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Surprising Factoids about Redheads including their relationship with Neanderthals

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    Surprising Factoids about Redheads including their relationship with Neanderthals

    I don't know how "scientific" the following data is but the fact that they have a higher pain threshold is interesting and may be related to the fact that they are more sensitive to endogenous opioids.

    Scientific Facts About Redheads

    • Redheads Have Higher Pain Threshold
    • Men and women with naturally red hair can withstand 25 percent more electric shock than non-redheads. And painkillers used in childbirth work three times better on red-haired women than on others
    • Redheads have the smallest number of hair strands - On average there are over 100,000 strands of hair on a young adult. Blondes average about 140,000 strands, brunettes average 108,000 and redheads average 90,000
    • Red hair is usually thicker and coarser than blond hair so it appears fuller.
    • Red pigment is an inadequate filter of sunlight and redheads skin is more susceptible to sunburn, skin cancer and wrinkling with age
    • Percentages of redheads in different countries range from single digits to a fraction of 1 per cent—a recent estimate for France is 0.03 per cent of people. (A 1977 estimate for North America is 4 per cent.)
    Here are some even more surprising information.
    It appears that Neanderthals were redheads!

    Ancient DNA retrieved from the bones of two Neanderthals suggests that at least some of them had red hair and pale skin, scientists report this week in the journal Science. The international team says that Neanderthals’ pigmentation may even have been as varied as that of modern humans, and that at least 1 percent of Neanderthals were likely redheads.

    The scientists — led by Holger Römpler of Harvard University and the University of Leipzig, Carles Lalueza-Fox of the University of Barcelona, and Michael Hofreiter of the Max Planck Institute for Evolutionary Anthropology in Leipzig — extracted, amplified, and sequenced a pigmentation gene called MC1R from the bones of a 43,000-year-old Neanderthal from El Sidrón, Spain, and a 50,000-year-old individual from Monti Lessini, Italy.

    “Together with other genes, this MC1R gene dictates hair and skin color in humans and other mammals,” says Römpler, a postdoctoral researcher working with Hopi E. Hoekstra in Harvard’s Department of Organismic and Evolutionary Biology. “The two Neanderthal individuals we studied showed a point mutation not seen in modern humans. When we induced such a mutation in human cells, we found that it impaired MC1R activity, a condition that leads to red hair and pale skin in modern humans.”

    To ensure that the MC1R point mutation was not due to contamination from modern humans, the scientists checked some 3,700 people, including those previously sequenced for the gene as well as everyone involved in the excavation and genetic analysis of the two Neanderthals. None showed the mutation, suggesting that Neanderthals and Homo sapiens followed different evolutionary paths to the same redheaded appearance.

    With Neanderthals’ surviving bones providing few clues, scientists have long sought to flesh out the appearance of this hominid species found across Eurasia some 28,000 to 400,000 years ago. While anthropologists had predicted that Neanderthals might have had pale skin or red hair, the new work by Römpler and colleagues offers the first strong evidence to support this hunch.

    Found in cell membranes, MC1R is a receptor that acts as a switch between production of the red-and-yellow pigment pheomelanin and the black-and-brown pigment eumelanin. Modern humans with mutations that cause complete or partial loss of MC1R function tend to be pale and red haired, although many other pigmentation genes can also result in this phenotype.
    Now, what about Eric the Redhead... the Thirteenth Warrior.

    Last edited by Wise Young; 17 Nov 2008, 9:34 AM.

    The definitely didn't study my boyfriend in high school with the red hair. The biggest wuss I've ever known. My aunt or nephew either. Whiney.
    If you can't handle me at my worst, then you sure as hell don't deserve me at my best.

    Sometimes it is easier to widen doors than it is to open minds.


      Here are more
      Redhead facts & myths
      Good Lord I should go into hiding!

      1. Red hair is seen on the heads of only four percent of people. Most of these exist in the U.K., the Republic of Ireland, and Australia.
      2. There is a belief that redheads are prone to industrial deafness. This actually could be true as the melanocytes are found in the middle ear.
      3. A 2002 study found that redhead are harder to sedate than any other people requiring twenty percent more anesthesia. Inadequate doses cause people to wake up during surgery and have increased recall of procedures.
      4. In the late 16th century, the fat of a redheaded man was an essential ingredient for poison. The Egyptians regarded the color as so unlucky that they had a ceremony in which they burned red-headed maidens alive to wipe out the tint.
      5. An Irish judge in 2001 fined a man for disorderly conduct stating "I am a firm believer that hair coloring has an effect on temper and your coloring suggests you have a temper."
      6. Redheads have always been thought untrustworthy. Judas is most always depicted as a redhead displaying the prejudice against red hair.
      7. Adolph Hitler reportedly banned the marriages of two redheads as he feared their children would be "deviant offspring".
      8. Red haired children have been historically branded as offspring of "unclean" sex. This has earned them taunts such as "red-knob" or "tampon tops."
      9. Bees are thought to sting redheads more than others.
      10. In Denmark it is an honor to have a redheaded child.
      11. In Corsica, if you pass a redhead in the street you are to spit and turn around.
      12. In Poland, if you pass three red-heads you'll win the state lottery.
      13. In Greek Mythology, redheads turn into Vampires when they die.
      14. During the Spanish Inquisition flame colored hair was evidence that its owner had stolen the fire of hell and had to be burned as a witch.
      15. Russian tradition declares that red hair is both a sign that a person holds a fiery temper and craziness.
      16. A Russian Proverb warns "There was never a saint with red hair."
      17. Aristotle was known to believe that redheads were emotionally unhousebroken.
      18. A French Proverb states that "redheaded women are either violent or false, and usually are both."
      I wonder how many of these were made up by redheads. Of these, only the first three seemed to be reasonable. The rest appear to be fabricated hyperbole.

      The "belief" and redheadedness is associated with "industrial deafness" (whatever that is) is not well supported by data. There was one study that suggested that described ataxia-deafness-retardation in three sisters, all of whom happen to have red hair. Not very impressive statistical sample.
      Koletzko S, Koletzko B, Lamprecht A and Lenard HG (1987). Ataxia-deafness-retardation syndrome in three sisters. Neuropediatrics. 18: 18-21. Three sisters aged 16, 12 and 8 years from a consanguineous family presented with a progressive spinocerebellar ataxia combined with moderate mental retardation, progressive sensorineural hearing loss and signs of both upper and lower motor neuron disease. The patients represent the only known cases of the ataxia-deafness-retardation syndrome (McKusick #20885) except for the three brothers in the original description by Berman et al (1973). In the family described here transmission of the disease appears to be linked with occurrence of red hair colour.
      However, it does appear that red-headed volunteers have a higher resistance to the sedative midazolam. The abstract of the paper on sedatives is as follow:
      Chua MV, Tsueda K and Doufas AG (2004). Midazolam causes less sedation in volunteers with red hair. Can J Anaesth. 51: 25-30. Department of Anesthesiology and the Outcomes Research Institute, University of Louisville School of Medicine, Louisville, Kentucky 40292, USA. PURPOSE: We studied sedation, cognition, and mood during midazolam infusion in volunteers with red and non-red (blond or brown) hair, to test the hypothesis that patients with red hair may require more drugs to attain desired levels of sedation. METHODS: Twenty red and 19 non-red hair subjects were studied in a randomized, placebo-controlled cross-over design. Subjects were studied during placebo and midazolam at 30 ng.mL(-1) target effect site concentration. Sedation was assessed using the observer's assessment of alertness/sedation (OAA/S) scale, the drowsiness visual analogue scale (VAS), and the bispectral index; cognition was assessed using the Repeatable Battery for Assessment of Neuropsychological Status; and mood was assessed using the bipolar form of the Profile of Mood States (POMS). RESULTS: Red hair volunteers showed significantly higher OAA/S (P < 0.01) and lower drowsiness VAS (P < 0.05) scores compared to non-red hair subjects during midazolam infusion. Visuospatial score was significantly higher in subjects with red compared to non-red hair during placebo and midazolam trials. Delayed memory score was significantly higher during midazolam infusion in subjects with red compared to non-red hair. There were no group differences in POMS during either trials. CONCLUSION: Midazolam appears to cause significantly less sedation and cognitive impairment in red haired subjects.
      It is also true that red-hair is associated with a slightly higher risk of having several variants of the melanocortin receptor 1 gene which predisposes to melanoma. These are so called low-risk genes.
      • Kanetsky PA, Rebbeck TR, Hummer AJ, Panossian S, Armstrong BK, Kricker A, Marrett LD, Millikan RC, Gruber SB, Culver HA, Zanetti R, Gallagher RP, Dwyer T, Busam K, From L, Mujumdar U, Wilcox H, Begg CB and Berwick M (2006). Population-based study of natural variation in the melanocortin-1 receptor gene and melanoma. Cancer Res. 66: 9330-7. Department of Biostatistics and Epidemiology and Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6021, USA. Natural variation in the coding region of the melanocortin-1 receptor (MC1R) gene is associated with constitutive pigmentation phenotypes and development of melanoma and nonmelanoma skin cancers. We investigated the effect of MC1R variants on melanoma using a large, international population-based study design with complete determination of all MC1R coding region variants. Direct sequencing was completed for 2,202 subjects with a single primary melanoma (controls) and 1,099 subjects with second or higher-order primary melanomas (cases) from Australia, the United States, Canada, and Italy. We observed 85 different MC1R variants, 10 of which occurred at a frequency >1%. Compared with controls, cases were more likely to carry two previously identified red hair ("R") variants [D84E, R151C, R160W, and D294H; odds ratio (OR), 1.6; 95% confidence interval (95% CI), 1.1-2.2]. This effect was similar among individuals carrying one R variant and one r variant (defined as any non-R MC1R variant; OR, 1.6; 95% CI, 1.3-2.2) and among those carrying only one R variant (OR, 1.5; 95% CI, 1.1-1.9). There was no statistically significant association among those carrying only one or two r variants. Effects were similar across geographic regions and categories of pigmentation characteristics or number of moles. Our results confirm that MC1R is a low-penetrance susceptibility locus for melanoma, show that pigmentation characteristics may not modify the relationship of MC1R variants and melanoma risk, and suggest that associations may be smaller than previously reported in part due to the study design.
      • Han J, Kraft P, Colditz GA, Wong J and Hunter DJ (2006). Melanocortin 1 receptor variants and skin cancer risk. Int J Cancer. 119: 1976-84. Channing Laboratory, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA. Melanocortin 1 receptor (MC1R) gene variants are associated with red hair and fair skin color. We assessed the associations of common MC1R genotypes with the risks of 3 types of skin cancer simultaneously in a nested case-control study within the Nurses' Health Study (219 melanoma, 286 squamous cell carcinoma (SCC), and 300 basal cell carcinoma (BCC) cases, and 873 controls). We found that the 151Cys, 160Trp and 294His variants were significantly associated with red hair, fair skin color and childhood tanning tendency. The MC1R variants, especially the 151Cys variant, were associated with increased risks of the 3 types of skin cancer, after controlling for hair color, skin color and other skin cancer risk factors. Carriers of the 151Cys variant had an OR of 1.65 (95% CI, 1.04-2.59) for melanoma, 1.67 (1.12-2.49) for SCC and 1.56 (1.03-2.34) for BCC. Women with medium or olive skin color carrying 1 nonred hair color allele and 1 red hair color allele had the highest risk of melanoma. A similar interaction pattern was observed for red hair and carrying at least 1 red hair color allele on melanoma risk. We also observed that the 151Cys variant contributed additional melanoma risk among red-haired women. The information on MC1R status modestly improved the risk prediction; the increase was significant for melanoma and BCC (p, 0.004 and 0.05, respectively). These findings indicated that the effects of the MC1R variants on skin cancer risk were independent from self-reported phenotypic pigmentation.
      • Gandini S, Sera F, Cattaruzza MS, Pasquini P, Zanetti R, Masini C, Boyle P and Melchi CF (2005). Meta-analysis of risk factors for cutaneous melanoma: III. Family history, actinic damage and phenotypic factors. Eur J Cancer. 41: 2040-59. Department of Epidemiology and Biostatistics, European Institute of Oncology IRCCS, Via Ripamonti 435, 20141 Milan, Italy. A systematic meta-analysis of observational studies of melanoma and family history, actinic damage and phenotypic factors was conducted as part of a comprehensive meta-analysis of all major risk factors for melanoma. Following a systematic literature search, relative risks were extracted from 60 studies published before September 2002. Fixed and random effects models were used to obtain pooled estimates for family history (RR = 1.74, 1.41-2.14), skin type (I vs. IV: RR = 2.09, 1.67-2.58), high density of freckles (RR = 2.10, 1.80-2.45), skin colour (Fair vs. Dark: RR = 2.06, 1.68-2.52), eye colour (Blue vs. Dark: RR = 1.47, 1.28-1.69) and hair colour (Red vs. Dark: RR = 3.64, 2.56-5.37), pre-malignant and skin cancer lesions (RR = 4.28, 2.80-6.55) and actinic damage indicators (RR = 2.02, 1.24-3.29). Sub-group analysis and meta-regression were carried out to explore sources of between-study variation and bias. Sensitivity analyses investigated reliability of results and publication bias. Latitude and adjustment for phenotype were two study characteristics that significantly influenced the estimates.
      And there does appear to be increased risk of endometriosis in women who are nturally red haired but had never been infertile
      1. Missmer SA, Spiegelman D, Hankinson SE, Malspeis S, Barbieri RL and Hunter DJ (2006). Natural hair color and the incidence of endometriosis. Fertil Steril. 85: 866-70. Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA. OBJECTIVE: To investigate a previously hypothesized relation between natural hair color and endometriosis. DESIGN: Prospective cohort study. SETTING: Nurses' Health Study II with 10 years of follow-up. PARTICIPANT(S): A total of 90,065 women, 25-42 years old, who had never been diagnosed with endometriosis, infertility, or cancer at baseline in 1989. MAIN OUTCOME MEASURE(S): Incidence of laparoscopically confirmed endometriosis according to natural hair color. RESULT(S): During 379,422 person-years of follow-up, 1,130 cases of laparoscopically confirmed endometriosis were reported among women with no past infertility. After adjusting for age, calendar time, parity, race, and body mass index at age 18, we observed no association overall. However, compared with women with any other hair color, we observed an increased rate of endometriosis among women with naturally red hair who had never been infertile (incidence rate = 1.3, 95% confidence interval [CI] = 1.0-1.7), but a decreased rate among women with naturally red hair among women who were infertile (incidence rate = 0.4, 95% CI = 0.2-1.2); P value, test for heterogeneity = .03. CONCLUSION(S): Overall, we did not observe a significant relation between red hair color and the rate of endometriosis, however this prospective cohort study suggests that the relation may differ by infertility status.
      However, red hair is not a statistically significant risk factor for uveal melanoma.
      1. Weis E, Shah CP, Lajous M, Shields JA and Shields CL (2006). The association between host susceptibility factors and uveal melanoma: a meta-analysis. Arch Ophthalmol. 124: 54-60. Department of Epidemiology, Harvard School of Public Health, Boston, MA, USA. OBJECTIVE: To conduct a meta-analysis, using observational studies, to examine the association between host susceptibility factors and uveal melanoma. METHODS: A review of 132 published reports on risk factors for uveal melanoma revealed 10 case-control studies that provided enough information to calculate odds ratios (ORs) and standard errors for host susceptibility factors. Data from these studies were extracted and categorized. Summary statistics were calculated for all risk factors reported by at least 4 independent studies. RESULTS: Summary statistics using meta-analysis are presented as ORs and their 95% confidence intervals (CIs). Statistically significant risk factors include light eye color (OR, 1.75 [95% CI, 1.31-2.34]), using 10 studies (1732 cases); fair skin color (OR, 1.80 [95% CI, 1.31-2.47]), using 5 studies (586 cases); and ability to tan (OR, 1.64 [95% CI, 1.29-2.09]), using 6 studies (1021 cases). Blond or red hair color, using 7 studies (1012 cases), was not a statistically significant independent risk factor (OR, 1.02 [95% CI, 0.82-1.26]). CONCLUSION: This meta-analysis yielded strong evidence associating the host susceptibility factors of iris color, skin color, and ability to tan with uveal melanoma.