Research - Does Chocolate Make You Clever

8/10/2019 Research - Does Chocolate Make You Clever

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Research

Chocolate vs cognitive

Desideri G, Kwik-Uribe C, Grossi D et al. Benefits in cognitive function, blood pressure, and insulin

resistance through cocoa flavours consumption in elderly subjects with mild cognitive impairment:

the cocoa cognitive , and aging (Cocoa) study. Hypertension. 2012;60 (3): 794801

Consume a daily cocoa drink with differing flavanol content, tested on 90 individuals with mild

cognitive impairment8 weeks.

Tested using drinks with 990mg, 520mg and 45mg of flavonoids.

Cognitive function assessed by:

Mini mental state examinations

Trial making tests A and B

Verbal fluency tests

Key findings: after 8 weeks, participants consuming high and intermediate flavanol cocoa products

and significantly better in the tests.

Benefits significant at 500mg/day

Earlier studies have reported cognitive benefits from flavanol sourced from other foods. (Concord

grape juice, 2010)

May 2013similar study on chocolate flavanols effects on cognition and mood self-rated

calmness and contentedness, but cognition was unaffected by chocolate in this study.

Flavanols that occur naturally in cocoa beans are easily destroyed during chocolate manufacturing.

Dark chocolate contains more flavanols than milk or white chocolate. Among dark chocolate, there

was almost 7-fold variation in content.

Low flavanols experimental group consumed commercial chocolate drinks. High-falvoured content:

cocoa pro produced by Mars Inc.

Presentation: Cocoa Polyphenols. Pennington Biomedical Research Center Division of Education.

Heli Roy, Shanna Lundy, Phillip Brantley, PBRC 2005

Cocoa and chocolate products have the highest concentration of flavonoids among commonly

consumed foods. Only 10% of cocoa powder is flavonoids

Switzerlandhighest chocolate consumptionestimated 9.9kg/yr/person

Flavanoids in cocoa/chocolate, catechin and epicatechin, exist in long polymers - up to 10

catechin/epicatechin units linked (other flavonoid rich foods contain 2/3 in each chain). Known to

have hydrogen-donating properties and metal-chelating antioxidant properties


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Roasting and alkali treatment to cocoa beans reduce flavanol content, alongside fermentation of the

beansAs much as 90% of the flavonoids can be lost during processing

7% to 35% cocoa in milk chocolate

30% to 80% cocoa in dark chocolate

0% cocoa in white chocolate

Factsheet: CVS Health Resouces. 8/1/2011, EBSCO CAM Review Board. Pg 2.

http://www.cvshealthresources.com/print.aspx?token=f75979d3-9c7c-4b16-af56-

3e122a3f19e3&chunkiid=144581

White chocolate contains little to no flavonoids.

Commercial dark chocolate can contain up to 500-2000mg of flavanols per 100g of chocolate

Pase MP, Scholey AB, Piping as A et al. 2013 May; 27(5): 451-8 J Psychopharmacol. Cocoa

polyphenols enhance positive mood states but not cognitive performance: a randomised placebo

controlled trial. Centre for Human Psychopharmacology, Swinburne University, Melbourne,

Australia.

Healthy middle aged participants

Drink chocolate drinks with 500mg, 250mg and 0mg of flavanolsdrink for 30 days

Cognition measured using the Cognitive Drug Research system.

72 participants

Cognition was unaffected by treatment at all time points immediately, several hours after, and 1

month later

His Test? Original data?

The New England Journal of Medicine, Franz H. Messerli, Chocolate Consumption, Cognitive

Function and Nobel Laureates. 2012 Massachusetts Medical Society, page 1-3

Testing for correlation between a countrys level of chocolate consumption and its populations

cognitive functionmeasured populations cognitive function through the number of Nobel

Laureates per capita.

No. of Nobel laureates for every 10 million persons in a given country.

Data from Chocosuisse, Theobroma-cacao and Caobisco.

Data available from 2011 for Switzerland, 2010 for 15 countries, 2004 for 5 countries and 2002 for

China

R= 0.791
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P < 0.0001

Implies a significant linear correlation

Excluded Sweden: r = 0.862

Slope: 0.4kg chocolate per capita per year to increase the number of Nobel laureates in a givencountry by 1.

Minimally effective chocolate dose: 2kg per year.

No apparent ceiling on the no. of Nobel laureates at the highest chocolate dose level of 11kg per

year.

Graph: Sweden = anomaly. Very high no. of Nobel laureates, not so much chocolate consumption.

23 countries tested

According to correlation, given 6.4kg/yr/capita, Sweden should have had 14 Nobel laureates but it

has 32.

Ruled Sweden as an anomaly because observed number > 2x expected number.

Present data based on country averages

Not known about the specific chocolate intake of the Nobel laureates

Dr Messerli reports regular daily chocolate consumption, mostly but not exclusively, in the form of

Lindts dark varieties

Malawi Med J. Sept 2012; 24(3): 69-71. A guide to appropriate use of correlation coefficient in

medical research MM Mukaka

2013 Lund Research Ltd. Laerd Statistics, Pearson Product-Moment Correlation

https://statistics.laerd.com/statistical-guides/pearson-correlation-coefficient-statistical-guide.php

The Pearson product-moment correlation does not take into consideration whether a variable has

been classified as a dependant or independent variable.

Assumptions:

Variables must be either interval or ratio measurements

Variables must be normally distributed Linear relationship
https://statistics.laerd.com/statistical-guides/pearson-correlation-coefficient-statistical-guide.phphttps://statistics.laerd.com/statistical-guides/pearson-correlation-coefficient-statistical-guide.phphttps://statistics.laerd.com/statistical-guides/pearson-correlation-coefficient-statistical-guide.php


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Outliers are removed

Homoscedasticity (variances along line of best fit remain similar as you move along the line)

At Work, Issue 40, Spring 2005: Institute for Work and Health, Toronto. What researchers mean

bystatistical significance.

P to describe the probability of observing such a large difference purely by chance in 2 groups of

exactly the same people.

So 0.0001 means 0.01% chance that not correlated

Below 0.005considered highly statistically significant

Pg 2: Topic #7: P-Value. Cornell edu.

https://lsc.cornell.edu/Sidebars/Stats%20Lab%20PDFs/Topic7.pdf

P-value is not the probability that the null hypothesis is true. Comparison of Bayesian and

classical approaches shows that a p-value can be very close to 0 while the posterior

probability of the null is very close to unity (Jeffreys-Lindley paradox)

Calculation of p-value is based on assumption that finding is the product of chance alone

Prosecutors fallacy: not the probability of falsely rejecting the null hypothesis

Significance level of the test is not determined by the p-value
https://lsc.cornell.edu/Sidebars/Stats%20Lab%20PDFs/Topic7.pdfhttps://lsc.cornell.edu/Sidebars/Stats%20Lab%20PDFs/Topic7.pdfhttps://lsc.cornell.edu/Sidebars/Stats%20Lab%20PDFs/Topic7.pdf

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Research - Does Chocolate Make You Clever