• Cognition

In a recent paper Dr Messerli1 reported a strong correlation between a nation's chocolate consumption with the country's prowess in winning Nobel prizes per capita (see Carphology, in this issue). Messerli speculated that flavonoids within chocolate may contribute to this link by improving cognitive function—while recognising a correlation does not establish causation. However, chocolate is not usually consumed on its own, often being combined with milk either as a drink or as milk chocolate. Could the per capita milk consumption correlate with Nobel achievements?

We used data from Food and Agriculture Organization of the United Nations Statistics (http://www.fao.org/AG/AGAInfo/themes/en/dairy/home.html) and Messerli's data1 (see figure 1) and found a significant exponential correlation (r²=0.573; p<0.0001) between milk consumption per capita (in 2007) and Nobel prizes per capita.

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Figure 1

Correlation between countries' annual per capita milk consumption and the number of Nobel laureates per 10 million population.

This suggests an association, but with a ceiling effect. The strength of the association is of the same order as Messerli (chocolate vs Nobel prizes: r²=0.625). Much of the same caveats apply as to the correlation with chocolate consumption1; is this epiphenomenon, with milk consumption reflecting a strong educational system; do Nobel prize winners celebrate by drinking milk?

However, there's a plausible biological mechanism as milk is rich in vitamin D which may be linked with improved cognitive function.2 Another attraction is that the correlation with milk does not find Sweden an outlier, absolving the Nobel Committee from Messerli's suggestion of patriotic bias.1

So to improve your chances of winning Nobel prizes you should not only eat more chocolate but perhaps drink milk too: or strive for synergy with hot chocolate?