Previous studies have shown that people with red hair perceive pain differently than others.
They may be more sensitive to certain types of pain and can require higher doses of some pain-killing medications.
However, studies suggest that their general pain tolerance may be higher.
People with red hair also respond more effectively to opioid pain medications, requiring lower doses.
People with red hair have a variant of the melanocortin-1 receptor (MC1R) gene.
This gene controls the production of melanin, the pigment that gives skin, hair, and eyes their color.
The cells that make melanin produce two forms—eumelanin and pheomelanin. People with red hair produce mostly pheomelanin, which is also linked to freckles and fair skin that tans poorly.
While red hair has been linked to differences in pain processing, the underlying reasons weren’t well understood.
In a new study from Massachusetts General Hospital, researchers examined the connection between MC1R gene and pain perception.
They conducted their experiments using a strain of red-haired mice that carry the MC1R variant also found in people with red hair.
The mutation suppresses the function of the melanocortin 1 receptor. These mice show higher tolerance to pain.
They found that the melanocytes in red-haired mice secreted lower levels of a protein called proopiomelanocortin (POMC).
POMC is cut into different hormones, including one that enhances pain perception (melanocyte stimulating hormone) and another that blocks pain (beta-endorphin).
These hormones affect the balance between opioid receptors that inhibit pain (OPRM1) and melanocortin 4 receptors (MC4R) that increase pain sensitivity.
The presence of hormones that affect both these receptors would seem to maintain a balance. But the team found that the MCR1 red-hair variant altered the balance in favor of opioid receptors.
The reason for this imbalance is that separate opioid receptor hormones are plentiful and were essentially unchanged, whereas separate MC4R hormones are not known to exist, thus tipping the balance in favor of anti-pain opioid signals.
The end result was more opioid signals and a higher pain threshold.
Uncovering the mechanisms that affect pain perception in people with red hair may help medical personnel when caring for patients whose pain sensitivities may vary.
If you care about pain management, please read studies about what you need to know about headache pain, and native American plant med that could treat pain and diarrhea.
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The study was conducted by David E. Fisher et al., and published in Science Advances.
