Healthier lifestyle associated with fewer dementia-related brain proteins in PET scans

Having a lower BMI, eating healthier foods and getting more physicial activity could be associated with fewer PET scan-detectable amyloid and tau proteins in the brain in adults with subjective memory impairment and mild cognitive impairment, according to a new study.

Amyloid and tau proteins are the tangles found in the brains of Alzheimer’s disease patients. Researchers, who published their findings in the American Journal of Geriatric Psychiatry, wanted to see if these protein tangles could be connected with lifestyle habits among people who had cognitive difficulties but did not (or not yet) suffer from Alzheimer’s disease or other types of severe dementia. The study authors explained that these positive behaviors correlated with fewer memory problems, but wanted to see if the physical indicators of protein tangles were also affected.

The study followed 24 people with subjective memory impairment and 20 people with mild cognitive impairment. It compared aspects of their lifestyles against the levels of amyloid and tau protein tangles found in their brains through PET scans. All subjects were all between ages 40 and 85.

Cognitive states were measured through excluding dementia criteria from the DSM IV tests. Their physical activity levels were measured using the International Physical Activity Questionnaire and sorted into “higher” or “lower” activity levels. They were then to explain how often they ate foods related to a Mediterranean-style diet, such as fruits, vegetables, fish and olive oil. Presence of protein tangles were determined through PET scans and brain MRIs.

The researchers called the associations between these healthier lifestyle markers and protein markers “moderate but significant.” A healthy diet was associated with fewer of these proteins in the brain among all the participants. And among the participants with moderate cognitive decline, a lower BMI and more physical activity were associated with fewer of these proteins in the brain.

The authors said these findings are in line with many other studies looking more at patients with dementia than pre-dementia patients and is more evidence in favor of advocating for healthy diets, physical activity and lower BMI in older adults to avoid cognitive decline.