Multivitamins Could Slow Cognitive Decline, , Studies Suggest. According to a new study, taking multivitamins could slow cognitive decline associated with aging by as much as two years. 'USA Today' reports that the study, conducted by researchers at Mass General Brigham, was the third part of the COcoa Supplement and Multivitamin Outcomes Study (COSMOS). All three studies showed that people who took a daily multivitamin for up to three years had higher cognitive test scores compared to those who took a placebo. The results from this latest report confirm consistent and statistically significant benefits of a daily multivitamin versus placebo for both memory and global cognition, Mass Brigham press release, via 'USA Today'. The three studies included more than 5,000 volunteers. The previous two studies evaluated participants over the phone and through web interviews for up to three years. The third and most recent study involved in-person evaluations of almost 600 volunteers. According to the Alzheimer's Association, by the year 2060, an estimated 13.8 million people in the U.S. over the age of 65 will suffer from Alzheimer's-related dementia. This concerning statistic highlights the urgency for developing medical treatments to prevent, slow or even cure Alzheimer's disease. . Cognitive decline is among the top health concerns for most older adults, and a daily supplement of multivitamins has the potential as an appealing and accessible approach to slow cognitive aging, Chirag Vyas, MBBS, study first author and instructor in investigation at the Department of Psychiatry at Massachusetts General Hospital (MGH), via 'USA Today'. Cognitive decline is among the top health concerns for most older adults, and a daily supplement of multivitamins has the potential as an appealing and accessible approach to slow cognitive aging, Chirag Vyas, MBBS, study first author and instructor in investigation at the Department of Psychiatry at Massachusetts General Hospital (MGH), via 'USA Today'