According to ancillary study of data from the COSMOS (Cocoa Supplement and Multivitamin Outcomes) Study, called COSMOS-Mind, daily supplementation with a multivitamin/mineral supplement may lead to benefits in cognition in older adults. This study, conducted by Wake Forest University School of Medicine in collaboration with Brigham and Women’s Hospital, was published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.

COSMOS is a large-scale, longitudinal study involving 10,719 participants, which assessed primary outcomes related to cardiovascular disease and cardiovascular mortality in relation to the use of a multivitamin/mineral supplement, Centrum Silver, and a cocoa extract standardized to 500 mg/day of flavanols, similar to Mars’ branded supplement CocoaVia Cardio Health. Groups were randomized to receive either a placebo, a cocoa extract, a multivitamin/mineral supplement, or both a cocoa extract and multivitamin/mineral.

In the present study, which tracked data from 2,262 participants with a mean age of 73 years old, participants took part in standardized tests including the Telephone Interview of Cognitive Status, World List and Story Recall, Oral Trail-making, Verbal Fluency, Number Span, and Digit Ordering tests.

“Identifying a safe, affordable, and accessible intervention to protect cognitive function against decline in older adults is a pressing public health priority,” the authors wrote. A subclass of flavonoids called flavanols, which are found in cocoa, are thought to have the potential to slow cognitive decline through improved cerebral vasodilation, blood flow, perfusion, and angiogenesis. Recent research reviews suggest that memory and executive function tend to benefit the most from high daily doses of cocoa flavanols.

“Individual micronutrients and minerals target multiple biologic pathways that support normal body and brain function, and deficiencies in older adults may increase the risk for cognitive decline and dementia,” the authors continued. “Longer-term daily intake of a multivitamin-mineral alone or with other dietary supplements to enhance global cognitive function in older adults has been examined in just one large randomized controlled trial, which included only male physicians. Further study is needed given their widespread use in the general population.”

Daily multivitamin/mineral supplementation resulted in statistically significant benefits on global cognition, episodic memory, and executive function in older adults compared to placebo, but cocoa extract supplementation did not have any significant interaction with any of the cognitive domains tested.

Notably, multivitamin/minerals were linked to the greatest cognitive benefit in adults with cardiovascular disease. To estimate the clinical significance of the findings, the researchers modeled treatment-related protection against cognitive aging, and concluded that compared to placebo, 3 years of multivitamin/mineral supplementation slowed cognitive aging by 60%, or by 1.8 years, compared to baseline.

The only other long-term multivitamin/mineral randomized controlled trial conducted prior to COSMOS was the 12-year Physician’s Health Study II (PHS-II) of older U.S. male physicians that tested whether a daily multivitamin/mineral supplement prevented risk of major cardiovascular disease and cancer, the authors noted; in a cognitive substudy of PHS-II, there were no significant effects on global cognition composite.

“There are several differences between COSMOS-Mind and PHS-II worth highlighting,” the authors wrote, such as that the cohorts differed on key baseline characteristics. COSMOS was a much more ethnically diverse cohort, compared to PHS-II, which was predominantly white and non-Hispanic male physicians.

COSMOS-Mind also administered additional tests of executive function and more challenging episodic memory tests than PHS-II. Further, initial cognitive testing didn’t begin until 2.5 years into the intervention period, nearly at the final follow-up assessment time for COSMOS-Mind. “Our data suggest that MVM treatment effects increased from baseline in the first two years and then remained stable between years two and three,” they wrote. “As a result, any early cognitive benefits of MVM in PHS-II would likely have been missed because of their assessment schedule […]”

Components of the supplements used in each study also differed. COSMOS added lutein and lycopene, and the amounts of vitamins D and K were higher, with lower amounts of vitamin A, iron, magnesium, and copper.

Realizing the Full Potential of Multivitamins

This study holds a great deal of promise for a relatively under-examined health role of multivitamins, according to Andrea Wong, senior vice president of scientific and regulatory affairs at the Council for Responsible Nutrition (CRN), and the full potential of multivitamin supplementation has yet to be realized.

“Research has already established that multivitamins can help to fill nutrient gaps. Beyond this, the Physician’s Health Study II, a large-scale clinical trial, showed an 8% reduction in overall cancer risk in older male physicians who took a daily multivitamin as well as a significant decrease in cataract risk. The COSMOS-Mind study provides evidence that daily multivitamin consumption may benefit cognitive function in older men and women. With further research, the full potential for multivitamins in protecting and enhancing health could be realized.”

Duffy MacKay, senior vice president of dietary supplements at the Consumer Healthcare Products Association (CHPA) expressed similar enthusiasm about the findings.

“The promising results of this clinical trial, showing improved global cognition, episodic memory, and executive function in older adults after three years of daily multivitamin-mineral use, provides first-time evidence that dietary supplementation can be effective in helping older consumers protect and improve cognition.”

Mark Espeland, principal investigator on the COSMOS-Mind trial, is scheduled to speak at CHPA’s Regulatory, Scientific, and Quality Conference Sep. 20-21.

“While there is no proven prevention or treatment for cognitive decline, we know that science grows in increments,” said MacKay, “and this study is one step toward reinforcing the beneficial role of a safe, accessible, and affordable dietary supplement that can be used to optimize health through self-care.”

Still, studies with even greater diversity and scope are still needed to draw any conclusions, said Laura Baker, co-principal investigator of the trial. “It’s too early to recommend daily multivitamin supplementation to prevent cognitive decline,” Baker said. “While these preliminary findings are promising, additional research is needed in a larger and more diverse group of people. Also, we still have work to do to better understand why the multivitamin might benefit cognition in older adults.”