In a phone conversation, Sister-in-Law Teresa noted she had found online an article suggesting redheads are more sensitive to pain. I quote in part:
People with red hair are more sensitive to pain and consequently need more anesthetic during operations than other patients, according to new research.
"Red hair is the first visible human trait, or phenotype, that is linked to anesthetic requirement," says anesthesiologist Edwin Liem, who conducted the research at the Outcomes Research Institute of the University of Louisville, US.
In people with red hair, the cells that produce skin and hair pigment have a dysfunctional melanocortin 1 receptor. Liem says this dysfunction triggers the release of more of the hormone that stimulates these cells, but this hormone also stimulates a brain receptor related to pain sensitivity.
I didn’t know red hair was related to a "dysfunctional melanocortin 1 receptor." I don’t know what that means, but it doesn’t sound good. Red heads are known also to be susceptible to skin cancer. Although what skin has to do with hair or why the two should be related, I don’t. On the up side, red hair appears evolutionarily adaptive in that this dysfunctional receptor is related to a redheads’ ability to synthesize vitamin D with relatively low sunlight exposures. So as one site puts it redheads tend to appear in dark parts of the world, or the fringes of Western Europe.
I bring this up only because once upon a time I was a redhead. Now you wouldn’t know it but back in ’73 I looked like this:
I have been proud of few things in my life, but I was proud of that damn hair. And now it’s all gone, though I still have that dysfunctional receptor.