Some studies indicate that redheads are more prone to illness because they prefer to keep out of the sun and so lack vitamin D, or because their ability to absorb the vitamin is less efficient.
It has long been known that redheads are at higher risk of sunburn and skin cancer. This is to be expected because red hair is associated with fair skin, which is more vulnerable to UV radiation [1].
We found that redheads were significantly more sensitive to cold pain perception, cold pain tolerance, and heat pain tolerance. Heat pain perception threshold was also lower, but not significantly so, in redheads.
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.
Lifespan: up to 20 years in captivity, 5-10 years in the wild.
Thanks to higher concentrations of red hair and pale skin in cloudy European environments, redheads gained a greater ability to create their own vitamin D. When they go outside, he or she produces more vitamin D in a shorter amount of time than people with other hair colours.
The results showed the average IQ of blonde-haired women was 103.2, 102.7 for brown hair, 101.2 for red hair and 100.5 for black hair. However, the differences were so small as to be unlikely to represent a real difference.
Redheads Look Older Than They Are
Some evidence suggests redheaded adults often appear older than their actual age. For example, one study published in 2016 in Current Biology found that adults who carry two copies of the MC1R gene variant are more likely to look two years older than other people their age.
Here's what studies have revealed about redheads and pain: They need about 20 percent more anesthesia to be sedated. They also need more local topical anesthetics, such as lidocaine or Novocain, which is why many redheads have a fear of dentists, according to the American Dentistry Association.
Most (natural) redheads will have brown eyes, followed by hazel or green shades.
The same mutation that makes their hair red is also what causes them to be more sensitive to temperature changes — even slight ones. They feel hot and cold temperature changes faster and with greater intensity than those with other hair colors.
Red hair is caused by a mutation of the melanocortin-1 receptor (MC1R), a type of gene responsible for producing pigment for skin and hair. An MC1R mutation may be involved in pain as well. It might also affect a person's response to anesthesia, which is given before procedures to prevent pain.
The summer heat can be red hot, particularly for gingers, who are much more sensitive to heat and at higher risk of skin cancer.
The DNA for blonde hair and red hair are about equally strong. People who have DNA for both often have strawberry blonde hair.
So, the answer to our question 'are redheads going extinct? ' is no. Redheads are less common and blue-eyed-left-handed-redheads are particularly rare, but they're not endangered and they won't die out due to that MC1R recessive gene.
Red hair is the result of a genetic variant that causes the body's skin cells and hair cells to produce more of one particular type of melanin and less of another. Most redheads have a gene mutation in the melanocortin 1 receptor (MC1R).
Redheads probably won't go grey. That's because the pigment just fades over time. So they will probably go blonde and even white, but not grey.
In fact, about a decade ago, British researchers reviewed all the existing medical literature on the subject and found no evidence to substantiate increased bleeding in red-heads.
A gene called MC1R plays a role in whether someone will have red hair. People who have certain variants in this gene are more likely to have red hair because they have higher levels of pheomelanin.
A new survey reported by the Daily Mail says ladies should start worrying in their 30s: specifically, ages 30, 32, and 35 (for redheads, brunettes, and blonds, respectively).
Subjects who carry the MC1R red-hair variant have increased sensitivity to opioid analgesics, implying redheads may need lower doses of opioid pain medications.
Simply put, achromotrichia is the absence of pigment in the hair. But while non-redheads gradually go grey and then perhaps to fully white hair, redheads actually retain their ginger colour for a lot longer, skipping out the greying stage.
Blonde women were slightly more likely to be in the highest IQ category than those with other hair colors, and slightly less likely to be in the lowest IQ category.
The study of 10,878 people found blonde-haired white women had an average IQ of 103.2, compared to 102.7 for those with brown hair, 101.2 for those with red hair and 100.5 for those with black hair.
Ireland has the highest number of red-haired people per capita in the world with the percentage of those with red hair at around 10%. Great Britain also has a high percentage of people with red hair.