By Andrew M. Seaman
NEW YORK (Reuters Health) - Participating in yoga classes after treatment for breast cancer was linked to reduced fatigue and inflammation and increased vitality among women in a new study.
Researchers found that breast cancer survivors who took 12 weeks of yoga classes ended up with reduced inflammation and felt less tired after six months, compared to a similar group of women who didn't take yoga classes.
"This may be a way to provide a good activity that also has other benefits," Janice Kiecolt-Glaser, the study's lead author, told Reuters Health.
Kiecolt-Glaser is an investigator at The Ohio State University Comprehensive Cancer Care Center and the Institute for Behavioral Medicine Research in Columbus.
She and her colleagues write in the Journal of Clinical Oncology that cancer survivors are twice as likely to have poor health and more disability, compared to people without a history of cancer.
That may be partially explained by less exercise and activity during and after cancer treatment, which may increase inflammation throughout the body. Chronic inflammation has been tied to increased risks for death and a number of health disorders.
Previous research has also found that inflammation tends to be elevated among cancer survivors and people who don't do a lot physical activity.
Yoga may be one way to get breast cancer survivors moving again, because its intensity can be tailored to an individual's limits. Yoga has also been linked to reduced fatigue among cancer survivors through better sleep (see Reuters Health story of August 30, 2013 here: http://reut.rs/16Xrk56
To see whether yoga had an effect on inflammation, mood and fatigue, the researchers recruited 200 breast cancer survivors, who finished their treatments at least two months before the study began in 2008.
The women were randomly assigned to one of two groups that either participated in two weekly 90-minute yoga sessions for 12 weeks or were put on a waiting list and told to avoid yoga.
The women's blood was analyzed for indications of inflammation. They also answered a series of surveys and questionnaires to measure their fatigue, vitality and mood.
At the end of 12 weeks, the researchers found that women taking the yoga classes scored higher than the comparison group for vitality. But there were no significant differences between the groups in measurements of mood, fatigue or inflammation.
Another three months after the yoga classes ended, however, women in the yoga group were less fatigued and had higher vitality scores than women in the comparison group.
For example, before anyone did yoga, both groups of women scored about 14 on a fatigue scale of 0 to 30, where higher scores indicate greater fatigue. At the end of the study, the average score among women in the yoga group was five, versus about 13 among women in the comparison group.
There was no difference between the groups in mood, but Kiecolt-Glaser said the women weren't depressed enough at the start of the study to leave room for improvement.
In addition to feeling less tired, the researchers found that at six months the indicators of inflammation in the yoga participants' blood samples were between 13 percent and 20 percent lower than those in the comparison group.
"My best guess is that when women are sleeping better they're less fatigued and their inflammation goes down," Kiecolt-Glaser said, adding that the more often the women did yoga weekly, the better their results.
While Kiecolt-Glaser said the women in the study would notice a difference in their fatigue after the study, she added that it would be difficult to know if the lower inflammation led to noticeable differences. That would require longer studies.
Karen Mustian, who was not involved in the study but has researched yoga among cancer survivors, said it's also important to find out how yoga affects the body.
"We really need to be able to drill down and understand how it works to be able to more accurately prescribe these interventions," said Mustian, who is from the James P. Wilmot Cancer Center at the University of Rochester Medical Center in New York.
She also said yoga can be recommended to breast cancer survivors as long as they're aware of some caveats, including that they should pick a low-to-moderate intensity yoga, understand their physical limitations and do their research to find a credentialed and trained yoga instructor.
"Yoga is certainly an excellent intervention to try when women are feeling fatigued post treatment," Kiecolt-Glaser said. "But in general even for women and men who aren't cancer survivors, it may be an excellent intervention if they're feeling fatigued and (have) declined to take part in something more vigorous."
SOURCE: http://bit.ly/1aKq5Mb Journal of Clinical Oncology, online January 27, 2014.