Physical activity associated with slower cognitive decline in people with high levels of tau protein
Engaging in high or medium levels of physical activity was associated with slower rates of cognitive decline in people with high or low levels of tau, compared to those with little physical activity. Led by researchers at Rush University Medical Center, the findings were published in JAMA network open August 11. The researchers noted that measuring levels of tau, a protein characteristic of Alzheimer’s disease, in the blood could help identify people who might benefit from early intervention to slow cognitive decline.
In people with Alzheimer’s disease, the abnormal buildup of tau becomes tangled in the brain. Higher levels of tau are associated with cognitive decline and increased problems with memory and thinking. Research has shown that physical activity can help slow cognitive decline, but it was not known whether levels of physical activity were associated with slow cognitive decline in people who have high levels of tau.
A team of researchers used data from 1,159 seniors who participated in a large study called the Chicago Health and Aging Project (CHAP) between 1993 and 2012. CHAP researchers assessed cognitive function using various tests, asked participants about their physical activity, and collected blood samples from participants, who did not have Alzheimer’s disease at the start of the study. In 2019, researchers measured tau concentrations in blood samples, which had been frozen, and compared rates of cognitive decline in people with high and low tau concentrations and high levels of physical activity, medium and weak.
The researchers found that among participants with high tau levels, those who reported average physical activity levels had a 58% slower rate of cognitive decline than participants with low physical activity levels. Those who reported high levels of physical activity had a 41% slower rate of cognitive decline than those who reported low levels of physical activity. For participants with low tau concentrations, those with high physical activity levels exhibited significantly slower cognitive decline than those with medium or low physical activity levels.
The study had some limitations. It only included white and African American participants, and it measured the duration but not the intensity of physical activity. The researchers also note that the rate of cognitive decline was sometimes lower in participants with average physical activity levels than in those with high physical activity levels; the reasons for this variation merit further study.
The results suggest that measuring proteins – such as tau – in the blood could help identify people who would benefit from increased physical activity or other behavioral changes that could help slow cognitive decline. Measuring these proteins could also help future studies measure the benefits of behavior changes in those most at risk of developing Alzheimer’s disease.
This research was funded by NIA grants R01AG03154, R01AG051635, RF1AG057532 and R01AG058679.
These activities relate to NIH AD + ADRD Research Implementation Milestone 9.M, “Developing Diagnostics / Biomarkers in Asymptomatic Individuals” and to NIH AD + ADRD Research Implementation Milestone 9.F. NIH, “Initiate studies to develop minimally invasive biomarkers for the detection of cerebral amyloidosis, AD and the pathophysiology of AD-related dementias. “
Reference: Desai P, et al. Longitudinal association of total tau concentrations and physical activity with cognitive decline in a sample population. JAMA network open. 2021; 4 (8): e2120398. doi: 10.1001 / jamanetworkopen.2021.20398.