by Ari Magill, MD
The positive effects are largely attributable to its flavonoids.2 These bioactive chemicals, ubiquitously found in vegetables and fruits, are part of a larger class of compounds known as polyphenols, which have powerful antioxidant properties.3 They constitute 12% to 18% of cocoa’s total dry weight!2
Subjects who received the dark chocolate performed significantly better on measures of verbal episodic memory compared to those who received the white chocolate.
Mood was measured using two different questionnaires and was not significantly affected by chocolate consumption.
A major source of the bitter flavor in chocolate is flavonols. But this is often masked through extensive processing and other flavorings.6
Gratton et al investigated how cocoa flavanols (CFs) might enhance short-term cognitive function in young disease-free adults and protect against later cognitive deterioration.7 Their research demonstrated that CFs increased the speed and magnitude of oxygenation in the cortex, the outer surface of the brain, following a breathing challenge that induced high levels of carbon dioxide (rapid, shallow breathing will do this).
Many studies have been conducted to assess the potential of CFs for enhancing cognitive function in the elderly. A study by Brickman et al focused on a part of the brain correlated with age-related cognitive decline, the dentate gyrus (DG) of the hippocampus, the memory center of the brain.8 Consumption of CFs raised DG activity compared to controls.
Mastroiacovo et al examined the effect of three different doses of CFs on cognitive performance over the course of eight weeks.9 Investigators enrolled 90 cognitively normal seniors between the ages of 61 and 85 who were randomly assigned to receive 993 mg [high flavanol (HF)], 520 mg [intermediate flavanol (IF)], or 48 mg [low flavanol (LF)] of CFs mixed into a drink. Cognitive testing took place at baseline and then at eight weeks.
MMSE scores did not differ significantly after intervention with CFs.
HF and IF consumption significantly reduced the amount of time needed to complete a trial-marking test, compared to participants imbibing the LF beverage. Verbal fluency increased in all flavanol groups, but HF boosted it the most.
A biomarker analysis showed that decreases in insulin resistance in the HF-consuming group most strongly correlated with improvements in test scores, suggesting that insulin sensitivity might play a critical role in cognitive performance.
Another key molecule that promotes cognitive function is brain-derived neurotrophic factor (BDNF). One of a family of protein-signaling molecules known as neurotrophic factors, it plays a vital role in the growth, maintenance, and proliferation of neurons (the defining cells of the nervous system). Neshatdoust et al investigated how BDNF levels and mental acuity were influenced by a CF beverage with HF vs LF content.10 The HF or LF drink was given to 40 healthy elderly volunteers for 12 weeks. HF consumption was associated with significantly greater BDNF and composite global cognition levels compared to LF consumption.
Desideri et al assessed the cognitive benefit of a cocoa flavanol beverage in subjects with mild cognitive impairment, a prodromal stage that often but not always progresses to Alzheimer’s disease.11 Investigators enrolled 90 senior participants who were randomly given drinks containing either around 990 mg (HF), 520 mg (IF), or 45 mg (LF) of CFs daily for eight weeks. Trail-marking test speed significantly increased in the HF and IF groups compared to the LF one. Verbal fluency performance was significantly better in the HF group compared to the LF group. Notably, the correlation between insulin sensitivity and cognitive function was even more pronounced in this cognitively impaired population.
Overall, a growing body of literature is suggesting that cocoa flavonoids might help to preserve cognitive function as we age. Further studies are needed to confirm and better define that role.
As a popular food item, cocoa is generally considered to be very safe. It can trigger migraine headaches12 and skin and other allergies, which may occur as a reaction to trace metals, including nickel, that can be present in cocoa.13 Cocoa also contains low levels of stimulants, such as caffeine and theobromine, that in excess might promote symptoms such as anxiety, insomnia, or tachycardia.14
If you want to take your cocoa flavanol intake to the next level, the chocolate manufacturer, Mars, has created a supplement product, called CocoaVia.TM Online, a 60-capsule bottle, containing 450 mg cocoa flavanols in every two capsules, can be purchased for about $45.
b White chocolate contains no cocoa solids, where flavonoids are found, only cocoa butter, which consists of a mixture of monounsaturated and saturated fats.6
- Sokolov AN, et al. Chocolate and the brain: neurobiological impact of cocoa flavanols on cognition and behavior. Neurosci Biobehav Rev. 2013;37(10):2445-2453. doi: 10.1016/j.neubiorev.2013.06.013.
- Lamuela-Raventós RM, et al. Health effects of cocoa flavonoids. Food Sci Technol Int. 2005;11(3):159-176. doi.org/10.1177/1082013205054498.
- Manach C, et al. Polyphenols: food sources and bioavailability. Am J Clin Nutr. 2004;79(5):727-747. doi: 10.1093/ajcn/79.5.727.
- Bisson J-F, et al. Effects of long-term administration of a cocoa polyphenolic extract (Acticoa powder) on cognitive performances in aged rats. Br J Nutr. 2008;100(1):94-101. doi: 10.1017/S0007114507886375.
- Lamport DJ, et al. Beneficial effects of dark chocolate for episodic memory in healthy young adults: a parallel-groups acute intervention with a white chocolate control. Nutrients. 2020;12(2):483. doi: 10.3390/nu12020483.
- Katz DL, et al. Cocoa and chocolate in human health and disease. Antiox Redox Signal. 2011;15(10):2779-2811. doi: 1089/ars.2010.3697.
- Gratton G, et al. Dietary flavanols improve cerebral cortical oxygenation and cognition in healthy adults. Sci Rep. 2020;10(1):19409. doi: 10.1038/s41598-020-76160-9.
- Brickman AM, et al. Enhancing dentate gyrus function with dietary flavanols improves cognition in older adults. Nat Neurosci. 2014;17(12):1798-1803. doi: 10.1038/nn.3850.
- Mastroiacovo D, et al. 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;101(3):538-548. doi: 10.3945/ajcn.114.092189.
- Neshatdoust S, et al. High-flavonoid intake induces cognitive improvements linked to changes in serum brain-derived neurotrophic factor: two randomised, controlled trials. Nutr Healthy Aging. 2016;4(1):81-93. doi: 10.3233/NHA-1615.
- 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):794-801. doi:10.1161/HYPERTENSIONAHA.112.193060.
- Finocchi C, Sivori G. Food as trigger and aggravating factor of migraine. Neurol Sci. 2012;33(suppl 1):S77-80. doi: 10.1007/s10072-012-1046-5.
- Krecisz B, et al. Systemic contact dermatitis to nickel present in cocoa in 14‐year‐old boy. Pediatr Dermatol. 2011;28(3):335-336. doi: 10.1111/j.1525-1470.2011.01235.x.
- Socci V, et al. Enhancing human cognition with cocoa flavonoids. Front Nutr. 2017;4:19. doi: 10.3389/fnut.2017.00019.