Flame-haired women, like actress Nicole Kidman, are a lot better than blondes and brunettes at coping with pain.
A team of British scientists is investigating the gene responsible in the hope that it will lead to the development of new anaesthetics and pain killing drugs.
Professor Ian Jackson, from the Medical Research Council’s Human Genetics Unit, is working with “redhead” mice mimicking the same gene mutation.
The mice actually have yellow fur rather than red hair. But like their human counterparts, they seem to have an unusual ability to withstand pain.
Ladies in red
“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,” Professor Jackson said.
His team is collaborating with Edinburgh University scientists to find ways of testing pain sensitivity in different strains of mice. The researchers will then start applying their findings to humans.
The ultimate goal is to find new biochemical pathways that can be used to develop better ways of combating pain.
Gene gives higher pain threshold
Prof Jackson is building on work originally carried out by Professor Jeffrey Mogil, at McGill University in Canada.
Prof Mogil identified a mutant version of a gene called melanocortin-1 (Mc1r) that is linked to ginger hair and fair skin.
The gene variant also gives women a higher pain threshold, but does not appear to have the same effect on men.
Normally when humans and other mammals experience discomfort, the body reacts to dull it by releasing natural morphine-like opioid substances.
Prof Mogil copied this effect by giving women doses of an artificial painkiller and seeing how well it worked.
The painkilling effect was three times greater for redheaded women than for blondes and brunettes, or men.