Does Beta-Carotene Preserve Memory?
Study Shows Supplements May Help Keep Thinking Skills Sharp
Beta-Carotene and Memory continued...
The men were all in good health when they started the studies. Those who had taken part in the original study were about age 73 when the sequel study began; the new recruits were about 56 on average.
The men were followed up through 2003, completing yearly questionnaires about their health and their compliance with taking the pills. Their cognitive functioning was tested by telephone at least once between 1998 and 2002.
"The focus was on verbal memory," Grodstein tells WebMD. For instance, researchers would read a list of words and ask the participants to read them back immediately and again 20 minutes later.
"We found [in] the men who had been on beta-carotene long term -- 18 years [on average] -- their memory was significantly better than the placebo group," Grodstein says. In the 18-month interval between studies, she says, some of the men in the original study may have stopped the beta-carotene temporarily.
Grodstein says she would categorize that improvement as modest. Even so, she says, modest improvement may lead to substantial differences in a person's eventual risk of getting dementia. Taking the supplements short term had no effect, she says.
The study is published in the Nov. 12 issue of Archives of Internal Medicine. The research was supported by grants from the National Institutes of Health, BASF Corp. (which makes a beta-carotene supplement), and others.
The unusual study design, in which some participants were carried over from the other study and kept their original assignments, may have affected the results, says Peifeng Hu, MD, staff geriatrician at Santa Monica-UCLA Medical Center & Orthopaedic Hospital, Calif. Hu is also assistant professor of geriatric medicine at the University of California Los Angeles David Geffen School of Medicine.
The findings don't warrant recommending supplements of beta-carotene, he says. "I would not change my practice based on this study," says Hu, who found in his own research that high blood levels of beta-carotene (not necessarily from supplements) reduced the risk of cognitive decline in people genetically predisposed to get Alzheimer's. His study findings were published in 2006 in the Journal of Gerontology.