Key Terms Calorie A unit of energy commonly used on food packaging to describe how much energy is obtained through the consumption of a specific food product. Hormones Signalling mole- cules that are used for communication between various organs in the body for physiological regulation over processes such as metabolism. E very day, we are bombarded with advertisements for new weight loss diets, supplements, and exercise routines. The vast majority of us spend our entire lives struggling to maintain a weight that is healthy or desirable. There are cer- tainly many people that are over-eating or under-exercising for their caloric
In science it is easy to get carried away with over-interpretation of data; one sees flowers where there aren’t any! This serious flaw is highlighted in the recent 2012 edition of the New England Journal of Medicine; Franz Messerli, a well published cardiologist at Columbia University noted a strong correlation between the consumption of dark chocolate and winning the Nobel Prize. Indeed, the author goes on to recommend increased consumption of the dark substance so that cognition is improved in the overall population and more humorously, the chances of winning the Nobel Prize are greatly enhanced.
The author shows a graph of 23 countries along with their chocolate intake, and the number of Nobel Prizes won per ten million people. Countries with the greatest intake show the most Nobel Prizes (Switzerland, Austria, Denmark and Norway) and, where there is the least intake (Japan, China, Greece, Italy, Brazil) the lowest wins of the famed prize.
It is true that dark chocolate is loaded with flavonoids; a large class of compounds abundant in the plant kingdom and associated with improvement of a variety of health issues. Increased consumption of flavonoids and particularly a subclass called flavonols which are present in cocoa, have received increased scrutiny due to their benefits for the cardiovascular system including; lowering blood pressure, improving the health of blood vessels (improving endothelial function), maintaining vessel elasticity. Flavonols are also linked to improving cognition and reducing dementia especially in seniors.
The mechanism of action of flavonols may be due to their antioxidant effects thereby quenching the highly reactive free radicals which are being continually generated in the body. There is also a direct vasodilatory effect on blood vessels.
However, does chocolate deliver sufficient amount of flavonols for clinical efficacy? One would have to consume large quantities of chocolate to achieve any measurable results. Plus, the effects of other ingredients in chocolate including dairy, sugar, emulsifiers, binding agents, fats etc. may have an opposite effect.
However, as Maurage and colleagues report in the recent Journal of Nutrition regarding the conclusions drawn by Messerli, they “go way beyond the data and thus must be questioned on methodological, statistical and logical grounds.”
The first objection is on methodological grounds since the data used an averaged chocolate consumption of each country and NOT the actual consumption by the Nobel Prize winners (I don’t think such data is available). This poses a problem, namely one uses group behaviour to draw conclusions on individual behaviour.
Second, the correlation of chocolate consumption is for 2 years, while the Nobel Prize winners ‘studied’ were chosen from the last 100 years! The two variables/factors aren’t monitored for the same duration. Additionally, who knows what the consumption of chocolate was for the past 100 years.
Third, flavonoids are present in other foods like tea, wine and vegetables and fruits. Shouldn’t the intake of any of these effect the correlation?
Fourth, correlation does not imply causation, it just shows the degree of relationship between the two parameters or factors and no more, no less.
In conclusion, it is tempting to advocate the consumption of chocolate on a national level, but one has to be cautious to consider over-interpretation of such correlations.
Messerli FH. “Chocolate consumption, cognitive function, and Nobel Laureates”. New Engl. J Med 2012; 367: 1652-1564.
Linthwaite S and Fuller GN. “Milk, chocolate and Nobel Prizes” Pract. Neurol. 2013; 13: 63-67.
Maurage P et-al. “Does Chocolate Consumption really boost Nobel award chances?”. J Nutr. 2013; 143: 931-933.
Gambale R. “Statistics and Medicine; the indispensable know-how of the researcher”. Translational Med 2013; 5; 28-31.