Can the antioxidants in cocoa aid cognition?
A growing body of evidence suggests that these rare compounds really can.
And the results of a new clinical trial in older people adds more support for the idea.
It’s common for brain functions to deteriorate with age, with the speed and extent of that decline depending on genetics, diet, and activity levels.
Delaying the onset of mental decline is a personal and societal concern, as life expectancy gets longer and populations age worldwide.
As we age, memory capacity begins to worsen, along with thinking speed, "executive” brain functions, and the ability to form long-term memories.
We’ve reported some of the earlier studies on cocoa and cognition; see these and related articles in the Cocoa, Tea & Coffee
section of our news archive:
Now, another trial supports the potential value of antioxidant-rich cocoa for preserving mental powers as we age.
New trial finds brain and vascular benefits in healthy seniors
The new trial was conducted by researchers from Italy’s University of L’Aquila and candy maker Mars, Inc. (Mastroiacovo D et al. 2015)
This was the second installment in a two-part investigation by the same team.
The first study found that high-flavanol cocoa produced cognitive and cardio-metabolic benefits in older adults who’d been diagnosed with mild cognitive impairment or MCI ... see Cocoa Bolstered Seniors' Brains
But it remained uncertain whether the benefits of cocoa flavanols would apply to people without MCI … so this second study was designed to address that question.
The team enrolled 90 men and women aged 61-85 years with no evidence of cognitive dysfunction, for a controlled, randomized, double-blind study.
The volunteers were placed in one of three groups, with each group assigned to consume a drink containing a different amount of cocoa flavanols (antioxidants) every day for eight weeks:
- High-flavanol cocoa - 993 mg/serving
- Medium-flavanol cocoa - 520 mg/serving
- Low-flavanol cocoa - 48 mg/serving
After eight weeks, the people in high-flavanol cocoa group showed significantly improved cognitive function scores, as well as improved insulin-resistance and blood pressure scores.
The high- and intermediate-flavanol cocoa drinks were produced using Mars’ patented Cocoapro® process (which protects flavanols from destruction), while the low-flavanol drink was made with a normal, highly processed, alkalized ("Dutched") cocoa powder.
Other than downing their assigned cocoa drink daily, the participants maintained their normal diets and lifestyles throughout the study.
At the start of the study and again after eight weeks, their cognitive function was assessed using a battery of tests that examined memory, retention, recall, and executive function.
Encouragingly, those in the high- and medium-flavanol drinks showed significant improvements in overall cognitive function after eight weeks.
The results suggest that even cognitively healthy people can rapidly benefit from regular consumption of cocoa flavanols.
In addition to evaluating cognitive function, the researchers also monitored insulin resistance, blood pressure, and other markers of cardio-metabolic health.
As with cognitive functions, there was also evidence of improvements in these cardio-metabolic outcomes.
Both systolic and diastolic blood pressures were reduced and insulin resistance was significantly improved in the high- and medium-flavanol groups.
In contrast, only a modest improvement in diastolic blood pressure was observed in the low-flavanol group, with no significant improvements in either systolic blood pressure or insulin resistance.
Scientists haven’t yet determined how cocoa flavanols improve cognitive function, but the study’s authors suggest that the improvements in insulin resistance and blood pressure could be partially responsible.
As lead author Giovambattista Desideri, M.D., said, "Earlier studies suggest a central role for insulin resistance in brain aging. These results could therefore provide some insight into a possible mechanism of action for the cognitive improvements we have observed.”
There has been significant evidence over the past decade that cocoa flavanols also improve vascular function.
Co-author Dr. Catherine Kwik-Uribe of Mars, Inc. pointed out the obvious: "Since the brain is a heavily vascularized tissue, we might also be looking at vascular improvements as underlying the observed improvements in cognitive function.”
Dr. Desideri and his team are planning their next steps: "Now we’d like to know how they [cocoa flavanols] work and how long the effects last. If these further studies confirm the findings … it may have the potential to affect the daily lives of millions of people worldwide.”
Although the study was funded by a chocolate maker, the co-authors were academic scientists and its findings fit with those of many other studies, so it should be taken seriously.
- Baggott MJ, Childs E, Hart AB, de Bruin E, Palmer AA, Wilkinson JE, de Wit H. Psychopharmacology of theobromine in healthy volunteers. Psychopharmacology (Berl). 2013 Jul;228(1):109-18. doi: 10.1007/s00213-013-3021-0. Epub 2013 Feb 19.
- Barragán Mejía G, Calderón Guzmán D, Juárez Olguín H, Hernández Martínez N, García Cruz E, Morales Ramírez A, Labra Ruiz N, Esquivel Jiménez G, Osnaya Brizuela N, García Álvarez R, Ontiveros Mendoza E. The administration of food supplemented with cocoa powder during nutritional recovery reduces damage caused by oxidative stress in rat brain. Naunyn Schmiedebergs Arch Pharmacol. 2011 Dec;384(6):499-504. Epub 2011 Aug 9.
- Brickman AM, Khan UA, Provenzano FA, Yeung LK, Suzuki W, Schroeter H, Wall M, Sloan RP, Small SA. Enhancing dentate gyrus function with dietary flavanols improves cognition in older adults. Nat Neurosci. 2014 Oct 26. doi: 10.1038/nn.3850. [Epub ahead of print]
- 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.
- Columbia University Medical Center (CUMC). Dietary Flavanols Reverse Age-Related Memory Decline: Findings strengthen link between specific brain region and normal memory decline. October 26, 2014. Accessed at http://newsroom.cumc.columbia.edu/blog/2014/10/26/flavanols-memory-decline/
- Crews WD Jr, Harrison DW, Wright JW. A double-blind, placebo-controlled, randomized trial of the effects of dark chocolate and cocoa on variables associated with neuropsychological functioning and cardiovascular health: clinical findings from a sample of healthy, cognitively intact older adults. Am J Clin Nutr. 2008 Apr;87(4):872-80.
- Desideri G, Kwik-Uribe C, Grassi D, Necozione S, Ghiadoni L, Mastroiacovo D, Raffaele A, Ferri L, Bocale R, Lechiara MC, Marini C, Ferri C. 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 Sep;60(3):794-801. doi: 10.1161/HYPERTENSIONAHA.112.193060. Epub 2012 Aug 14.
- Erdman JW Jr, Carson L, Kwik-Uribe C, Evans EM, Allen RR. Effects of cocoa flavanols on risk factors for cardiovascular disease. Asia Pac J Clin Nutr. 2008;17 Suppl 1:284-7. Review.
- Fisher ND, Sorond FA, Hollenberg NK. Cocoa flavanols and brain perfusion. J Cardiovasc Pharmacol. 2006;47 Suppl 2:S210-4. Francis ST, Head K, Morris PG, Macdonald IA. The effect of flavanol-rich cocoa on the fMRI response to a cognitive task in healthy young people. J Cardiovasc Pharmacol. 2006;47 Suppl 2:S215-20.
- Heiss C, Schroeter H, Balzer J, Kleinbongard P, Matern S, Sies H, Kelm M. Endothelial function, nitric oxide, and cocoa flavanols. J Cardiovasc Pharmacol. 2006;47 Suppl 2:S128-35; discussion S172-6. Review.
- Hooper L, Kay C, Abdelhamid A, Kroon PA, Cohn JS, Rimm EB, Cassidy A. Effects of chocolate, cocoa, and flavan-3-ols on cardiovascular health: a systematic review and meta-analysis of randomized trials. Am J Clin Nutr. 2012 Mar;95(3):740-51. Epub 2012 Feb 1. Review.
- Judelson DA, Preston AG, Miller DL, Muñoz CX, Kellogg MD, Lieberman HR. Effects of Theobromine and Caffeine on Mood and Vigilance. J Clin Psychopharmacol. 2013 Jun 12. [Epub ahead of print]
- Mars, Inc. Mounting Evidence Demonstrates Improved Cognitive Function From Cocoa Flavanol Consumption. January 6, 2015. Accessed at http://www.marssymbioscience.com/media/
- Mastroiacovo D, Kwik-Uribe C, Grassi D, Necozione S, Raffaele A, Pistacchio L, Righetti R, Bocale R, Lechiara MC, Marini C, Ferri C, Desideri G. Cocoa flavanol consumption improves cognitive function, blood pressure control, and metabolic profile in elderly subjects: the Cocoa, Cognition, and Aging (CoCoA) Study--a randomized controlled trial. Am J Clin Nutr. 2015 Mar;101(3):538-48. doi: 10.3945/ajcn.114.092189. Epub 2014 Dec 17.
- Pase MP, Scholey AB, Pipingas A, Kras M, Nolidin K, Gibbs A, Wesnes K, Stough C. Cocoa polyphenols enhance positive mood states but not cognitive performance: a randomized, placebo-controlled trial. J Psychopharmacol. 2013 May;27(5):451-8. doi: 10.1177/0269881112473791. Epub 2013 Jan 29.
- 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.
- Scheid L, Reusch A, Stehle P, Ellinger S. Antioxidant effects of cocoa and cocoa products ex vivo and in vivo: is there evidence from controlled intervention studies? Curr Opin Clin Nutr Metab Care. 2010 Nov;13(6):737-42. Review.
- 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.
- Sies H, Hollman PC, Grune T, Stahl W, Biesalski HK, Williamson G. Protection by flavanol-rich foods against vascular dysfunction and oxidative damage: 27th Hohenheim Consensus Conference. Adv Nutr. 2012 Mar 1;3(2):217-21. doi: 10.3945/an.111.001578.
- Sokolov AN, Pavlova MA, Klosterhalfen S, Enck P. Chocolate and the brain: neurobiological impact of cocoa flavanols on cognition and behavior. Neurosci Biobehav Rev. 2013 Dec;37(10 Pt 2):2445-53. doi: 10.1016/j.neubiorev.2013.06.013. Epub 2013 Jun 26. Review.
- Swinburne University of Technology (STU). Dark chocolate improves calmness. May 3, 2013. Accessed at http://www.swinburne.edu.au/chancellery/mediacentre/media-centre/news/2013/05/dark-chocolate-improves-calmness
- Tokede OA, Gaziano JM, Djoussé L. Effects of cocoa products/dark chocolate on serum lipids: a meta-analysis. Eur J Clin Nutr. 2011 Aug;65(8):879-86. doi: 10.1038/ejcn.2011.64. Epub 2011 May 11. Review.