJ, Luciano M, Montgomery GW, Geffen GM, Martin NG.

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