Monday, October 22, 2007

Studies: Breast cancer survivors reap the rewards of fitness

A study published in the Journal of the American Medical Association said moderate exercise could cut the risk of dying from breast cancer in half. This study showed that for women with breast cancer, moderate exercise - three to five hours of walking a week at a 3.2 to 4.7 km/h pace - could cut the risk of dying from the disease by 50%.
Two other studies are touting the benefits of physical activity for breast cancer survivors with the suggestion that exercise can improve the functioning of the immune system, improve energy levels, and make survivors feel better about their bodies.
In the first study, presented at a meeting of the US Department of Defense's Breast Cancer Research Program, researchers compared blood markers for immune system health in 28 breast cancer survivors who had been assigned to an exercise program to those of 21 survivors in a non-exercise group. The women were between the ages of 29 and 71 and had undergone chemotherapy, which can affect healthy cells in addition to the cancerous ones.
"We know that chemotherapy-induced decreases in T cells (which fight infection) can persist for many years, and data from the literature suggest that, in the period immediately following chemotherapy, the surviving T cells may be weakened as well," said lead author Dr. Andrea Mastro. "That's why we're pleased to find evidence that appropriate exercise can help a breast cancer survivor's immune system bounce back after therapy."
The exercise program, which lasted for six months, consisted of a warm-up routine, resistance training using flex bands, and an aerobic segment. For aerobic activity, participants could choose between walking, riding an exercise bike, and using a treadmill.
In addition to the boost in T cells, exercisers saw a decrease in blood concentrations of IFN-a, an inflammatory substance indicating trauma. The non-exercisers, meanwhile, saw an increase. As well, the exercisers showed improvements in such fitness markers as endurance, upper body strength, and maximal oxygen intake. They also scored higher on questionnaires measuring quality of life, social well-being and other psychological factors.
In the second study, 86 women who had completed treatment for early-stage breast cancer were assigned to either 12 weeks of exercise counseling delivered via telephone or to a control group, where they received a phone call but no counseling. After 12 weeks, the counseling group reported significantly more physical activity.
While there were no significant differences among the groups in body fat or body mass index, women in the "exercise counseling" group reported higher energy levels and a greater reduction in fatigue. They also seemed to have more improvements in mood and body esteem.

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