Chocolate may make the heart grow fonder, but does it make the brain grow larger? Coinciding with the recent announcement of this years Nobel Prize winners, this week a New England Journal of Medicine article investigated whether a correlation existed between a countries per capita chocolate consumption (mostly measured through Lindt® dark chocolate consumption) and their cumulative amount of Nobel Prize winners - a suggested surrogate measure for a countries overall intellect [1].
The author found a surprisingly almost perfect linear association between a county's chocolate consumption and its number of Nobel laureates. From this he calculated that to have any chance of a Nobel Laureate we all need to be each consuming 2kg of chocolate annually, and if we all increased our chocolate consumption by another 400g over the course of a year, we would produce one extra Nobel Laureate. And, can you have too much of a good thing? The answer it seems is an unequivocal no! The Swiss top the charts for the highest amount of Nobel Laureates and they munch their way through a whopping 11kg of the brown stuff annually.
Of course it is a light-hearted piece of research, and correlation never stretches to causation. But, what it does do is raise an interesting hypothesis to extend the rapidly advancing body of impressive evidence which support the notion of chocolate as a 'brain food'. It appears the benefits all come down to its content of a nifty group of phytochemicals called flavanols. Evidence exists for flavanols possessing a broad spectrum of health enhancing properties; acting as antioxidants, improving cardiovascular health, halting inflammation, inhibiting cancer and of course boosting the functioning of our gray matter. A high falvanol intake appears to slow down reductions in cognitive performance associated with aging. There is also evidence that they improve endothelial function and cause vasodilatation improving blood flow in the brain [1]. And, on a weight basis dark chocolate/cocoa is only exceeded by a few foods - such as buckwheat hulls, the cereal sorghum and cinnamon - for flavanol content [2]. Cocoa beverages have produced enhanced performance in terms of reaction times, response rates and accuracy in certain tests as well as reducing mental fatigue [3]. On top of this, eating chocolate is often followed by feelings of elevated mood, activation and joy, all of which help foster a more productive working attitude [4].
So, does your favourite chocolate bar a day really help you work, as well as rest and play? Not quite, because when it comes to flavanols and reaping their benefits, milk chocolate just doesn't cut it. Because of their acrid flavour - often requiring an acquired taste for enjoyment - the food industry is often not keen on keeping too many of them present. This especially applies to the milk chocolate confectionary choices which instead are laden with malefic sugar contents. Typically, the greater the cocoa percentage the higher the flavanol content, and usually it's the 50-90% cocoa content dark chocolate that has been shown in studies to confer benefit - such as in the case of our Nobel laureates. But as discussed in The Health Delusion, even still this can be a bit wishy washy, with cocoa bean genus selection and processing stages such as roasting, fermenting and dutching having a massive impact on the overall flavanol content.
Until chocolate comes with labels dictating its actual flavanol content, if you wish to join the coveted ranks of Nobel Prize winners, or merely aspire to the more modest goal of maintaining cognitive performance with advancing age, your best bet is regular consumption of dark chocolate of the highest cocoa content that still manages to appeal to your tastebuds.
1.Messerli, F.H., Chocolate Consumption, Cognitive Function, and Nobel Laureates. N Engl J Med, 2012.
2.Miller, K.B., et al., Impact of alkalization on the antioxidant and flavanol content of commercial cocoa powders. J Agric Food Chem, 2008. 56(18): p. 8527-33.
3.Scholey, A.B., et al., Consumption of cocoa flavanols results in acute improvements in mood and cognitive performance during sustained mental effort. J Psychopharmacol, 2010. 24(10): p. 1505-14.
4.Macht, M. and J. Mueller, Immediate effects of chocolate on experimentally induced mood states. Appetite, 2007. 49(3): p. 667-74.