Are there benefits to taking a multivitamin? Although the over-the-counter daily supplements are considered safe, many health institutions and experts consider them unnecessary unless a person has been diagnosed with a vitamin deficiency.
In spite of that, vitamins are quite popular — it’s estimated that about 1 in 3 Americans take supplements, and the classic once-a-day multivitamin accounts for about 40 percent of all vitamin sales, according to Penn Medicine.
For those devoted to their daily vitamins, good news: Taking a multivitamin was associated with maintaining cognitive health in older adults, according to findings published on September 14 in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.
Dementia is the loss of cognitive functioning, which includes things like the ability to think, remember and reason, to the point where it interferes with a person’s daily life, according to the National Institute on Aging.
Types of dementia include Alzheimer’s disease, Lewy body dementia, vascular dementia, and Parkinson’s disease, per the Centers for Disease Control and Prevention (CDC).
There’s an urgent need for safe and affordable interventions to protect cognition against decline in older adults, says co-lead author Laura D. Baker, PhD, professor of gerontology and geriatric medicine at Wake Forest University School of Medicine in Winston Salem, North Carolina.
Recent research suggests that the actual incidence of dementia cases around the globe will continue to climb as a result of people living longer, along with risk factors that include smoking, obesity and high blood sugar. A study published in January 2022 in The Lancet projected that the number of adults living with some form of dementia in the United States will double by 2050, rising from 5.2 million people to 10.5 million.
The trial was conducted in collaboration with Brigham and Women’s Hospital as part of the COSMOS trial (Cocoa Supplement and Multivitamin Outcomes Study), a study designed to examine the potential benefits in preventing heart disease, cancer, stroke, and other health outcomes.
Researchers randomized 21,442 men and women from across the United States. Those included in the trial were all over 65 years old (the average age was 73), 60 percent women, and 89 percent white.
Participants were placed into one of four groups in a “two-by-two” trial; in one study, people who took a daily cocoa extract (containing 500 milligrams per day flavanols) were compared with those who took a placebo tablet, and in the second trial, people who took an over-the-counter daily multivitamin-mineral supplement were compared with a group taking a placebo supplement.
A cognitive test was performed over the phone to establish a baseline, and then repeated annually over the three-year follow-up. The test included a word list and story recall, verbal fluency, digit ordering, and other tools to measure memory as well as the speed and accuracy of cognitive processing.
The researchers went into the trial expecting the group taking the cocoa extract to reap the most cognitive benefits. That’s because cocoa extract is rich in compounds called flavanols (dark chocolate contains flavonoids) and past research suggests that these compounds may positively impact cognition, according to Baker. “There’s also preliminary data that shows that cocoa flavanols were very beneficial for cardiovascular health,” she says.
It’s thought that flavonoids work by potentially improving blood flow to the brain and reducing inflammation. “Anytime you can improve cardiovascular health, you improve cognition — they are intimately tied,” says Baker.
However, at the end of the study, the findings showed that those who took the cocoa extract containing flavanols didn’t show any cognitive improvements compared with the placebo group.
“That was not what we were expecting — we were kind of shocked that there was no benefit,” says Baker.
Just as surprising, investigators found that taking a daily multivitamin-mineral supplement resulted in statistically significant cognitive improvement. They estimated that three years of taking a multivitamin roughly translated to a 60 percent slowing of cognitive decline — about 1.8 years.
This is the first evidence of cognitive benefit in a large longer-term study of multivitamin supplementation in older adults, a finding that was also somewhat unexpected, says Baker. Previous studies that looked at cognition and multivitamins have showed mixed results, she adds.
Several micronutrients and minerals are needed to support normal body and brain function, and deficiencies in older adults may increase the risk for cognitive decline and dementia, and that’s where the multivitamin may provide some level of protection, says Baker.
Is there a specific vitamin or mineral that is especially beneficial for the brain? That’s not known, says Baker. If further research confirms that vitamins do indeed help with cognition, it may be that it’s not one specific vitamin or mineral but rather a synergistic effect of two or more components of the multivitamin that are providing the benefits, she says. “We still have work to do to better understand why the multivitamin might benefit cognition in older adults.”
The cognitive benefits in the group taking a daily vitamin were relatively more pronounced in participants with significant cardiovascular disease, a factor that the authors considered notable because these individuals are already at increased risk for cognitive impairment and decline.
“It’s too early to recommend daily multivitamin supplementation to prevent cognitive decline. If we’re going to make a strong recommendation around vitamins and cognition, we have to make sure it’s going to be good for everybody, and we don’t know that yet,” says Baker. While these preliminary findings are promising, additional research is needed in a larger and more diverse group of people, she adds.
“That being said, people are free to do whatever they want to do — it’s generally safe to take a multivitamin,” says Baker. Most vitamin manufacturers keep up with the latest science on the recommended amounts of different vitamins and minerals and adjust their formulations accordingly, she says.
While there is still more to be learned about vitamin supplements and brain health, we do know that even slight declines in our vitamin and micronutrient deficiencies can have consequences for the brain, says Baker. “Unfortunately, in the U.S., we tend to eat foods that are rich in saturated fats and a lot of carbohydrates and we often don’t eat enough of foods that are high in nutrient value,” she says.
The Cleveland Clinic offers the following nutritional tips to maintain a healthy brain:
- Eat a Mediterranean-style diet, which uses olive oil as the primary oil and emphasizes the intake of fruits, vegetables, legumes, nuts and seeds, moderate amounts of fish and dairy products and limited amounts of red and processed meats and sugar.
- Limit red meat.
- Eat fish rich in omega-3s, such as salmon, cod, haddock, tuna, or halibut. Walnuts, flaxseeds, and soybeans are also good sources of healthy fats.
- Eat plenty of fruits and vegetables. Data from a CDC report (PDF) published in January 2022 found that only about 1 in 8 adults consume the recommended 1.5 to 2 cups of fruit each day, and only 1 in 10 eat the recommended 2 to 3 cups of vegetables each day, including legumes.