Mild cognitive impairment is a clinical diagnosis where mild memory deficits exist but afflicted individuals are otherwise highly functioning without evidence of dementia. Individuals with mild cognitive impairment are at increased risk of developing the more debilitating memory deficits of dementia. The treatment of mild cognitive impairment is an area of active research because intervention at this stage of disease could potentially delay or even avert the progression to dementia. Several dietary constituents have shown some memory benefit for individuals with mild cognitive and these include omega-3 fatty acids, vitamin B, vitamin D, and vitamin E. In addition, consumption of flavanoid containing plant based products such as tea, grape juice, red wine, apples, and hot cocoa drinks has show to be associated with decreased incidence of mild cognitive impairment and progression to dementia.
Researchers, lead by Dr. Giovambattista Desideri from University L’Aquila in Italy, have found that consumption of cocoa containing high levels of flavanols resulted in improved cognitive function, blood pressure, and insulin resistance in an elderly group with mild cognitive impairment. The results of their study were published online in the journal Hypertension. The investigators conducted a double blind, parallel arm study in 90 elderly individuals with mild cognitive impairment who were randomized to consume ounce daily for 8 weeks a drink containing high flavanol content, intermediate flavanol content, or low flavanol content. The cognitive function of the study participants was tested by Mini Mental State Examination (MMSE), Trail Making Test A and B, and verbal fluency test. Although MMSE was similar in all three groups, the groups with high and intermediate flavanols performed significantly better at the end of the study when assessed with trail making tests and verbal fluency testing. Insulin resistance, blood pressure, and lipid peroxidation showed marked improvements in the high and intermediate flavonol group compared to the low flavanol group.
The authors wrote, “…the results of the current study provide encouraging evidence that the regular inclusion of flavonol containing foods may be an effective dietary approach for improving some aspects of cognitive dysfunction in adults with [mild cognitive impairment]. Other than the possible direct effects of flavanols on cognitive function, general improvements in cardiovascular function and specific metabolic parameters could have, alone or in combination, played a role in improving cognitive performance in this study population”. In addition the authors wrote, “Although additional confirmatory studies are warranted, the findings reported herein suggest that the regular dietary inclusion of flavanols could be one element of a dietary approach to the maintaining and improving not only cardiovascular health but also specifically brain health”.
This is the first study to show that consumption of cocoa flavanols may be beneficial for improving memory in individuals with mild cognitive impairment. Although the investigators could not provide an exact mechanism for the observed memory benefit, improved insulin resistance, improved blood pressure, increased brain perfusion, and the antioxidative effects from flavanols may have contributed. Future studies will need to be performed to validate these results on a larger scale, as well as determine the amount of dietary cocoa flavanol needed to obtain optimal effects.
Giovambattista Desideri 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 Published online before print August 14, 2012, doi: 10.1161/HYPERTENSIONAHA.112.193060