Exercise May Boost Immunity

Source: Tufts University
July 2, 2001 (Reviewed: December 23, 2002)

Exercise gives health a boost

Regular exercise provides a number of well-documented benefits, including stronger hearts, bones, and muscles. According to research published in Medicine & Science in Sports & Exercise, another item may be added to this list: strengthening the immune systems of older adults.

The aging immune system

Aging is often accompanied by a decrease in the effectiveness of the immune system. A weaker immune system can, in turn, make older adults increasingly vulnerable to infections and illnesses such as the flu or pneumonia.

Researchers have speculated that some of the decline in the immune system can be attributed to dietary deficiencies and/or a decrease in physical activity. To investigate this link, a group of Dutch scientists worked with 112 frail men and women for 17 weeks. The volunteers, whose average age was 79, all lived independently but required some outside assistance such as home care or home delivered meals.

The participants were divided into four groups. One group engaged in a moderately intensive, 45-minute exercise program twice a week; a second group consumed daily portions of food enriched with vitamins and minerals that are frequently under-represented in the diets of older adults; a third both exercised and ate enriched food; and a fourth did neither.

Study results

A skin test (designed to gauge participants' reaction to irritants) was used to measure the strength of the participants' immune system at the beginning and end of the 17-week study period. The researchers found that those individuals who participated in the exercise program showed a small, but meaningful increase in their immune response. While the group eating enriched foods experienced a beneficial increase in their blood levels of vitamins and minerals, there was no observed change in their immune response.

According to the authors, the body of research that focuses on exercise and immune function in older adults is small and inconsistent, and this study is the first to concentrate on a frail population. While additional research is needed, these results indicate that moderate exercise might help older adults, particularly frail older adults, fend off age-related declines in the immune system.

Benefits of exercise begin at any age

The participants in this study who exercised did not lift 50-pound weights, log miles on a treadmill, or engage in other rigorous activities to obtain favorable changes. Rather, they used equipment described as "inexpensive," in a program designed to maintain or improve mobility. And, none of the relatively aged volunteers were regularly active when they enrolled in the study, reinforcing the notion that it is never too late to start reaping the benefits of exercise and that modest efforts go a long way.

Source

• Immunity in frail elderly: a randomized control trial of exercise and enriched foods. A. Chin, M. Paw, N. De Jong, E. Pallast,  et al., Medicine & Science in Sports & Exercise, 2000, vol. 32, pp. 2005--2011

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