This post is dedicated to a close friend of mine, a budding scientist with an aversion to yoga.
The benefits of yoga for cancer patients were plastered throughout the popular press recently, in anticipation of a presentation by Dr. Karen Mustian from the University of Rochester Medical Center at this year’s meeting of the American Society for Clinical Oncology in Chicago. This study enrolled 410 cancer survivors (96% female, 75% had breast cancer) suffering from moderate or worse sleep disturbance. The participants were randomized to standard monitoring versus a 4 week yoga intervention. Participants in the yoga program had improvements in sleep quality, fatigue, and various measures of Quality of Life compared with the control arm (no intervention). The benefit was significant enough to be covered by mainstream media outlets like CNN as well as web-based media like Breastcancer.org. ASCO president Douglas Blayney, MD, stated that the results are “readily applicable” for a huge patient population.
But wait. As we scientists often ask, do the results support the conclusions?
I think the answer is a resounding “Maybe.”
There is mounting evidence that cancer survivors benefit from participating in yoga programs. Although this study is the largest thus far reported, it is certainly not the first to show a benefit to yoga. Back in 2003 a study presented at the ASCO meeting showed that participation in a yoga intervention improved the Quality of Life of women newly diagnosed with breast cancer.
But is it yoga, per se, that helps? So far none of the studies have compared participation in yoga with any other exercise program. This study, for example, published in 2001, demonstrated that a home-based walking exercise program improved fatigue and other Quality of Life measures in women being treated for breast cancer. The studies cited on this page of the American Cancer Society’s website demonstrate a benefit to using a treadmill or an outpatient wellness program involving aerobic exercise, strength training, flexibility and relaxation. So maybe it’s exercise in general, and not specifically yoga, that helps cancer survivors live better.
Are the results of the yoga study “readily applicable” to a huge patient population, as suggested by Dr. Blayney? Again, I think the answer is “Maybe.” It depends on how you define “a huge patient population.” Dr. Mustian’s study is certainly applicable to the very large number of women diagnosed with breast cancer every year, but her study involved essentially only women with breast cancer. Given the variety of ways various cancers are treated, it may be premature to conclude that because yoga helped these women, that it would make a difference for young adults being treated with intensive chemotherapy for leukemia.
So what can we conclude? I think it is safe to conclude that some degree of exercise is beneficial for cancer patients, probably regardless of where they are in the course of their therapy. But before we can state that yoga is the best form of exercise, the right study has to be performed: patients need to be randomized to various forms of exercise, and research participants need to include men as well. Perhaps for a relatively inflexible man like me, the frustration of not being able to do “downward dog” will make yoga a poor choice, while the feeling of accomplishment associated with being able to last 5 more minutes on the treadmill will make that form of exercise a much better choice. Only a well-designed experiment can tell us for sure.
A new, old remedy for nausea
Cancer and Self-Image