Scientists have found the first proof that yoga can ease the pain of pre-menstrual tension.
Tests on women with the pre-period syndrome have found the ancient Indian art form can relieve their psychological and physical symptoms. Furthermore, it appears yoga can actually lift levels of an antidepressant-like hormone, allopregnanolone, typically low in chronic sufferers.
But women's health specialists are sceptical about the findings and say most women with PMS need more than stretching and meditation to get relief.
Indian researcher Dr Ratna Sharma has told the World Congress of Neuroscience in Melbourne that she has the first scientific evidence that yoga helps PMS.
"It is widely understood in India that yoga works (for PMS) but we've never shown it,'' said Dr Sharma, a physiologist at the All India Institute of Medical Sciences in New Delhi.
"The fact that it appears to influence symptoms and also change levels of an important hormone is very significant indeed.''
Researchers enlisted more than 40 women to practise yoga intensively, at least five times a week, for a month.
Half suffered the symptoms of PMS, typically psychological stress, depression, body aches and bloating in the week before a monthly period. Extensive questionnaires completed before and after the course showed yoga significantly reduced PMS symptoms in 64 per cent of sufferers.
"The women with the worst psychological symptoms benefited most,'' Dr Sharma said.
Researchers also tested participants' hormone levels before the yoga course and found sufferers had significantly lower levels of allopregnanolone, an important biochemical known for its antidepressant qualities.
But after the trial, levels had risen, particularly in women whose depression had been alleviated.
Dr Sharma said the yogic activity somehow stimulated a hormonal change which in turn relieved symptoms, but how it did this was not known.
Dr Sue Reddish, medical director of the Jean Hailes Medical Centre for Women in Melbourne, said relaxation and exercise were known to help depression, which is closely linked to PMS.
"If yoga is enough to help a particular person that's good, but I doubt it's enough for the majority of women with severe PMS,'' Dr Reddish said.
"And I really can't see how yoga would altar your hormone levels.''
She recommended classical treatments for PMS which include vitamin B6 supplements, evening primrose oil, or management with certain contraceptive pills or low dose antidepressants. （實習編輯：顧萍）