No ‘magic bullet’ for preventing cognitive decline, study suggests

Evidence lacking for providers to recommend OTC supplements

Brain-boosting OTC supplements that claim to prevent cognitive decline may have ignited a growing industry, but they lack scientific proof to back those claims up. As researchers work to understand Alzheimer disease and related dementias, one area ripe for review has been the examination of dietary or herbal supplements in the prevention or delay of cognitive decline.

In the January issue of the Annals of Internal Medicine, researchers delved into this topic. They performed a systematic review of 38 qualifying trials from 2009 to 2017 that compared fatty acids, soy, ginkgo biloba, B vitamins, vitamin D plus calcium, vitamin C or beta carotene, multi-ingredient supplements, or other OTC interventions with placebo or other supplements. The research team concluded that the evidence showed that most of the OTC interventions studied had no proven benefit in preventing or delaying cognitive decline, mild cognitive impairment (MCI), or dementia in older adults.

“We really struggled to find signals of anything showing that there might be help,” said Mary Butler, PhD, lead author of the study and assistant professor at the University of Minnesota’s School of Public Health.

“When we did find signals, they tended to support the idea that stuff as it had been studied was not helping. It wasn’t showing a benefit.”

The review also found that only a small number of OTC supplements on the market had been studied for their effect on cognition and dementia.

Katelyn Alexander, PharmD, wasn’t surprised by the research findings. It would have been difficult to know if these patients would go on to develop more significant cognitive impairment, she said. Alexander also noted that Alzheimer disease and other cognitive disorders generally have an individualized progression.

“Patients all have differences in timing of onset and rate of decline of cognition. Therefore, successfully identifying a preventative solution within the relatively short timeline that most studies looked at would be very difficult to produce any concrete results or recommendations,” said Alexander, an assistant professor at the Bill Gatton College of Pharmacy at East Tennessee State University.

Some of the most common questions Alexander gets from her own patients relate to natural products and dietary supplements. The supplements and natural products that were part of the systematic review are consistent with those she receives questions about.

“As the Baby Boomer generation ages, they—in particular—have a focus on taking steps to stay in good health,” said Alexander, who has worked with older adult patients in the community throughout her career.

In the Annals paper, researchers said evidence was insufficient for health care providers to recommend any of the wide variety of OTC dietary supplements to patients with normal cognition or MCI.

 “There is no magic bullet. This is a complex phenomenon and a complex disease,” said Butler.

For the full article, please visit for the March 2018 issue of Pharmacy Today.