Research Paper Title
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.
Recent evidence has indicated that flavanol consumption may have many health benefits in humans, including improved cognitive activities. As such the aim was to evaluate the effect of flavanol consumption on cognitive performance in cognitively intact elderly subjects.
This was a double-blind, controlled, parallel-arm study conducted in 90 elderly individuals without clinical evidence of cognitive dysfunction who were randomly assigned to consume daily for 8 wk a drink containing 993 mg [high flavanol (HF)], 520 mg [intermediate flavanol (IF)], or 48 mg [low flavanol (LF)] cocoa flavanols (CFs). Cognitive function was assessed at baseline and after 8 wk by using the Mini-Mental State Examination (MMSE), the Trail Making Test (TMT) A and B, and the Verbal Fluency Test (VFT).
The changes in MMSE score in response to the 3 different treatments were not different. In contrast, there was a positive impact of the intervention on specific aspects of cognitive function. Mean changes (±SEs) in the time required to complete the TMT A and B after consumption of the HF (−8.6 ± 0.4 and −16.5 ± 0.8 s, respectively) and IF (−6.7 ± 0.5 and −14.2 ± 0.5 s, respectively) drinks significantly (P < 0.0001) differed from that with the LF drinks (−0.8 ± 1.6 and −1.1 ± 0.7 s, respectively). Similarly, VFT scores significantly improved among all treatment groups, but the magnitude of improvement in the VFT score was significantly (P < 0.0001) greater in the HF group (7.7 ± 1.1 words/60 s) in comparison to the IF (3.6 ± 1.2 words/60 s) and LF (1.3 ± 0.5 words/60 s) groups. Significantly different improvements in insulin resistance (P < 0.0001), blood pressure (P < 0.0001), and lipid peroxidation (P = 0.001) were also observed for the HF and IF groups in comparison with the LF group. Changes in insulin resistance explained ∼17% of changes in composite z score (partial r2 = 0.1703, P< 0.0001).
This dietary intervention study provides evidence that regular CF consumption can reduce some measures of age-related cognitive dysfunction, possibly through an improvement in insulin sensitivity. These data suggest that the habitual intake of flavanols can support healthy cognitive function with age.
Those in the Cocoa group performed better on test of verbal fluency and trail making but not on the MMSE. They also showed improvement in physiological measures such as blood pressure and insulin sensitivity.
First published December 17, 2014, doi: 10.3945/ajcn.114.092189
American Journal of Clinical Nutrition. February 2015 ajcn.092189.