COSMOS-Mind: Daily Multivitamin Improves Cognition in Older Adults
No cognitive gains were seen from three years of administering cocoa extract
Three years of a daily multivitamin-mineral supplement improved memory, and cognitive and executive function in older adults, according to data from the COSMOS-Mind study.
Three years of administering cocoa extract every day had no effect on cognitive function, however.
“This is the first positive, large-scale, long-term study to show that multivitamin-mineral supplementation for older adults may slow cognitive aging,” Maria Carrillo, PhD, Alzheimer’s Association‘s chief science officer, said in a press release.
Additional studies are needed to confirm these findings in people with cognitive decline associated with conditions such as Alzheimer’s disease, the researchers noted. Carrillo said the association wasn’t ready to recommend a supplement to reduce cognitive decline risk in older adults.
“For now, and until there is more data, people should talk with their health care providers about the benefits and risks of all dietary supplements, including multivitamins,” Carrillo said.
COSMOS-Mind data were published in Alzheimer’s & Dementia, in the study “Effects of cocoa extract and a multivitamin on cognitive function: A randomized clinical trial.”
Alzheimer’s is a progressive disorder marked by memory loss, confusion, and a decline in reasoning skills. Effective interventions are needed to preserve cognitive function in those with the condition, especially if they are inexpensive and readily available.
Two such potential interventions — a daily multivitamin-mineral (MVM) and cocoa extract supplements — were evaluated for their impact on cognitive function in older adults in the COSMOS-Mind (COcoa Supplement and Multivitamin Outcomes Study of the Mind) study (NCT03035201).
The study was conducted by researchers at Wake Forest University School of Medicine, North Carolina, and Harvard Medical School’s Brigham and Women’s Hospital, Massachusetts.
Cocoa, in its unprocessed form, contains high levels of antioxidant flavonoids. Some studies suggest high doses of cocoa flavanols provide cognition-enhancing benefits. Although marketed to support cognition, MVM supplements have been tested in one large, appropriately controlled clinical trial that only included men.
COSMOS-Mind was part of the larger placebo-controlled clinical trial COSMOS (NCT02422745). It tested the effects of daily cocoa extract and/or an MVM on cardiovascular and cancer outcomes in more than 21,000 adults, ages 60 or older.
Overall, 2,262 COSMOS participants, 65 years or older (mean age 73; 1,348 women and 914 men) were enrolled in COSMOS-Mind.
Effects of multivitamin, cocoa extract on cognition
They were randomly assigned to receive either both MVM (Centrum Silver) and cocoa extract (Mars Edge) supplements (571 people), MVM supplements plus a cocoa placebo (551 people), cocoa extract supplements and an MVM placebo (553 people), or both placebos (587 people).
A standardized battery of cognitive tests was conducted by telephone at the study’s start (baseline) and once a year for three years.
Its primary goal was to assess cocoa extract-related changes in a global cognition outcome reported as a z-score — the difference between mean baseline and subsequent scores — with higher z-scores reflecting better performance.
Mean global cognitive scores of those who received cocoa extract and those given a cocoa placebo increased over the first two years and then stabilized, showing no significant difference between the two groups, results showed.
The two-year increase in scores across both groups was likely due to retest practice effects, the researchers noted. Further analyses suggested the global cognitive response to cocoa extract supplements may vary with a person’s body-mass index (BMI), a measure of body fat content.
Cocoa extract also showed no effect on episodic memory (everyday events) or executive function (planning, attention, and multitasking).
MVM supplement use was associated with a significant improvement in global cognitive function after three years over an MVM placebo, with a mean z-score difference of 0.7. The treatment response did not relate to MVM use at baseline.
Cardiovascular disease and performance
In the MVM group, z-scores were higher in those with a history of cardiovascular disease (CVD) compared with those without (0.14 vs. 0.6). Specifically, participants without CVD history showed greater cognitive performance than those with such history at baseline and subsequent assessments, regardless of treatment.
However, among those with a history of CVD, those given an MVM placebo had cognitive declines after a year, while those given MVM supplements saw improvement and were protected against cognitive decline.
Participants with a CVD history were more likely to be men, older, have a higher BMI or blood pressure, used more CVD medications, had more depression, and engaged in less physical activity. When participants with CVD history were excluded from the overall analysis, MVM’s effects on global cognitive function remained unchanged.
“Even though the pattern of results differed for subgroups with and without CVD at baseline, [three] years of MVM treatment improved global cognition for all participants, not just those with CVD history,” the researchers wrote.
Memory, executive function gains
MVM supplementation also led to significant improvements in episodic memory and executive function. Also, there was no interaction between cocoa extract and MVM supplements, indicating that “adding [cocoa extract] did not alter the benefit of MVM on cognition,” the research team wrote.
Although only 1,732 participants (77%) completed all three annual assessments, there was no evidence that differences in dropout rates across study groups affected the results. Lastly, the team reported no safety concerns from supplement use during the study.
“COSMOS-Mind provides the first evidence from a large-scale, long-term, pragmatic [appropriately controlled trial] to suggest that daily use of a safe, readily accessible, and relatively low-cost MVM supplement has the potential to improve or protect cognitive function for older women and men,” the researchers wrote.
These findings “could have important public health implications for brain health and resilience against future cognitive decline,” and “set the stage for new avenues of research to identify mechanisms and alternate approaches involving combination therapy,” they added.
Carillo said it was “critical that future treatments and preventions are effective in all populations” and called for “independent confirmatory studies” among “larger, more diverse study populations.”
“We envision a future where there are multiple treatments and risk reduction strategies available that address cognitive aging and dementia in multiple ways — like heart disease and cancer — and that can be combined into powerful combination therapies … in conjunction with brain-healthy guidelines for lifestyle factors like diet and physical activity,” Carrillo said.