Recently Messerli1 and Linthwaite and Fuller2 reported notably significant correlations between nations’ success rates in winning Nobel prizes and their per capita consumption of chocolate and milk. According to the authors, the mechanism might be that cognitive function is improved by consumption of flavonoids in chocolate and vitamin D in milk. Accordingly, I raise two questions with respect to the reported correlations:

• Dietary habit and availability are highly variable all over the world.3 Flavonoids and vitamins are also present in some other food items and beverages such as tea.4 Cumulative evidence suggests that tea has beneficial effects on cognitive function.5 Is the correlation between tea consumption and Nobel prizes comparable to the ones reported in the cases of chocolate and milk consumption?

• While food and nutrients represent very vague indicators of potential determinants of a population's level of cognitive performance, one may add a more comprehensive and meaningful component to this inquiry: the socioeconomic stratification of societies. There is abundant evidence of a causal link between social inequalities and poor population health across continents and countries.⁶ Is there a correlation between socioeconomic inequalities among nations and …