Researchers from the University of South Florida, in Tampa, and from Fudan University, in Shanghai, conducted an 8-month randomized, controlled trial to compare changes in brain volume and cognition resulting from four interventions: tai chi, walking, social interaction and no intervention. Subjects were 120 older Chinese adults; they were divided into four groups, each assigned to one intervention.
Investigators collected data from MRIs and from tests of cognitive abilities at baseline, after about 20 weeks and after 40 weeks to assess changes resulting from the interventions. Data analysis showed strongest improvements among those who did tai chi. Members of the social interaction group also experienced an increase in brain volume but did not show as much improvement in cognition. The walking group as a whole showed no significant improvements in brain volume, but further analysis found that among walkers who walked faster, cognitive test scores were higher than they were among those who walked more slowly.
“No intervention” participants experienced a loss of brain volume over the study period.
“The ability to reverse [the trend of brain volume loss prior to cognitive deterioration and the onset of dementia] with physical exercise and increased mental activity implies that it may be possible to delay the onset of dementia in older persons through interventions that have many physical and mental health benefits,” said lead author James A. Mortimer, PhD, professor of epidemiology and biostatistics at the University of South Florida College of Public Health. “Epidemiologic studies have shown repeatedly that individuals who engage in more physical exercise or are more socially active have a lower risk of Alzheimer’s Disease. The current findings suggest that this may be a result of growth and preservation of critical regions of the brain affected by this illness.”
More research—with larger numbers of people, over a longer period of time and with a more diverse population—is warranted.