by Stacy D. Hunter, Ph.D.
Twenty-six postures, 90 minutes and 105-degree heat and humidity have people flocking into Bikram yoga studios worldwide. This mindbody practice has amassed a following of tens of thousands, with more than 300 studios operating in the U.S. and hundreds more spanning six continents.
Perhaps the reason that this yoga is spreading like wildfire is the seemingly endless stream of testimonials from practitioners claiming weight loss and reductions in blood pressure, cholesterol and other disease symptoms and ailments ranging from fibromyalgia to diabetes. Some diabetics have even reported controlling their blood glucose levels without having to use insulin.
While the testimonies are mounting, not many studies have attempted to scientifically document these claims. There are only six published studies on Bikram yoga and two are case reports of individuals that experienced adverse reactions during classes.
A recent study published in the Journal of Bodywork and Movement Therapies revealed that adults at risk for Type 2 diabetes reduced their blood glucose levels with just eight weeks of practice. Conducted at the University of Texas in the Cardiovascular Aging Research Laboratory, this study had participants practice Bikram yoga three times weekly and found that their blood glucose responses during a glucose tolerance test were lowered as a result. This test is often used in the diagnosis of diabetes and includes a fasting blood glucose measurement followed by multiple measurements after the ingestion of a sugar-containing beverage. Those at risk for Type 2 diabetes have impairments in glucose metabolism, which lead to higher glucose responses to the beverage than healthy adults.
While multiple studies have shown improvements in glucose responses with traditional exercise (i.e. treadmill walking), very few have shown the same with yoga. These groundbreaking results are the first to document what diabetic Bikram practitioners have been claiming for years. While the outcomes of this study were positive and no health emergencies occurred, it is still necessary to use caution and consult with a physician before beginning Bikram yoga or any other exercise program, especially in the presence of pre-existing conditions.
What makes this style of yoga beneficial for metabolism could be the heat. Endocrinologist Philip L. Hooper, M.D., was the first to document the benefits of heat in diabetic patients using six days per week of hot-tub therapy over a three-week period. “As standard pharmacologic therapies are presently inadequate, I focused on trying to mimic the beneficial effects of exercise by simply warming the body,” says Dr. Hooper, of the University of Colorado Department of Endocrinology, who noted that “the results exceeded my expectations with improvements in fasting glucose, a 1 percent drop in A1c, a trend toward weight loss and relief of neuropathic symptoms.”
Although this study received some backlash from the medical community because of its use of an unconventional approach to diabetes treatment, other studies have since found similar benefits of heat therapy over time. Bikram Choudhury, founder of the Bikram yoga series, says of his early years of teaching in Japan that the postures were easier to perform when the room temperature was increased. He then made it an essential part of the practice. Choudhury must have been on to something as research has shown that heat not only loosens the muscles making them more yielding to the postures, but also improves metabolism and circulation.
While testimonials can be persuasive, this data-driven society needs proof. There has been an increased interest in Bikram yoga research from scientists and medical professionals alike. Time will tell what other Bikram yoga health benefits can be documented scientifically. For now, it appears that it is an effective strategy for maintaining healthy glucose levels.
Stacy D. Hunter, Ph.D., is the research director for PURE Action, a nonprofit organization in Austin, devoted to funding yoga research. For more information, visit PureAction.org.