A large team led by researchers at Boston hospitals recently reported a surprising result: a common variation in a gene was associated with being an early bird, and with the time of day people died.
Given how many things affect when we wake up — not to mention all the experiences accumulated over a lifetime that contribute to how and when we die — it seems a little crazy that a single gene could be meaningfully linked to those complicated traits.
But over the years, it has become increasingly clear that our bodies run on their own clocks and that health is inextricably linked to those rhythms. Shift workers forced to adopt a schedule wildly out of rhythm with a typical day raise their risk of obesity and diabetes. Heart attacks have a propensity to strike in the morning and asthma attacks at night. A growing body of evidence suggests giving cancer drugs at specific times of day can make a therapy’s side effects less harsh.
The scientists who published the new findings in the Annals of Neurology said the research needs to be repeated in a larger group of people to see whether it holds up. They acknowledged that a complex trait such as being a night owl or dying at dusk rather than midday would probably have many contributions, not just one gene. But, given the importance of our body’s natural rhythms, they and others argue, it is important to try and unravel the biology of the clock.
“What you’d like to do is you’d like to see if there’s some predictive value here,” said Dr. Clifford Saper, chief of neurology at Beth Israel Deaconess Medical Center, and a coauthor. “Could you predict who would be able to adjust to a job that requires that you start at 6 a.m.? . . . Would you be able to pick your job based on knowing your” genetic predisposition.
Researchers not involved in the study said it was a fascinating result, but just a first step in teasing out how the human body clock works and what effect upsetting the clock can have.