CHOCOLAT NOBEL PDF

Nom original: CHOCOLAT NOBEL.pdf

Titre: Chocolate Consumption, Cognitive Function, and Nobel Laureates

Auteur: Messerli Franz H.

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The

n e w e ng l a n d j o u r na l

of

m e dic i n e

o c c a siona l no t e s

Chocolate Consumption, Cognitive Function,
and Nobel Laureates
Franz H. Messerli, M.D.

Dietary flavonoids, abundant in plant-based foods,
have been shown to improve cognitive function.
Specifically, a reduction in the risk of dementia,
enhanced performance on some cognitive tests,
and improved cognitive function in elderly patients
with mild impairment have been associated with
a regular intake of flavonoids.1,2 A subclass of
flavonoids called flavanols, which are widely
present in cocoa, green tea, red wine, and some
fruits, seems to be effective in slowing down or
even reversing the reductions in cognitive performance that occur with aging. Dietary flavanols
have also been shown to improve endothelial
function and to lower blood pressure by causing
vasodilation in the peripheral vasculature and in
the brain.3,4 Improved cognitive performance
with the administration of a cocoa polyphenolic
extract has even been reported in aged Wistar–
Unilever rats.5
Since chocolate consumption could hypothetically improve cognitive function not only in individuals but also in whole populations, I wondered whether there would be a correlation
between a country’s level of chocolate consumption and its population’s cognitive function. To
my knowledge, no data on overall national cognitive function are publicly available. Conceivably, however, the total number of Nobel laureates per capita could 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.

Me thods
A list of countries ranked in terms of Nobel
laureates per capita was downloaded from
Wikipedia (http://en.wikipedia.org/wiki/List_of_
countries_by_Nobel_laureates_per_capita). Be1562

cause the population of a country is substantially
higher than its number of Nobel laureates, the
numbers had to be multiplied by 10 million.
Thus, the numbers must be read as the number
of Nobel laureates for every 10 million persons
in a given country.
All Nobel Prizes that were awarded through
October 10, 2011, were included. Data on per
capita yearly chocolate consumption in 22
countries was obtained from Chocosuisse
(www.chocosuisse.ch/web/chocosuisse/en/home),
Theobroma-cacao (www.theobroma-cacao.de/
wissen/wirtschaft/international/konsum), and
Caobisco (www.caobisco.com/page.asp?p=213).
Data were available from 2011 for 1 country
(Switzerland), from 2010 for 15 countries, from
2004 for 5 countries, and from 2002 for 1 country (China).

Re sult s
There was a close, significant linear correlation
(r = 0.791, P<0.0001) between chocolate consumption per capita and the number of Nobel
laureates per 10 million persons in a total of 23
countries (Fig. 1). When recalculated with the
exclusion of Sweden, the correlation coefficient
increased to 0.862. Switzerland was the top performer in terms of both the number of Nobel
laureates and chocolate consumption. The slope
of the regression line allows us to estimate that
it would take about 0.4 kg of chocolate per capita
per year to increase the number of Nobel laureates in a given country by 1. For the United States,
that would amount to 125 million kg per year.
The minimally effective chocolate dose seems to
hover around 2 kg per year, and the dose–response
curve reveals no apparent ceiling on the number
of Nobel laureates at the highest chocolate-dose
level of 11 kg per year.

n engl j med 367;16 nejm.org october 18, 2012

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Occasional Notes

35

Switzerland

Sweden
30

Nobel Laureates per 10 Million Population

r=0.791
P<0.0001

Denmark

25

Austria

Norway

20

United Kingdom

15

The Netherlands

United
States

Ireland
France

10

Belgium
Canada

Finland
Australia

Poland
Portugal Greece

5

Germany

Italy
Spain

Japan

0

China

Brazil

0

5

10

15

Chocolate Consumption (kg/yr/capita)
Figure 1. Correlation between Countries’ Annual Per Capita Chocolate Consumption and the Number of Nobel
Laureates per 10 Million Population.

Discussion
The principal finding of this study is a surprisingly powerful correlation between chocolate
intake per capita and the number of Nobel laureates in various countries. Of course, a correlation between X and Y does not prove causation
but indicates that either X influences Y, Y influences X, or X and Y are influenced by a common
underlying mechanism. However, since chocolate consumption has been documented to improve cognitive function, it seems most likely
that in a dose-dependent way, chocolate intake
provides the abundant fertile ground needed for
the sprouting of Nobel laureates. Obviously,
these findings are hypothesis-generating only
and will have to be tested in a prospective, randomized trial.
The only possible outlier in Figure 1 seems to
be Sweden. Given its per capita chocolate consumption of 6.4 kg per year, we would predict
that Sweden should have produced a total of
n engl j med 367;16

about 14 Nobel laureates, yet we observe 32.
Considering that in this instance the observed
number exceeds the expected number by a factor of more than 2, one cannot quite escape the
notion that either the Nobel Committee in
Stockholm has some inherent patriotic bias
when assessing the candidates for these awards
or, perhaps, that the Swedes are particularly
sensitive to chocolate, and even minuscule
amounts greatly enhance their cognition.
A second hypothesis, reverse causation —
that is, that enhanced cognitive performance
could stimulate countrywide chocolate consumption — must also be considered. It is conceivable that persons with superior cognitive
function (i.e., the cognoscenti) are more aware
of the health benefits of the flavanols in dark
chocolate and are therefore prone to increasing
their consumption. That receiving the Nobel
Prize would in itself increase chocolate intake
countrywide seems unlikely, although perhaps
celebratory events associated with this unique

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october 18, 2012

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1563

Occasional Notes

honor may trigger a widespread but most likely
transient increase.
Finally, as to a third hypothesis, it is difficult to identify a plausible common denominator that could possibly drive both chocolate consumption and the number of Nobel laureates
over many years. Differences in socioeconomic
status from country to country and geographic
and climatic factors may play some role, but
they fall short of fully explaining the close correlation observed.

S t udy Limitations

Nobel Prize, and it closely correlates with the
number of Nobel laureates in each country. It
remains to be determined whether the consumption of chocolate is the underlying mechanism
for the observed association with improved cognitive function.
Dr. Messerli reports regular daily chocolate consumption,
mostly but not exclusively in the form of Lindt’s dark varieties.
Disclosure forms provided by the author are available with the
full text of this article at NEJM.org.
From St. Luke’s–Roosevelt Hospital and Columbia University,
New York.
This article was published on October 10, 2012, at NEJM.org.

The present data are based on country averages,
and the specific chocolate intake of individual
Nobel laureates of the past and present remains
unknown. The cumulative dose of chocolate that
is needed to sufficiently increase the odds of being asked to travel to Stockholm is uncertain.
This research is evolving, since both the number
of Nobel laureates and chocolate consumption
are time-dependent variables and change from
year to year.

Conclusions
Chocolate consumption enhances cognitive function, which is a sine qua non for winning the

1. Nurk E, Refsum H, Drevon CA, et al. Intake of flavonoid-rich

wine, tea, and chocolate by elderly men and women is associated
with better cognitive test performance. J Nutr 2009;139:120-7.
2. Desideri G, Kwik-Uribe C, Grassi D, et al. Benefits in cognitive function, blood pressure, and insulin resistance through
cocoa flavanol consumption in elderly subjects with mild cognitive impairment: the Cocoa, Cognition, and Aging (CoCoA)
Study. Hypertension 2012;60:794-801.
3. Corti R, Flammer AJ, Hollenberg NK, Lüscher TF. Cocoa and
cardiovascular health. Circulation 2009;119:1433-41.
4. Sorond FA, Lipsitz LA, Hollenberg NK, Fisher ND. Cerebral
blood flow response to flavanol-rich cocoa in healthy elderly
humans. Neuropsychiatr Dis Treat 2008;4:433-40.
5. Bisson JF, Nejdi A, Rozan P, Hidalgo S, Lalonde R, Messaoudi M. Effects of long-term administration of a cocoa polyphenolic extract (Acticoa powder) on cognitive performances in
aged rats. Br J Nutr 2008;100:94-101.
DOI: 10.1056/NEJMon1211064
Copyright © 2012 Massachusetts Medical Society.

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The New England Journal of Medicine
Downloaded from nejm.org by NAPOLEON PEREZ-FARINOS on October 18, 2012. For personal use only. No other uses without permission.
Copyright © 2012 Massachusetts Medical Society. All rights reserved.