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

Background: Recent evidence has indicated that flavanol consumption may have many health benefits in humans, including improved cognitive activities. Objective: The aim was to evaluate the effect of flavanol consumption on cognitive performance in cognitively intact elderly subjects. Design: 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). Results: 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 after consumption of 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 VET score was significantly (P < 0.0001) greater in the HF group (7.7 +/- 1.1 words/60 s) than in 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 similar to 17% of changes in composite z score (partial r(2) = 0.1703, P < 0.0001). Conclusions: 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.