Yoga's Benefits Explored

Women with breast cancer who practice yoga during radiation treatment receive a number of benefits that “appear to have long-term durability,” according to a study published in April in the Journal of Clinical Oncology.

Participants in the study, who had stage 0 to 3 breast cancer, were assigned to either a yoga program, a stretching protocol or a waiting list. While earlier studies of yoga showed it improved quality of life, this study demonstrated that it not only achieved that goal, but also provided physiological benefits.

Women in the yoga group attended up to three 60-minute classes per week, often one-on-one. The yoga program included exercises designed for women with breast cancer as well as breathing techniques, relaxation and meditation. In addition to quality-of-life measures, the level of the stress hormone cortisol was measured via saliva for three consecutive days. Stress levels are typically highest in the morning and then drop throughout the day.

“Research with breast and kidney cancer patients has shown that a less-steep cortisol slope, with levels not dropping by the end of the day, is associated with shorter survival,” says Lorenzo Cohen, director of the Integrative Medicine Program at MD Anderson Cancer Center in Houston, and a researcher on the study.

Participants in the yoga group showed a cortisol slope that was the steepest (meaning they had a greater decline in cortisol secretion) of the three groups.

“Having a steep cortisol slope may improve outcomes in cancer survivors,” says Cohen, who added that the slope remained steep one month later. Cohen explained that, while there have been a number of randomized clinical trials of yoga in cancer survivors that show it can reduce fatigue, sleep disturbances and mood problems, this study found that it can lead to improvements in the ability to engage in daily activities, and to better regulation of stress hormones.