Most red hair is caused by the MC1R gene and is non-pathological. However, in rare cases red hair can be associated with disease or genetic disorders: In cases of severe malnutrition, normally dark human hair may turn red or blonde.
This is to be expected because red hair is associated with fair skin, which is more vulnerable to UV radiation [1]. Less expectedly, red hair is also associated with pain sensitivity, endometriosis, Parkinson's disease, decreased platelet function and, perhaps, defects in the immune system [2–11].
Red hair originates from mutations in a gene involved in skin and hair pigmentation, called melanocortin 1 receptor (MC1R) on chromosome 16.
Redheads feel hot and cold temperatures more severely than anyone else. In 2005, the University of Louisville discovered this hidden gift and hypothesised that the redhead gene, MC1R may cause the human temperature-detecting gene to become over-activated, making redheads more sensitive to thermal extremes.
Humans and mice with red hair have a different tolerance for pain because their skin's pigment-producing cells lack the function of a certain receptor. Lack of this receptor function causes changes that tip the balance between pain sensitivity and pain tolerance.
Lifespan: up to 20 years in captivity, 5-10 years in the wild. Special Adaptations: Males have an elaborate courtship dance where they throw back their heads, almost touching their tail!
Having red hair isn't the only thing that makes some redheads unique. They are also more likely to be left handed. Both characteristics come from recessive genes, which like to come in pairs. Redheads probably won't go grey.
Because MC1R affects the body systemically, the mutation also dictates other differences in the ginger-haired. While it makes redheads more susceptible to sunburn, that very sensitivity to ultraviolet rays also allows their bodies to produce more vitamin D, which is essential to bone development and good health.
Having red hair and blue eyes is the rarest hair/eye color combination possible. The odds of a person having both of those recessive traits is around 0.17%.
The percentage of redheads in Ireland hovers around the 10% mark. Scotland weighs in at around 6%, followed by England at around 4%. Scottish people may disagree, but we say Ireland is the undisputed world capital of redheads.
Redheads might have less damage/signs of aging
This means that there is a reduced risk of sun damage and early signs of aging in the skin of redheads. This means our skin stays youthful for longer, helping us appear younger.
The skin of a redhead is thinner compared to others and is derived from the ectoderm. Teeth enamel is also derived from the ectoderm and thus is thinner than usual. Since the enamel coating is thin, the inner layer of tooth-dentin is more visible and offers a yellowish appearance.
As mentioned above, the amount of melanin you produce is influenced by your genes, and as a result, hair color can be considered a genetically determined characteristic or trait. Red hair runs in families, but non-redhead parents can also have a red haired child.
First up, studies have found that people with ginger hair are better in bed. This is because of a specific gene connected to redheads – the MC1R gene. This gene makes the individual more sensitive to touch than people with other hair colours.
Research has 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.
Now you know what is the most common hair colour in the world, but what about the rarest? The rarest natural hair colour is red, which makes up only one to two percent of the global population. You commonly see these hair colours in western and northern areas of Europe, especially Scotland and Ireland.
The rarest hair and eye color combination is red hair with blue eyes, occurring in less than 1% of the global population. This statistic is a powerful reminder of the uniqueness of the red hair and blue eyes combination.
What is the rarest eye color? Green is the rarest eye color in the world, with only 2% of the world's population (and fewer than one out of ten Americans) sporting green peepers, according to the American Academy of Ophthalmology (AAO).
In the past five years, researchers have found that the genetic mutation responsible for redhead's ruby tresses and snow-white skin also makes them more sensitive to hot and cold -- and it could also make them a whole lot harder to numb up.
As a group, redheads seem to be more likely to develop certain health conditions and have certain health risks. These include: Increased skin cancer risk. Altered sensitivity to pain.
Some people with red hair also experience pain differently, or they can look older than they are. At the same time, redheads are better at manufacturing vitamin D and have a lower prostate cancer risk. The reason for those differences is rooted in DNA.
One of the many facts about redheads is that their hair will never turn grey. The pigment in their hair that causes it to be red will just fade over time, causing their hair to turn blonde or white, but never grey.
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.
Put simply, 'achromotrichia' is defined as the absence or loss of pigmentation in the hair. Thanks to genetics, gingers tend to retain their red hair colour for a lot longer, skipping out the greying stage that most other people experience.