http://www.guardian.co.uk/science/2008/aug/13/medicalresearch.medicaladvicefortravellers/print
"Taking the contraceptive pill can lead a woman to choose the "wrong" partner, the findings of a study published today suggest. The pill is thought to disrupt an instinctive mechanism that brings people with complementary genes and immune systems together. By passing on a wide-ranging set of immune system genes, they increase their chances of having a healthy child that is not vulnerable to infection. Couples with different genes are also less likely to experience fertility problems or miscarriages. Experts believe women are naturally attracted to men with immune system genes that differ their own because of their smell. The major histocompatability complex (MHC) cluster of genes, which helps build proteins involved in the body's immune response, also influences smell signals called pheromones. Although pheromones may be almost unnoticeable at a conscious level, they can exert a potent effect. A man's pheromonal odour is partly determined by his MHC. From a woman's point of view, a man with an alluring smell is also likely to have suitable immune system genes. The new research provides evidence that the contraceptive pill can upset this process. Researchers asked 100 women to sniff six male body odour samples from 97 volunteers and say which they preferred, with tests carried out both before and after the women had started taking the pill. "The results showed that the preferences of women who began using the contraceptive pill shifted towards men with genetically similar odours," the University of Liverpool's Dr Craig Roberts, who led the study, said. "Not only could MHC similarity in couples lead to fertility problems, it could also ultimately lead to the breakdown of relationships when women stop using the contraceptive pill, as odour perception plays a significant role in maintaining attraction to partners." Being on the pill simulates a state of pregnancy, which may reverse a woman's reaction to male odours. Finding particular men sexually attractive is not so important once a woman is expecting a child." Romance Maru -- William T Goodall Mail : [EMAIL PROTECTED] Web : http://www.wtgab.demon.co.uk Blog : http://radio.weblogs.com/0111221/ "There's no chance that the iPhone is going to get any significant market share. No chance" - Steve Ballmer _______________________________________________ http://www.mccmedia.com/mailman/listinfo/brin-l
