Overview
- Presented July 27 at NUTRITION 2026, a secondary analysis of the COcoa Supplement and Multivitamin Outcomes Study (COSMOS) reported that three years of daily multivitamin use produced small but statistically significant improvements in symptom burden and the combined clinical summary score on the Kansas City Cardiomyopathy Questionnaire.
- The analysis used data from 16,027 older COSMOS participants drawn from the larger 21,442-person randomized, double-blind, placebo-controlled trial and measured physical function and symptom burden using the validated KCCQ patient-reported tool.
- Benefits were concentrated in reduced symptom burden rather than large gains in physical ability, and the largest, clinically meaningful effects appeared in a subgroup of participants with carotid stenosis.
- Cocoa extract did not improve functional-health scores in the overall cohort, though a subgroup analysis suggested a possible benefit for participants with congestive heart failure.
- Investigators and organizers cautioned that these findings come from a conference abstract and secondary analyses that are not yet peer reviewed, and they called for targeted, peer-reviewed trials before changing clinical practice or making broad supplement recommendations.