“Effects of Cocoa Extract and a Multivitamin on Cognitive Function: A Randomized Clinical Trial”, 2022-09-14 ():
COSMOS-Mind was a large simple pragmatic randomized clinical trial in older adults conducted by mail and telephone.
The trial used a 2×2 factorial design to assess treatment effects of two different interventions within a single large study.
We found no cognitive benefit of daily cocoa extract administration (containing 500 mg flavanols) for 3 years.
Daily multivitamin-mineral (MVM) supplementation for 3 years improved global cognition, episodic memory, and executive function in older adults.
The MVM benefit appeared to be greater for adults with cardiovascular disease.
Background: Dietary supplements are touted for cognitive protection, but supporting evidence is mixed. COSMOS-Mind tested whether daily administration of cocoa extract (containing 500 mg/day flavanols) versus placebo and a commercial multivitamin-mineral (MVM) versus placebo improved cognition in older women and men.
Method: COSMOS-Mind, a large randomized 3-year 2×2 factorial trial, assessed cognition by telephone at baseline and annually. The primary outcome was a global cognition composite formed from mean standardized z-scores (relative to baseline) from individual tests, including the Telephone Interview of Cognitive Status, Word List and Story Recall, Oral Trail-Making, Verbal Fluency, Number Span, and Digit Ordering. Using intention-to-treat, the primary endpoint was change in this composite with 3 years of cocoa extract use. The pre-specified secondary endpoint was change in the composite with 3 years of MVM supplementation. Treatment effects were also examined for executive function and memory composite scores, and in pre-specified subgroups at higher risk for cognitive decline.
Results: A total of 2,262 participants were enrolled (mean age = 73y; 60% women; 89% non-Hispanic White), and 92% completed the baseline and at least one annual assessment. Cocoa extract had no effect on global cognition (mean z-score = 0.03, 95% CI: −0.02 to 0.08; p = 0.28). Daily MVM supplementation, relative to placebo, resulted in a statistically-significant benefit on global cognition (mean z = 0.07, 95% CI 0.02 to 0.12; p = 0.007), and this effect was most pronounced in participants with a history of cardiovascular disease (no history: 0.06, 95% CI 0.01 to 0.11; history: 0.14, 95% CI −0.02 to 0.31; interaction, nominal p = 0.01). Multivitamin-mineral benefits were also observed for memory and executive function. The cocoa extract by MVM group interaction was not statistically-significant for any of the cognitive composites.
Discussion: Cocoa extract did not benefit cognition. However, COSMOS-Mind provides the first evidence from a large, long-term, pragmatic trial to support the potential efficacy of a MVM to improve cognition in older adults. Additional work is needed to confirm these findings in a more diverse cohort and to identify mechanisms to account for MVM effects.