Effect of cocoa extract supplementation on cognitive function: results from the clinic subcohort of the COSMOS trial

• Published in: The American journal of clinical nutrition Vol. 119; no. 1; pp. 39 - 48
• Main Authors: Vyas, Chirag M., Manson, JoAnn E., Sesso, Howard D., Rist, Pamela M., Weinberg, Alison, Kim, Eunjung, Moorthy, M Vinayaga, Cook, Nancy R., Okereke, Olivia I.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.01.2024; American Society for Clinical Nutrition, Inc; American Society for Nutrition
• Subjects: Adults; Aged; Assessments; Cacao; Cardiovascular diseases; Clinical trials; Cocoa; cocoa extract; Cognition; Cognition & reasoning; Cognitive ability; Diet; Dietary Supplements; Double-Blind Method; Epicatechin; Executive Function; Female; Flavanols; geriatric; Humans; Male; Memory; Neuropsychology; Older people; Original; Placebos; randomized clinical trial; Standard deviation; Subgroups; Supplements; Vitamins; CE; RCT; SU; CERAD; cognition; EBMT; MVM; CI; flavanols; randomized clinical trial; cocoa extract; ADRD; CN; CVD; HHIE-S; IRB; 3MS; TMT; geriatric; COSMOS; aMCI
• ISSN: 0002-9165; 1938-3207; 1938-3207
• DOI: 10.1016/j.ajcnut.2023.10.031

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. To test whether daily supplementation with CE, compared with placebo, produces better cognitive change over 2 y. 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. 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 [95% confidence interval (CI)]: −0.01 (−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. 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. This trial was registered at clinicaltrials.gov with identifier – NCT02422745.