Investigators examined white matter hyperintensities in the brain to better understand if and how physical activity affects cognitive decline.
White matter hyperintensities (WMH) are commonly found on brain magnetic resonance imaging (MRI) scans in older adults. They are linked to cognitive impairment and increased risks of both stroke and dementia. Progression of white matter hyperintensities over time is known as a good indicator of cognitive decline. Experts believe that white matter hyperintensities are vascular in nature, and since physical activity improves cardiovascular health, physical activity may slow down the progression of white matter hyperintensities.
A recent French study published in the Journal of Nutrition, Health, and Aging examined the relationship between WMH progression and level of physical activity. The study analyzed data from a previous MRI and Alzheimer’s disease prevention clinical trial. Researchers included a total of 152 participants with a mean age of about 74 years. They excluded people with dementia, severe depression, or those who were limited in their ability to do basic daily activities.
At the beginning of the study, baseline MRI scans were conducted, and they measured the volume of white matter hyperintensities using automated software. Additionally, each participant completed a questionnaire about the frequency and duration of both leisure-time and household activities during the previous two weeks. Researchers then converted this information into a measure of continuous metabolic equivalent of task (MET)-minutes per week. They then categorized participants were into physical activity groups of low, moderate, and high. Follow-up MRI scans were taken at 12 months and at three years, and any changes in WMH volume and in physical activity were recorded. At the end of the study, they grouped the participants into one of five categories based on their baseline physical activity category: increase, decrease, sustained low, sustained moderate, or sustained high activity.
The investigators found that baseline physical activity was not significantly linked to WMH progression. However, participants who decreased their physical activity level over the three- year trial did tend to have greater WMH progression than those who maintained high activity levels. Although this observation was not statistically significant, maintaining a higher level physical activity remains important for overall health. Additional research in normal, healthy individuals may provide more information about physical activity and the progression of white matter hyperintensities in the future.
Written by Cindi A. Hoover, Ph.D.
Source: Moon SY, de Souto Barreto P, Cesari M, Chupin M, Mangin JF, Bouyahia A, Fillon L, Andrieu S, Vellas B. Physical activity and changes in white matter hyperintensities over three years. J Nutr Health Aging. 2017. https://doi.org/10.1007/s12603-017-0959-3