Despite the widespread belief that taking slow, deep breaths can relieve the discomfort of hot flashes during menopause, women in a clinical trial found no benefit from the technique.
The lead author of the study, which was published online in the Journal of General Internal Medicine, said that based on the results, she would not encourage women to look to slow breathing as a treatment for hot flashes.
"I would actually rule this out. One of the reasons is, I think we need to not tell women to use things that are not helpful, because it delays them finding treatments that are helpful," Dr Janet Carpenter, a professor at Indiana University's School of Nursing, told Reuters Health.
Slow breathing, also called paced respiration, involves taking six to eight breaths every minute. The method is commonly encouraged for relaxation, and is thought to affect the autonomic nervous system. The North American Menopause Society and many physicians encourage women to practice the technique twice a day for 15 minutes at a time, and also at the onset of a hot flash.
Past studies showing that slow breathing can give women a measure of relief from hot flash symptoms were either very small, conducted under unrealistic laboratory conditions or poorly designed, according to Dr, Carpenter and her colleagues.
Women assigned to do slow breathing
They set out to test slow breathing in a randomised controlled trial by assigning 88 women to use the slow breathing approach when they experienced a hot flash, 86 women to do the opposite - take quick, shallow breaths - and another 44 to behave as they would normally.
At eight weeks into the experiment, and then at 16 weeks in, at least some of the women in all three groups experienced fewer hot flashes per day, but there were no differences between the groups in the size of that change.
The severity of hot flashes and how much they bothered the women also decreased over time, but to roughly the same degree in each of the three groups. For other measures of well being, the results were mixed, and none of them appeared large enough to make a difference to women's lives, Dr Carpenter said.
For instance, negative mood worsened slightly, by less than one point on a 50-point scale, among women who did the slow breathing, while it improved slightly, by close to two points, for women who did the shallow breathing.
How hot flashes bothered women
Dr Carpenter said these differences were statistically significant, but in the real world, women would probably not notice such small changes. Dr Myra Hunter, a professor at King's College London who has studied paced respiration, said she found it to be helpful in reducing how much hot flashes bothered women.
Dr Hunter said disparities between her own findings and Dr Carpenter's could be because the women who used the breathing technique in her experiment also employed other cognitive and behavioural changes. "It is possible that adding cognitive strategies strengthened the effect. Further research is needed to unpack these specific elements of these interventions," Dr Hunter wrote in an email to Reuters Health.
Dr Margery Gass, the executive director of the North American Menopause Society, said the new study's results support other evidence that the benefits of alternative therapies for hot flashes, if any, are modest at best. Nonetheless, she said women can give slow breathing a try, because it doesn't have any side effects and it might help some women.
"Paced respiration, slow deep breathing, are thought to have beneficial effects to the body anyway," Dr Gass told Reuters Health. "And if some women have benefits, that's great and if some women don't, they can move on to some other therapy."
(Reuters Health, Kerry Grens, September 2012)
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