Redheaded women conquer the pain barrier

For reasons that have yet to be understood, women with red hair appear to be more resistant to pain compared to women with other colours of hair, and men, a scientist said yesterday.

The preliminary findings will be investigated in a study to be launched in Britain by the Medical Research Council's Human Genetics Unit in Edinburgh which has recruited a panel of redheads to take part in the research.

One of the aims is to see if there is a natural mechanism at work in redheads that can be adapted to help in developing new pain-killers and anaesthetics, said Professor Ian Jackson.

"People would be interested in the possibility of developing new anaesthetics or co-anaesthetics. Treatment for chronic pain is difficult, for example pain from cancer. It's difficult to regulate and people are looking for drugs in that area," Professor Jackson said.

Studies on "redhead" mice ­ which have blonde fur but carry a similar gene to the one that causes red hair in humans ­ is helping the scientists target the pain-reducing mechanism.

Professor Jackson said that red-haired mice exhibit a similar ability of human female redheads to withstand higher pain thresholds compared to other mice.

"The nature of it is still being worked out, but it does appear that redheads have a significantly decreased pain threshold and require less anaesthetic to block out certain pains," he said.

Work on red hair and pain was originally carried out by Professor Jeffrey Mogil, at McGill University in Montreal, Canada, who identified a mutant version of a gene called melanocortin-1 (Mc1r), which is linked to ginger hair and fair skin, gives women a higher pain threshold, but does not appear to have the same effect on men. It is thought this is explained by subtle differences in the way male and female brains process pain.

In most people, the Mc1r gene produces a protein that reduces the ability of opioid drugs to block pain. But in redheaded women, who have a non-functional version of the gene, such painkillers are free to work unhindered.