Nipple stimulation promotes the production of a useful female hormone which encourages cells to expel cancer-causing chemicals from breast ducts, it was said yesterday by Professor Tim Murrell, of the Department of Community Medicine, at the University of Adelaide.
Professor Murrell said they recommend two to three minutes of nipple stimulation twice a week. 'We ask our patients . . . to involve their partners. Women who are alone can do this for themselves by squeezing their nipples or by using a rough flannel.'
His ideas were presented yesterday to the Lancet conference on breast cancer in Bruges, Belgium. He emphasised that his approach was new, controversial and sensitive, since it is not usual in breast cancer consultations to ask women to give such detailed accounts of their sexual behaviour. The only breast care history questions doctors ask is whether a women has breast-fed her children, he said.
Breast cancer risk is known to be lower in women who have breast- fed their babies, and his theory is based on the properties of the hormone oxytocin produced during lactation. Oxytocin is also produced at orgasm. One of the functions of the hormone is to cause breast cells to contract to expel milk or other breast fluid from them.
Professor Murrell said that 5,000 women at his general practice university clinic had enrolled in the nipple stimulation programme, started three years ago. 'We would expect to be seeing two or three breast cancers a year based on a population of this size. All I can say is that we have not seen one since we began,' he said.
In his paper he says that sexual activity in women who have no children protects them as oxytocin levels are shown to rise in orgasm. 'Oxytocin systems in the brain are intricately linked to oestrogen and progesterone levels and it is possible that these hormones may have an effect on the secretion of oxytocin in the breast.'
Professor Murrell said the idea had started after a woman patient, who suffered from lumpy and painful breasts, had remarried. 'When I next saw her, I asked about her breast problem. She said the difficulties had disappeared, because her second husband was much better at loving her breasts.'
He added that in the early 18th century a Lancashire physician, Edward Baynard, complained that women who wanted to be fashionable, with squashed breasts and flattened nipples, were at risk from cancers and hard tumours.
He said: 'Nipple care is an accepted practice during lactation and should be extended into the post-reproductive, pre-menopausal and post-menopausal years. The regular production of oxytocin from nipple stimulation is a key factor in this notion of breast care prevention.'