March 4, 2014
By Honor Whiteman
Radiation therapy is one of the main treatments for cancer, and one of the most common side effects of the treatment is fatigue. But new research from the University of Texas MD Anderson Cancer Center suggests that for breast cancer patients undergoing radiation therapy, yoga may combat this side effect by regulating stress hormones, improving quality of life beyond treatment.
The research team, led by Prof. Lorenzo Cohen, recently published the study findings in the Journal of Clinical Oncology.
Yoga is an ancient exercise that originated in India around 5,000 years ago. The activity combines physical postures, breathing exercises, relaxation techniques and meditation, and it has been associated with other health benefits.
Last year, Medical News Today reported on a study suggesting that yoga can help lower blood pressure, while a 2012 study suggested that the exercise may help prevent adolescent mental problems.
To assess whether yoga could provide health benefits for breast cancer patients, the researchers analyzed 191 women with stages 0-3 of the disease.
Researchers say yoga could combat fatigue for breast cancer patients undergoing radiation therapy and improve overall quality of life during and after treatment.
All women were randomized into three groups: yoga, simple stretching or no instruction in yoga or stretching.
The women in the yoga or simple stretching groups were required to attend 1-hour classes for 3 days a week during the course of their 6-week radiation treatment. All sessions were tailored to breast cancer patients.
During the study period, the women were asked to report on their quality of life, including levels of fatigue and depression, sleep quality and how they were able to function on a daily basis.
The researchers conduced electrocardiogram (ECG) tests and took saliva samples from the women at the baseline of the study, the end of their radiation therapy and at 1, 3 and 6 months after treatment. This was to measure the participants' levels of cortisol - known as the "stress hormone."
Yoga reduced women's cortisol levels and fatigue
Results of the study revealed that the women who took part in the yoga sessions showed the sharpest decline in cortisol levels of all the groups, suggesting that yoga was able to regulate the stress hormone.
The investigators say this finding is important because increased stress hormone levels during the day - known as blunted circadian cortisol rhythm - have been associated with worse breast cancer outcomes.
Furthermore, the researchers found that women in the yoga group reported a reduction in fatigue, whereas the women in the other two groups did not. The women in the yoga group also reported better general health and functioning at 1, 3 and 6 months after radiation treatment.
These women also reported being able to find meaning in their experience of illness, while women in the other two groups did not.
"Combining mind and body practices that are part of yoga clearly have tremendous potential to help patients manage the psychosocial and physical difficulties associated with treatment and life after cancer, beyond the benefits of simple stretching."
Additionally, he says research has shown that adopting a yoga practice after cancer treatment can help breast cancer patients cope with their experience.
"The transition from active therapy back to everyday life can be very stressful as patients no longer receive the same level of medical care and attention," explains Prof. Cohen. "Teaching patients a mind-body technique like yoga as a coping skill can make the transition less difficult."
The research team is now in the process of a phase III trial of women with breast cancer, with the aim of understanding how yoga can improve physical function, biological outcomes and quality of life after radiation therapy.
This is not the first study to find a link between yoga and health benefits for breast cancer patients. Medical News Today recently reported on a study suggesting that for breast cancer survivors, yoga can reduce symptoms of fatigue and inflammation.