Cocoa extract fails to deliver cognitive benefits in adults

Taking cocoa extract (CE) supplements daily appears to be no better than placebo in improving the cognitive function of older adults who underwent repeat in-person, detailed neuropsychological assessments over 2 years, a study has shown.

A randomized controlled trial (COSMOS) was conducted on CE (500 mg flavanols/d, including 80 mg epicatechin) and/or a daily multivitamin-mineral supplement for cardiovascular disease and cancer prevention among 21,442 US adults aged ≥60 years. The authors compared randomized groups using repeated measures models.

A total of 573 participants (mean age 69.6 years, 49.2 percent females) in the clinic subcohort of COSMOS completed all cognitive tests at baseline, of whom 492 completed 2-year follow-up assessments. Global cognition (averaging z-scores across 11 tests) was the primary outcome, while episodic memory and executive function/attention were secondary.

Compared with placebo, daily supplementation with CE did not lead to a significant change in global cognition (mean difference [MD], ‒0.01, 95 percent confidence interval [CI], ‒0.08 to 0.05), episodic memory (MD, ‒0.01, 95 percent CI, ‒0.13 to 0.10), or executive function/attention (MD, 0.003, 95 percent CI, ‒0.07 to 0.08) at 2 years.

In subgroup analyses uncorrected for multiple testing, CE supplementation seemed to provide cognitive benefits among participants with poorer baseline diet quality compared with placebo.

“Possible cognitive benefits of CE among those with poorer diet quality warrant further study,” the authors said.