Regular exercise benefits the heart, muscles, bones, and even the brain. New evidence from the University of California suggests that being aerobically fit - having a healthy heart and lungs - may reduce the mental decline that can occur in older adults. The findings are published in a recent issue of the Journal of the American Geriatrics Society.

About 350 healthy adults, ages 59 to 88 and free of dementia or mental impairment, participated in the study. They underwent a medical exam and interview to determine physical, social, and emotional health. Aerobic fitness was measured with a treadmill test. Mental function was assessed by a series of language, number, memory, and word tests, which included activities such as naming as many different animals that come to mind in 1 minute and identifying patterns within sequences of numbers and letters. Six years later similar tests were repeated.

Fitness gave a mental advantage

When the study started, mental functioning scores did not vary depending on fitness level. However, when the tests were repeated 6 years later, those who were less fit did not perform as well as they did initially. Meanwhile, the test scores of the more fit volunteers remained as high as they were at the study's start. The volunteers who were in good physical shape were better off in other ways too - they had more education and income and better self-rated health - which may also explain their higher scores. The scientists took these factors into account and concluded that fitness level, in part, was responsible for preserving mental capabilities.

Brain power

There are several means by which aerobic fitness could affect brain function. Physical activity may lower the risk of heart disease, high blood pressure, and diabetes - all medical conditions that can affect mental status, especially in older adults. Exercise may also increase blood flow to the brain or stimulate nerve growth. Or, exercise may simply improve overall health and better health may mean better cognitive function.

Advice to consumers

This study supports previous research that shows higher levels of activity may slow the rate of cognitive decline. Whether it's good for the mind because of a particular physiologic mechanism or because it simply lessens the impact of other diseases, physical activity is an important component of good health. Current physical activity guidelines call for at least 30 minutes of exercise on most, preferably all, days of the week. Inquire about group exercise options at your local senior center or health club. Exercising with other people provides support and motivation, and social interactions have been shown to benefit mental capacity.