Chocolate and cocoa may be good for memory … if you choose extra-dark chocolate or “raw,” non-Dutched cocoa.
The clinical evidence on chocolate remains preliminary, but is supported by bountiful lab evidence showing artery-health, blood-flow, and cholesterol-lowering benefits (Shrime MG et al. 2011; Tokede OA et al. 2011; Hooper L et al. 2012).
In recent years, clinical and lab research extended the benefits of cocoa's polyphenol compounds to brain health (Francis ST et al. 2006; Fisher ND et al. 2006; Shah ZA et al. 2010; Barragán Mejía G et al. 2011).
However, that research remains limited … and although it is mostly positive, a short-term trial failed to detect any “neuro-psychological” benefits in healthy older adults given dark chocolate and cocoa for six weeks (Crews WD Jr et al. 2008).
By now, it's pretty clear that the apparent heart- and brain-health benefits of raw cocoa and dark chocolate stem from the relatively rare “antioxidant” polyphenols compounds in cocoa, called flavanols.
Food-borne “antioxidants” … a truly misleading misnomer
Whole plant foods abound in so-called “antioxidants” – primarily carotenes (carrots, squash, peppers, and wild salmon) and polyphenols, which occur in most plant foods … but most abundantly in berries, cocoa, tea, onions, beans, and whole grains.
Among other likely beneficial effects, these compounds' known “nutrigenomic” influences on gene switches and “cell-signaling” tend to reduce unhealthful levels of oxidation and inflammation.
The apparent health benefits of plant foods rich in carotenes and polyphenols almost certainly flow from these nutrigenomic effects, rather than from direct antioxidant effects in the body.
Along with ample evidence for the benefits of fiber and other “phyto-nutrients,” evidence linking diets rich in fruits and vegetables to beneficial nutrigenomic effects may well explain why such diets are associated with a lower risk of Alzheimer's and other degenerative diseases.
Antioxidants in name only
The so-called antioxidants found in berries, tea, cocoa, and most plant foods (as well as wild salmon) can neutralize pro-oxidant free radicals in the test tube … but they don't do that in the body, at least not directly.
That general rule applies to the polyphenols in cocoa, which exert unusually powerful antioxidant effects in test tube studies, but not in the body (Scheid L et al. 2010).
Instead, compounds such as polyphenols and carotenes appear to deliver indirect antioxidant, anti-inflammatory benefits (Selmi C et al. 2006; Persson IA et al. 2011).
The most abundant flavanol in cocoa by far is epicatechin (ep-ih-kat-eh-kin), which abounds only in “raw,” non-Dutched cocoa and in green and white tea.
Scientists now report clinical evidence that dark chocolate or raw cocoa powder rich in flavanols may enhance memory in healthy middle-aged people.
In short, the results of a small clinical study showed that people who consumed flavanol-rich cocoa or chocolate routinely remembered things with less effort.
This study comes from the Center for Human Psychopharmacology at Swinburne University in Australia, and was funded by chocolate maker Barry Callebaut.
This is the first clinically proven link between consumption of high flavanol cocoa and chocolate to improved brain performance.
Aussie study detects memory advantage
A team led by Professor Andrew Scholey recruited 63 volunteers between the ages of 40 and 65 for their randomized, controlled, double-blind trial (Camfield DA et al. 2012).
The participants were divided into three groups, each of which consumed a chocolate beverage daily for 30 days.
Critically, each group's beverage contained 10 grams (1/3 oz) of chocolate, but each beverage delivered a different dose of cocoa flavanols:
Group 1 – Dark, high-flavanol chocolate (500mg of cocoa flavanols)
Group 2 – Dark, medium-flavanol chocolate (250mg of cocoa flavanols)
Group 3 (control) – Dark, low-flavanol chocolate (almost no cocoa flavanols)
The amount of flavanols in the “high-flavanol” chocolate consumed daily by the people in Group 1 (500mg) was actually slightly lower than the amount found in 10 grams – less than 1/5 of a bar – of Vital Choice Organic 80% Extra Dark Chocolate (577mg).
The amount of flavanols in the beverage consumed by Group 2 approximated the amount in 10 grams (1/3 oz) of a chocolate bar containing 40 to 50 percent cocoa solids.
To minimize dietary influences on the results, the volunteers were not allowed to consume flavonoid-rich fruits, products containing caffeine, or an excess of alcohol.
On the first and on the 30th day computer-tomography (CT) brain scans of the test subjects were made while participants solved tasks requiring “spatial working memory” … the ability to remember where objects appeared.
The subjects' performance was measured using the Steady State Visually-Evoked Potential method (SSVEP) of brain activity.
The speed and accuracy of the responses to a spatial working memory task were about the same in all three groups.
However, compared with those in the control group, the CT scans showed less stress in the brains of the high- and medium-flavanol group.
This means that the high- and medium-flavanol chocolate beverage lowered stress levels in the brain and allowed the test subjects to achieve the same performance with fewer brain resources.
As the researchers put it, “Cocoa flavanol consumption may increase neural [brain] efficiency in spatial working memory function” (Camfield DA et al. 2012).
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Camfield DA, Scholey A, Pipingas A, Silberstein R, Kras M, Nolidin K, Wesnes K, Pase M, Stough C. Steady state visually evoked potential (SSVEP) topography changes associated with cocoa flavanol consumption. Physiol Behav. 2012 Feb 28;105(4):948-57. Epub 2011 Nov 19.
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Persson IA, Persson K, Hägg S, Andersson RG. Effects of cocoa extract and dark chocolate on angiotensin-converting enzyme and nitric oxide in human endothelial cells and healthy volunteers--a nutrigenomics perspective. J Cardiovasc Pharmacol. 2011 Jan;57(1):44-50.
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Selmi C, Mao TK, Keen CL, Schmitz HH, Eric Gershwin M. The anti-inflammatory properties of cocoa flavanols. J Cardiovasc Pharmacol. 2006;47 Suppl 2:S163-71; discussion S172-6. Review.
Shah ZA, Li RC, Ahmad AS, Kensler TW, Yamamoto M, Biswal S, Doré S. The flavanol (-)-epicatechin prevents stroke damage through the Nrf2/HO1 pathway. J Cereb Blood Flow Metab. 2010 Dec;30(12):1951-61. Epub 2010 May 5.
Shrime MG, Bauer SR, McDonald AC, Chowdhury NH, Coltart CE, Ding EL. Flavonoid-rich cocoa consumption affects multiple cardiovascular risk factors in a meta-analysis of short-term studies. J Nutr. 2011 Nov;141(11):1982-8. Epub 2011 Sep 28.
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