Brain atrophy, also called cerebral atrophy, can develop when there is loss of grey matter (brain cells) or white matter (brain cell connections). Brain atrophy causes shrinkage of the brain and an overall reduction in brain size. Brain atrophy is more common with increasing age and several medical conditions such as epilepsy, strokes, Alzheimer’s dementia, multiple sclerosis, cerebral palsy, traumatic brain injury, Huntington’s chorea, and Parkinson’s disease. Brain atrophy can cause cognitive deficits that range from mild memory loss to severe dementia and aphasia. We have previously discussed the finding that physical fitness in midlife delays the onset of chronic medical conditions in later life and that physical activity decreases inflammatory markers associated with cardiovascular disease and aging. Recent research provides evidence that physical activity can protect against brain atrophy in older age.
Researchers, led by Dr. Alan J. Gow from the University of Edinburgh, have found that physical activity was associated with less brain atrophy and white matter lesions in an elderly population. The results of their study were published online in the journal Neurology. The researchers studied the association between brain atrophy and physical activity in a longitudinal study using 691 study participants enrolled in the Lothian Birth Cohort 1936 study. The researchers used self-reported leisure and physical activity at age 70 years and correlated it with structural brain changes using brain imaging at age 73 years. The researchers found that physical activity was associated with less atrophy and white matter lesions, but not with socialization.
The authors wrote, “Physical activity was associated with higher [fractional anisotropy], gray and [normal-appearing white matter] volumes, lower [white matter lesion] load, and less brain atrophy 3 years later. An effect on atrophy, gray matter volume, and [white matter lesion] load from the computational measures, and rated atrophy, remained after inclusion of age, sex, social class, prior cognitive ability, and self-reported health measures”.
The authors also wrote, “Indeed, reduction in cardiovascular risk profile is one of the key mechanisms proposed as underlying the effect of physical activity on cognitive aging.3,8 The possibility that physical activity is a proxy for better general health should not be overlooked…The indicative benefit of physical activity deserves further study, including randomized control trials of physical interventions, to rule out alternative causal mechanisms whereby physical activity may indicate better general health, including lower cardiovascular risk, which is itself associated with fewer [white matter lesion] and less atrophy ”.
The authors concluded, “The neuroprotective effect of physical activity is supported by the current analyses, in agreement with ‘indications that regular exercise promotes the structural … integrity of the CNS and, thereby, counteracts age-related decline.’ These indicative findings are important to those developing interventions designed to reduce or delay cognitive decline in the elderly, although ultimately a causal effect can only be demonstrated in randomized control trials of physical activity. There was, however, no support for a beneficial effect of more intellectually challenging or socially orientated activities”
The health benefits of exercise and physical activity are well documented. As this study shows, physical activity may help to prevent and delay the onset of brain atrophy in the elderly. This study identifies an association between decreased white matter lesions and brain atrophy and exercise, but does not prove a cause and effect relationship. It may be that individuals who are engaged in exercise are healthier overall and thus have less brain atrophy. Future studies should work to identify a possible mechanism for this finding. Regardless, it’s always a good idea to engage in regular exercise and physical activity.
Alan J. Gow et al. “Neuroprotective lifestyles and the aging brain: Activity, atrophy, and white matter integrity” Neurology published online October 23, 2012 vol. 79 no. 17 pages 1802 – 1808.