Impact of multivitamin-mineral and cocoa extract on incidence of mild cognitive impairment and dementia: Results from the COcoa Supplement and Multivitamin Outcomes Study for the Mind (COSMOS-Mind).

Abstract

We assessed the effects of multivitamin-mineral and cocoa extract supplementation on incident mild cognitive impairment (MCI) and all-cause probable dementia. COSMOS-Mind (N=2262), a 2×2 factorial, randomized-controlled clinical trial administered a telephone-based cognitive battery at baseline and annually for 3 years. Incidence rates of MCI, and separately dementia, were compared among treatment arms with proportional hazards regression. Over 3 years, 110 incident MCI and 14 incident dementia cases were adjudicated. Incidence rates did not vary by assignment to multivitamin-mineral or cocoa extract (all p's≥0.05); however, statistical power was low. When participants assigned to multivitamin-mineral versus placebo converted to MCI, their scores for global cognition (p=0.03) and executive function (p<0.001) were higher and had declined less relative to the previous year (p=0.03 for global cognition; p=0.004 for executive function). Multivitamin-mineral therapy may provide cognitive resilience, countering conversion to MCI, but not significantly reduce its incidence over 3 years. Multivitamin-mineral supplementation did not reduce risks for cognitive impairment. Cocoa extract supplementation did not reduce risks for cognitive impairment. Multivitamin-mineral supplementation slowed cognitive declines for incident mild cognitive impairment.