The benefits of aerobic activity are well documented regarding overall physical health and well-being. Many studies have also shown an association between aerobic activity and cognitive function, but the mechanism was unclear. Now, we may know the reason.

A new study presented at the annual meeting of the Radiological Society of North America reported that adults who exercise regularly exhibit increased blood flow to the brain, as well as more small vessels in the brain, compared with those who do not exercise regularly. This study posits that the differences in blood flow between exercisers and non-exercisers could explain why physical activity prevents cognitive decline as people age.

The researchers at the University of North Carolina at Chapel Hill evaluated 12 adults, aged 60 to 76 years old. Six of the subjects reported participating in aerobic exercise for 3 or more hours each week for the past 10 years. The remaining 6 subjects reported exercising less than 1 hour each week. The researchers conducted MRI scans and magnetic resonance angiography (MRA) of the patients’ brains and created 3-D models of the blood vessels. According to these models, the inactive group experienced more unpredictable blood flow through the brain, as well as possessing fewer small blood vessels than the active group.

As we age, our body — and brain — undergoes changes that can lead to physical and cognitive decline. Among these is the narrowing and loss of small blood vessels. Exercise reverses this blood vessel destruction in other parts of the body, so it is not surprising that it may have the same effect in the brain.

To date, most studies examining exercise and cognitive function focused on aerobic activity, and used prospective or retrospective study designs. Randomized clinical trials are needed to fully assess the impact of exercise on cognitive decline. Likewise, resistance exercise and other types of physical activity need to be considered, in addition to aerobic exercise, as beneficial in cognition. We already know that resistance exercise reduces morbidity and mortality in senior citizens, including decreased fall and fracture risk, and overall physical disability associated with aging.

Physical activity is valuable in the healthy aging process. Regular activity not only improves cardiovascular, respiratory, and muscular fitness, but also has positive effects on motor function, cognitive speed, memory function, and auditory and visual attention. Exercise also significantly improves mood in seniors and improves overall quality of life. The newest research demonstrates, once again, that the benefits of regular exercise are limitless. Routine physical activity should be encouraged for most patients, as part of a healthy aging process.

References

Angevaren M, Aufdemkampe G, Verhaar HJ, Aleman A, Vanhees L. Physical activity and enhanced fitness to improve cognitive function in older people without known cognitive impairment. Cochrane Database Syst Rev. 2008(3):CD005381.

Angevaren M, Aufdemkampe G, Verhaar HJ, Aleman A, Vanhees L. Physical activity and enhanced fitness to improve cognitive function in older people without known cognitive impairment. Cochrane Database Syst Rev. 2008(2):CD005381.

A. K Brown, T. Liu-Ambrose, R. Tate, S. Lord (2008). The Effect of Group-Based Exercise on Cognitive Performance and Mood in Seniors Residing in Intermediate Care and Self-Care Retirement Facilities: A Randomized Controlled Trial British Journal of Sports Medicine DOI: 10.1136/bjsm.2008.049882

T. Liu-Ambrose, M. Donaldson (2008). Exercise and Cognition in Older Adults: Is there a Role for Resistance Training Programs? British Journal of Sports Medicine DOI: 10.1136/bjsm.2008.055616

Rahman F, Smith J, Bullitt E, Katz L, Marks B. Relationship of exercise to cerebral vasculature and blood flow in older adults. Paper presented at: Radiological Society of North America; December 1, 2008; Chicago, IL.