The long-term use of beta carotene supplements—the chemical that gives carrots and sweet potatoes their orange color—may reduce the risk of cognitive decline in men, according to a report released in the Nov. 12 issue of the Archives of Internal Medicine.
Researchers found that oxidative stress, which damages brain cells, is a major contributor to the aging of the brain and associated cognitive decline. Beta carotene, a known antioxidant, was used to prove such a link during the 18-year study.
“This study proves that achieving changes in memory will likely require long-term interventions, rather than short-term fixes,” said Francine Grodstein, the leading researcher of the study and an associate professor at the Harvard School of Public Health (HSPH).
Grodstein and colleagues observed the effects of beta carotene on nearly 6,000 men, over both an 18 year span and a one year span.
In the beginning of the study, participants took either daily 50 milligram beta carotene supplements—the equivalent of eating nine raw carrots—or placebos. The subjects were then tested for general cognition, verbal memory, and category fluency. “This study, based on a well conducted, long term randomized trial, provides proof of principle that we can influence the likelihood of cognitive decline through long-term life style changes,” said HSPH Professor Meir Stampfer.
Despite the possible positive effects, Grodstein said he is hesitant to recommend beta carotene supplements for everyone.
“Beta-carotene has both risks and benefits,” Grodstein said. “The decision to take supplements or not is an individual one.”
One such risk is that beta carotene supplements have been shown to increase the risk of lung cancer among smokers and people who are in contact with asbestos, according to Grodstein.
The Alzheimer’s Association, an organization that conducts research on behalf of those afflicted with dementia, does not currently recommend specific supplements for cognitive health.
“We are always encouraged by research that may eventually yield promising results,” said Betsy Percoski, a vice president of communications & public affairs for the association’s Massachusetts chapter. “At this time, the clearest evidence we have is that a heart-healthy lifestyle of regular moderate exercise and a low fat healthy diet are the best preventative steps to slow the symptoms of Alzheimer’s disease.”
Nevertheless, Grodstein said that the study revealed the importance of small choices.
“Although long-term interventions may be required, it is reassuring to know that we can maintain memory with aging via fairly modest lifestyle changes” he said. [SEE CORRECTION BELOW]
CORRECTION: Due to an editing error, the Nov. 29 news article "Beta Carotene May Boost Brain" incorrectly referred to Harvard School of Public Health associate professor Francine Grodstein as male. In fact, Grodstein is female.