Healthy habits may shield against dementia even after brain changes

Healthy lifestyles are associated with better cognitive function in older adults — even those whose brains show signs of dementia, according to research published in JAMA Neurology last month. The study suggests a healthy lifestyle could buffer older adults against cognitive decline and boost their “cognitive reserve.”

Researchers used data from the Rush Memory and Aging Project, a long-term study that looked at patients’ lifestyles and health and analyzed autopsy data from 1997 to 2022.

Scientists examined demographic, lifestyle and postmortem information on 586 patients, including details about their diets, their cognitive functioning before death, and lifestyle factors such as alcohol intake and physical activity.

The patients, 70.8 percent of whom were female, lived to a mean age of 90.9. Their brain autopsies were examined for physical signs associated with dementia, including a buildup of amyloid plaques, which disrupt cell function in the brain and are associated with Alzheimer’s disease.

Among all the patients, higher healthy lifestyle scores in five domains — diet, late-life cognitive activity, physical activity, smoking cessation and low alcohol intake — were associated with better cognitive function before their deaths. The association held even when the autopsies showed signs of brain changes consistent with dementia.

Overall, just a one-point increase in lifestyle score was associated with better cognition.

The analysis suggests a healthy lifestyle could boost people’s “cognitive reserve,” the researchers write, allowing patients to stay sharp despite changes in their brains.

Lifestyle factors like diet and nutrition might protect the brain from inflammation and oxidative stress, the researchers write. Most of the patients in the study sample were White, and the researchers note that the lifestyle information was self-reported.

The analysis “is a crucial step forward” in addressing questions about the connections between lifestyle, brain changes and cognition, write a pair of researchers in a related editorial in JAMA Neurology. They suggest lifestyle factors be prescribed alongside Alzheimer’s disease medications and call for more studies that look at dementia risk reduction among diverse groups.