Yoga Yields Weight Loss in Middle Age
Benefits may be linked to 'mindful' changes in health habits, experts say
FRIDAY, Aug. 5, 2005 (HealthDay News) -- The ancient practice of yoga may do more than just improve strength and flexibility -- it could also help people shed extra pounds in middle age, new research suggests.
Investigators report that overweight 45- to 55-year-olds who regularly practiced yoga lost five pounds on average over the course of a decade. At the same time, normal-weight yoga practitioners gained three fewer pounds than those who didn't practice yoga during this same 10-year period.
The study, conducted by researchers at the Fred Hutchinson Cancer Research Center in Seattle, is the first to examine yoga's impact on weight loss. It appears in the July/August issue of Alternative Therapies in Health and Medicine.
"I was very surprised with the results. Considering that people gain about a pound a year during this time, this is pretty substantial," said lead researcher Alan R. Kristal, associate head of the Cancer Prevention Research Program at the Hutchinson Center and a professor of epidemiology at the University of Washington. "Even the best dietary and behavioral approaches to weight loss are not all that effective. Now, with yoga, we have one more tool that may help with weight loss," he said.
With 30 percent of American adults obese and almost 65 percent of them overweight, looking to old techniques for new solutions to weight management makes sense. To examine the relationship between weight loss and yoga, the study surveyed 15,500 healthy men and women aged 53 to 57. Participants were queried on their weight history and physical activity (including yoga), among other things, beginning at age 45.
Just 132 of the people surveyed said they practiced yoga regularly for at least four years. However, overweight yoga practitioners lost about 5 pounds on average during the 10-year period, while those who did not practice yoga gained an average of 13.5 pounds. People who were normal-weight and regularly practiced yoga gained three fewer pounds during this period of life than those who didn't do yoga (9.5 pounds compared to 12.6 pounds).
Kristal said he isn't certain how yoga helps promote weight loss and maintenance, particularly since only vigorous yoga would burn enough energy to meet the American College of Sports Medicines guidelines for weight management. However, he speculated that yoga could be indirectly beneficial by encouraging healthier eating and exercise habits. For example, since yoga teaches body awareness and encourages physical discipline, it helps a person know when they're full and promotes a general sense of well-being, he said.
Dr. Janine Blackman, the medical director of the University of Maryland Center for Integrative Medicine, has another theory: the "mindful" nature of yoga creates a healthier response to stress, which in turn prevents stress-driven eating and lowers stress hormones.
"Middle age is a full time in life," she said. "A better response to this stress can lower cortisol and other stress hormones, which helps physiologically. If cortisol is elevated, you're more likely to have insulin resistance, which is central to obesity."
Whatever the reasons, both Blackman and Kristal agreed that more research is needed, particularly to counter the study's limitations. For example, people in this study didn't report the type of yoga they practiced -- that's important, since the physical intensity of yoga varies with specific techniques. The survey was also self-reported, relying on people's memories and assuming they were honest. Kristal hopes a future observational study will help fill in these gaps and that, eventually, a large, randomized trial will be conducted.
In the meantime, Blackman, who recommends gentle yoga to her patients, said she will continue to do so.
"Gentle yoga is a great way to ease into an active life, especially since overweight people are already less likely to exercise because it hurts," she said. "Now there's another reason to encourage yoga, in terms of weight loss, which is a big carrot for people. Thanks to this study, I have evidence to back my personal stories."
For more on yoga and other natural healing techniques, head to the National Center for Complementary and Alternative Medicine.