Effect of cocoa extract supplementation on cognitive function: results from the clinic subcohort of the COSMOS trial.
- 2024-01
- The American journal of clinical nutrition 119(1)
- Chirag M Vyas
- JoAnn E Manson
- Howard D Sesso
- Pamela M Rist
- Alison Weinberg
- Eunjung Kim
- M Vinayaga Moorthy
- Nancy R Cook
- Olivia I Okereke
- PubMed: 38070683
- DOI: 10.1016/j.ajcnut.2023.10.031
Study Design
- Type
- Clinical Trial
- Sample size
- n = 573
- Population
- 573 United States adults aged ≥60 y from the COSMOS-Clinic subcohort
- Methods
- Randomized, double-blind, placebo-controlled, 2 × 2 factorial trial, daily supplementation with cocoa extract (500 mg flavanols/d including 80 mg (-)-epicatechin) or placebo for 2 years
- Duration
- 2 y
- Funding
- Unclear
- Large Human Trial
Background
Some prior randomized clinical trials (RCTs) that tested the effects of cocoa extract (CE), a source of flavanols, on late-life cognition have yielded promising findings. A long-term RCT using in-person neuropsychological tests covering multiple cognitive domains may clarify the cognitive effects of CE.Objectives
To test whether daily supplementation with CE, compared with placebo, produces better cognitive change over 2 y.Methods
The COcoa Supplement and Multivitamin Outcomes Study (COSMOS) is a 2 × 2 factorial RCT of 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 United States adults aged ≥60 y. There were 573 participants in the clinic subcohort of COSMOS (that is, COSMOS-Clinic) who completed all cognitive tests at baseline; of these, 492 completed 2-y follow-up assessments. The primary outcome was global cognition (averaging z-scores across 11 tests). Secondary outcomes were episodic memory and executive function/attention. Repeated measures models were used to compare randomized groups.Results
Participants' mean age (standard deviation) was 69.6 (5.3); 49.2% were females. Daily supplementation with CE, compared with placebo, had no significant effect on 2-y change in global cognition {mean difference (-0.08, 0.05) standard deviation units (SU)}. CE, compared with placebo, had no significant effects on 2-y change in episodic memory [mean difference (95% CI): -0.01 (-0.13, 0.10) SU] or executive function/attention [mean difference (95% CI): 0.003 (-0.07, 0.08) SU]. Subgroup analyses uncorrected for multiple-testing suggested cognitive benefits of CE supplementation, compared with placebo among those with poorer baseline diet quality.Conclusions
Among 573 older adults who underwent repeat in-person, detailed neuropsychological assessments over 2 y, daily CE supplementation, compared with placebo, showed no overall benefits for global or domain-specific cognitive function. Possible cognitive benefits of CE among those with poorer diet quality warrant further study.Trial registration
This trial was registered at clinicaltrials.gov with identifier - NCT02422745.Research Insights
CE, compared with placebo, had no significant effects on 2-y change in episodic memory [mean difference (95% CI): -0.01 (-0.13, 0.10) SU]
- Effect
- Neutral
- Effect size
- Small
- Dose
- 500 mg flavanols/d, including 80 mg (-)-epicatechin
CE, compared with placebo, had no significant effects on 2-y change in ... executive function/attention [mean difference (95% CI): 0.003 (-0.07, 0.08) SU]
- Effect
- Neutral
- Effect size
- Small
- Dose
- 500 mg flavanols/d, including 80 mg (-)-epicatechin
Daily supplementation with CE, compared with placebo, had no significant effect on 2-y change in global cognition {mean difference [95% confidence interval (CI)]: -0.01 (-0.08, 0.05) standard deviation units (SU)}.
- Effect
- Neutral
- Effect size
- Small
- Dose
- 500 mg flavanols/d, including 80 mg (-)-epicatechin