To Live a Long Life, Keep Shaving
To find your approximate date of death, measure your telomeres. These are the pieces of DNA that protect the ends of our chromosomes and control how fast our cells age, and scientists think shortened telomeres cause early death. Some cloned mammals, such as Dolly the sheep, have shorter telomeres than other animals of the same age, leading scientists to think they'll have shorter lives. This is one reason why it's not yet safe to produce human clones. And men: keep shavingscientists don't know why, but shaving less than once a day increases your risk of stroke by 70%.
Geneticist Richard Cawthon believes that people age 60 or over who have shorter telomeres are eight times more likely to die from an infectious disease and three times more likely to have a fatal heart attack. The length of your telomeres at birth is genetic, and varies from person to person. But each time cells replicate, which they're constantly doing, the new cells have slightly shorter telomeres. In healthy people, telomeres don't shrink significantly until old age, but they eventually get so short that the DNA strands stop replicating or start fusing together, encouraging tumors to grow. White blood cells rely on their ability to replicate quickly in order to attack infections, which may be why older people with shorter telomeres are more likely to die from an infectious disease.
But Titia De Lange thinks that telomeres shrinking with old age can be a good thing, since it slows down cell replication and helps prevent older cells from turning cancerous.
Talk about a close shave: researchers have found that shaving less than once a day increases a man's risk of having a stroke by around 70%. The link between not needing to shave often and stroke risk comes from a 20-year study that started in the 1970s. When the study began, it was fashionable to be clean-shaven, and no one had heard of designer stubble. Men with beards weren't included in the study.
Researchers think the stroke protection comes because men who need to shave daily have more testosterone. However, the study results are puzzling because baldness, which is also linked to high testosterone, is associated with a higher risk of heart disease.
The men who didn't shave daily were more likely to smoke and do manual work, and less likely to be married. These are all risk factors for stroke, although the researchers say they accounted for them in their study and still found men who shaved less often had a 70% increased stroke risk and a 30% increased risk of dying from any cause.
If we have short telomeres and light beards, we'll die one way, if we have long telomeres, another.