People with red hair are attributed many sweepingly generalized characteristics due to their hair color. They’re said to have a fiery temperament, to be rash and quick to action. Obviously, these aren’t scientifically true; there are just as many easy-going redheads as there are fiery ones. It’s also been said that people with red hair have a different experience of pain than other people, that anesthesia therefore works on them differently than it does on other people. Is this true, or is it as much of a fabrication as the old line about intemperance?
That one may actually be true. Several studies have been conducted over the years investigating the way redheads experience pain, and the amount of painkillers they require. As with most such sweeping statements, the belief that redheads interpret and process pain differently is difficult to either prove or disprove, and may be true in certain ways and untrue in others. That being said, evidence is there to suggest that there is something to this tale.
Natural redheads have a mutated gene called MC1R in the cells producing the pigment in their skin and hair. According to genetic researchers, the same mutation which affects the pigment also triggers the release of a hormone called Pheomelanin, which causes the rubicund, red color to skin. It is more present in women than men. These hormones affect melanocytes, which are cells that produce melanin, the pigment that colors skin. Interestingly, Pheomelanin also affects pain receptors in the brain, which control the body’s processing of pain.
According to at least two studies, people with red hair process pain differently than people who have other hair colors. One found that redheads have a lower tolerance for thermal pain; that is, pain associated with temperatures. This is linked to a natural deficiency in levels of vitamin K. The other study found that redheads have a higher tolerance for electrically induced pain that people of other hair colors.
Other studies have been conducted to determine the amount of anesthesia required by redheads, although the information from these studies is inconclusive. Some researchers believe that redheads actually require greater amounts of anesthesia to block out pain, while another study found that women with red hair require less pentazocine to block pain than do women with other hair colors.