To gauge the participants' inflammation levels, the scientists measured the activation of three proteins in the blood that are markers of inflammation – called pro-inflammatory cytokines. They generated the protein activity by injecting a compound that stimulated an immune response. The proteins are interleukin-6 (IL-6), interleukin-1 beta (IL-1B) and tumor necrosis factor-alpha (TNF-a).
At the three-month point immediately after the yoga sessions ended, all three pro-inflammatory cytokine levels were lower, on average, in the yoga group compared to the non-yoga group: TNF-a by 10 percent, IL-6 by 11 percent and IL-1B by 15 percent.
"We were really surprised by the data because some more recent studies on exercise have suggested that exercise interventions may not necessarily lower inflammation unless people are substantially overweight or have metabolic problems," Kiecolt-Glaser said. "In this group, the women didn't lose weight, but we saw really marked reductions in inflammation. So this was a particularly striking finding biologically."
A secondary analysis showed that more frequent yoga practice produced larger changes in fatigue, vitality and depressive symptoms as well as between an average 4 to 6 percent reduction in two of the three pro-inflammatory cytokines. The yoga group also reported significantly improved sleep compared to the control group.
"Yoga has many parts to it – meditation, breathing, stretching and strengthening. We think the breathing and meditation components were really important in terms of some of the changes we were seeing," Kiecolt-Glaser said.
Revisiting the participants again at the six-month point, three months after the intervention was complete, the researchers discovered that health measures in the yoga group had continued to improve in that window of time: Fatigue was 57 percent lower and inflammation was between 13 and 20 percent lower than the non-yoga group.
"We think improved sleep could be part of the mechanism of what we were seeing. When women were sleeping better, inflammation could have been lowered by that," Kiecolt-Glaser said. "Reducing fatigue enables women to engage in other activities over time. So yoga may have offered a variety of benefits in addition to the yoga exercises themselves."
There are few experts who debate the physical benefits of yoga. Regular practice can not only improve your balance, it can help you become stronger and more flexible as well. But some say linking yoga to actual medical benefits is a real "stretch." That is, until now. Researchers at The Ohio State Comprehensive Cancer Center -- James Cancer Hospital and Solove Research Institute have completed the largest study ever of the medical benefits of yoga, and their findings are significant.
"We looked at blood samples of some 200 breast cancer survivors over the course of five years, and found that even modest practice of yoga could have huge benefits," said Janice Kiecolt-Glaser, Ph.D., who led the study.
"Six months after taking up yoga, we found in these patients that fatigue dropped 57 percent, and inflammation markers in the blood dropped up to 20 percent," she said. The more a woman practiced yoga, the better her results.
The study is published in the American Journal of Clinical Oncology.
(Photo Credit: The Ohio State Comprehensive Cancer Center - James Cancer Hospital and Solove Research Institute)
Researchers at The Ohio State University Comprehensive Cancer Center have found a link between yoga and lower rates of inflammation in breast cancer survivors. Scientists followed nearly 200 breast cancer survivors for five years and found that six months after taking up yoga, fatigue levels dropped 57 percent and inflammation dropped as much as 20 percent.
(Photo Credit: The Ohio State Comprehensive Cancer Center - James Cancer Hospital and Solove Research Institute)
Source: Ohio State University