As our nation’s population ages, the number of Americans enduring cognitive decline grows with it. The Alzheimer’s Association, for example, estimates that about 6.7 million seniors were living with Alzheimer’s in 2023.
So it’s particularly encouraging that for the third time now, the COcoa Supplement and Multivitamin Outcomes Study (COSMOS) shows “consistent and statistically significant benefits of a daily multivitamin versus placebo for both memory and global cognition.”
“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,” lead author Chirag Vyas, MBBS, MPH, explained in a press release. Vyas is an instructor in investigation at the Department of Psychiatry at Massachusetts General Hospital (MGH), a founding member of the Mass General Brigham healthcare system.
The American Journal of Clinical Nutrition published the research results.
Mining a National Dataset
COSMOS is a randomized trial evaluating the effects of cocoa extract and multivitamin supplements on a large-scale, national scale. Mass General Brigham researchers continue to run the study, which includes 21,442 participants –12,666 women 65 and older and 8,776 men 60 and older. The scientists followed the participants for an average of 3.6 years through the end of 2020.
The COSMOS collection of cognitive studies represents a board-based collaboration between MGH, BWH, Columbia University, and Wake Forest University, leveraging new and traditional approaches to studying multiple health outcomes.
The COSMOS researchers published two previous studies that tested multivitamin supplementation on cognition using telephone-based cognitive assessments and web-based cognitive evaluations.
In this in-clinic study, the researchers administered detailed, face-to-face cognitive assessments among 573 participants in the subset of COSMOS called COSMOS-Clinic.
Encouraging Findings
The team also conducted a meta-analysis based on each study, with non-overlapping COSMOS participants (ranging between two and three years). The data presented strong evidence of benefits for both global cognition and episodic memory. The authors estimate that the daily multivitamin slowed global cognitive aging by the equivalent of two years compared to placebo.
Specifically, this latest research revealed “a modest benefit for the multivitamin, compared to placebo, on global cognition over two years.” The researchers also identified a statistically significant benefit in episodic memory because of the multivitamins. However, the research produced no change in executive function and attention.
“The meta-analysis of three separate cognition studies provides strong and consistent evidence that taking a daily multivitamin, containing more than 20 essential micronutrients, helps prevent memory loss and slow down cognitive aging,” Vyas concluded.
The supplements industry, including the Consumer Health Products Association (CHPA), lauded the findings.
“Even individuals with the healthiest diets often fail to reach the recommended daily intake level for vitamins and nutrients, CHPA Senior Vice President of Dietary Supplements Duffy MacKay said. “As we age, achieving this goal becomes even more important to protect memory and brain function.”
Not Everyone Agrees
The findings also seem to counter a recent backlash against dietary supplements in general.
In June 2022, for example, the U.S. Prevention Services Task Force (USPSTF), a volunteer group of research-driven primary care clinicians, published a report that advised that “the current evidence is insufficient to determine the benefits and harms of taking most vitamin, mineral, and multivitamin supplements to prevent heart disease, stroke, and cancer.”
And an earlier study, published in 2017, found that “This review showed little to no benefit of OTC supplement use in preventing cognitive decline, MCI, or Alzheimer-type dementia. Evidence is insufficient for health care providers to recommend any of the wide variety of OTC dietary supplements to patients with normal cognition or MCI.”
