INDIANAPOLIS, Jan. 10 (UPI) -- Researchers from the Indiana University Center for Aging Research have found that body mass index, or BMI, influences how older adults respond to memory training.
The study found that memory training gave only one-third of the benefit to older adults with obesity as it did to older adults who were considered normal weight.
"These findings suggest that memory training is less beneficial for older adults with obesity but we really don't know why," Daniel O. Clark, Ph.D., associate professor of medicine and director of research and development at the Sandra Eskenazi Center for Brain Care Innovation at Eskenazi Health, and an investigator at the IU Center for Aging Research and Regenstrief Institute, said in a press release.
"There is growing evidence of a link between obesity status and brain function, including imaging studies reporting that obesity is associated with more rapid loss of hippocampal volume. So it's possible that actual capacity for memory gains is less for older adults with obesity."
For the study, scientists followed cognition in roughly 2,800 participants with an average age of 74 over a 10-year period, comparing cognitive performance in older adults with obesity to those who were overweight and normal weight, who did and did not receive memory training.
Of the 2,800 participants, three-quarters were women, three-quarters were white and one-quarter were African American.
The memory training emphasized improving verbal episodic memory through instruction and practice in strategy use.
"Other work has shown that weight loss can lead to improvements in memory function," Clark said. "Unfortunately we know from our own prior work, and that of others, that weight loss is difficult to achieve and maintain over the long term. We and others need to do more work to develop scalable and effective approaches to weight gain prevention and weight loss but we should also investigate programs with potential to protect memory function in the absence of weight loss for people with obesity -- a growing segment of our population."
Researchers found that BMI status affected the benefits from memory training, but there was no difference in training in reasoning or speed of processing in older adults related to BMI.
"Addressing dementia risk factors like obesity at any age is important as recent science indicates a lifecourse cumulative risk," Clark said.
The study was published in the journal of the Obesity Society.