How hair colour can determine your pain threshold

London, Mar 26 (ANI): In a new study, researchers have tried to investigate whether pale-skinned and red-haired people react differently to pain.

Researchers at Southampton University Hospital recruited redheaded volunteers aged over 30, anaesthetised them and gave them small electric shocks on the thigh.

Their reactions were then compared with a control group of men and women with brown or black hair.

The trial, which is due to end in September, will no doubt be of interest to the redheaded 3 percent of the British population, such as 'Doctor Who' actress Karen Gillan.

Red hair is the result of a variant of a gene that plays a key role in human hair and skin colour.

This same gene is involved in the production of endorphins, the body's natural painkiller, and could influence pain thresholds, according to other research.

A U.S. study published in 2002 found that women with red hair needed 19 percent more painkiller to stop them flinching during unpleasant stimulation than women with dark hair.

The same researchers also found in 2009 that redheads were more anxious about dental treatment and more than twice as likely to avoid a visit.

"Redheads experience more pain from a given stimulus and therefore require more anaesthesia to alleviate that pain. The art and science of anaesthesiology is determining just the right amount of anaesthesia to achieve unconsciousness, pain tolerance and suppression of memory without causing adverse consequences, such as cardiac or pulmonary complications," the Daily Mail quoted Edwin Liem, the study leader from Louisville University, said.

"Red hair is apparently an important element in this decision," Liem said. (ANI)