Flavanol-rich chocolate

Cocoa

  • Food & Drink
  • Updated March 10, 2015

The cocoa bean is naturally high in flavanols—plant chemicals thought to protect from oxidative stress and other types of damage. While the process of creating cocoa and chocolate can often reduce the flavanol content, flavanol-rich cocoa or chocolate may improve cognitive function for elderly people. The benefits, however, are very small and specific. Whether it can protect against dementia is even less clear. On the plus side, safety concerns are minor and are generally limited to the caffeine and theobromine content, as well as the number of calories.

Evidence

A few clinical trials have tested high-flavanol cocoa in elderly people, while two observational studies have reported mixed results on the potential link between chocolate intake (regardless of flavanol levels) and the rate of cognitive decline. Our search found:

• 1 systematic review of clinical trials on mood or cognition
• 3 small clinical trials in elderly people
• 2 observational studies on chocolate intake and cognitive decline
• At least 3 preclinical studies

Potential Benefit

A handful of small clinical trials have suggested that while cocoa and cocoa flavanols might slightly improve cognitive function, most aspects of cognition are unaffected [1][2][3][4]. Cocoa or its flavanols may increase blood flow to the brain [4], which often decreases with aging [5] and in neurodegenerative diseases such as Alzheimer's [6]. The flavanols in cocoa may not be required for this effect [7]. In observational research, people who ate chocolate or cocoa regularly were just as likely to experience cognitive decline over five years [8], although another study reported that they tended to have better cognitive abilities [9]. Small potential benefits of cocoa or cocoa flavanols have also been reported for cardiovascular diseases and diabetes [10-14], which may also affect the risk of cognitive decline and dementia [15][16].

For Dementia Patients

There is no rigorous human research on the possible benefits of cocoa or related flavanols for dementia patients. One eight-week clinical trial with 90 people with mild cognitive impairments reported that a flavanol-enriched cocoa drink improved scores on two cognitive tests, lowered insulin resistance, and reduced blood pressure [3]. While these results are promising, further study is needed to confirm whether the benefits will improve quality of life or slow disease progression.

Safety

Chocolate, cocoa, and flavanol-enriched cocoa extracts have few known safety issues. There are concerns, however, related to the methylxanthines (caffeine and theobromine), sugars, saturated fat, and additional calories found in most chocolate products. Moderation is essential since chocolate often has very high caloric content, which could contribute to weight gain. Some researchers are exploring whether dark chocolate and cocoa flavanols could protect against obesity [17], but that research is not conclusive. Flavanol-rich cocoa, chocolate, and supplements are relatively new to the human diet, so little is known about their long-term safety.

NOTE: This is not a comprehensive safety evaluation or complete list of potentially harmful drug interactions. It is important to discuss safety issues with your physician before taking any new supplement or medication.

How to Use

Clinical studies have used daily doses of flavanol ranging from 520 to 990 mg. Dietary intake of flavanols is much lower, particularly for cocoa-related flavanols. If flavanols are the critical ingredients for possible health benefits, then the chocolate or cocoa commonly found in the diet may not be a good source, depending on ingredients, sourcing, and processing method. Milk chocolate contains less cocoa powder by weight than dark chocolate and, therefore, has a lower flavanol content. "Dutch" processing or alkalization lowers the amount of flavanols by 60 to 90 percent [18].

Learn More

Cognitive Vitality blog post, "Cocoa and Chocolate May Treat Cognitive Impairment"

Scientific American article, "Is Cocoa the Brain Drug of the Future?"

References

  1. Brickman, A.M., et al., Enhancing dentate gyrus function with dietary flavanols improves cognition in older adults. Nat Neurosci, 2014.
  2. Crews, W.D., Jr., D.W. Harrison, and J.W. Wright, 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. 87(4): p. 872-80.
  3. Desideri, G., 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(3): p. 794-801.
  4. Scholey, A. and L. Owen, Effects of chocolate on cognitive function and mood: a systematic review. Nutr Rev, 2013. 71(10): p. 665-81.
  5. Chen, J.J., H.D. Rosas, and D.H. Salat, Age-associated reductions in cerebral blood flow are independent from regional atrophy. Neuroimage, 2011. 55(2): p. 468-78.
  6. Wierenga, C.E., C.C. Hays, and Z.Z. Zlatar, Cerebral blood flow measured by arterial spin labeling MRI as a preclinical marker of Alzheimer's disease. J Alzheimers Dis, 2014. 42(0): p. S411-9.
  7. Sorond, F.A., et al., Neurovascular coupling, cerebral white matter integrity, and response to cocoa in older people. Neurology, 2013. 81(10): p. 904-9.
  8. Vercambre, M.N., et al., Caffeine and cognitive decline in elderly women at high vascular risk. J Alzheimers Dis, 2013. 35(2): p. 413-21.
  9. Nurk, E., 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(1): p. 120-7.
  10. Hooper, L., et al., 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. 95(3): p. 740-51.
  11. Ried, K., et al., Effect of cocoa on blood pressure. Cochrane Database Syst Rev, 2012. 8: p. CD008893.
  12. Tokede, O.A., et al., Chocolate consumption and prevalence of metabolic syndrome in the NHLBI Family Heart Study. ESPEN J, 2012. 7(4): p. e139-e143.
  13. Tokede, O.A., J.M. Gaziano, and L. Djousse, Effects of cocoa products/dark chocolate on serum lipids: a meta-analysis. Eur J Clin Nutr, 2011. 65(8): p. 879-86.
  14. Buitrago-Lopez, A., et al., Chocolate consumption and cardiometabolic disorders: systematic review and meta-analysis. BMJ, 2011. 343: p. d4488.
  15. Barnes, D.E. and K. Yaffe, The projected effect of risk factor reduction on Alzheimer's disease prevalence. Lancet Neurol., 2011. 10(9): p. 819-828.
  16. Sadanand, S., R. Balachandar, and S. Bharath, Memory and executive functions in persons with type 2 diabetes: a meta-analysis. Diabetes Metab Res Rev, 2016. 32(2): p. 132-42.
  17. Farhat, G., et al., Dark chocolate: an obesity paradox or a culprit for weight gain? Phytother Res, 2014. 28(6): p. 791-7.
  18. 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.