Aw: Why surgeons dread redheads

Operating room docs, for example, have long reported that redheads appear to need more anesthetic than others. The new study suggests that that observation is an accurate one — mostly. Those with the MC1R mutation are more sensitive to opiate pain killers — which means they’d actually need less — but less sensitive to other types, most notably lidocaine injections. One study which used heat-related pain as its litmus of overall sensitivity showed that redheads indeed felt things more acutely and unpleasantly, probably because the MC1R mutation releases a hormone that stimulates a brain receptor associated with pain regulation. (More on Time.com: Study: Researchers Identify Hundreds of Gene Variants That Contribute to Height)

Redheads are also said — anecdotally at least — to be more susceptible to hernias. The study did not establish that conclusively, but it did find a tangential link between chromosome 16 and a condition called brittle cornea syndrome, the sufferers of which have a slightly elevated hernia risk.