Here’s another health threat to lose sleep over: Too much sleep can kill you. But too little sleep can kill you, too, according to a British study released yesterday.
The real eye-opening news? The traditional eight-hours-a-night model may be out the window.
“In terms of prevention, our findings indicate that consistently sleeping around seven hours per night is optimal for health,” said Dr. Francesco Cappuccio, professor of cardiovascular medicine at the University of Warwick at the annual conference of the British Sleep Society.
After poring over the sleep habits and health outcomes of more than 10,000 British workers during two five-year periods, Dr. Cappuccio and a research team from University College London found that chronic lack of sleep can more than double the risk of death from cardiovascular disease.
They also found that those who snooze more than eight hours a night can more than double the risk of death from a variety of causes — a finding the researchers deemed “curious.”
Their study will be published next month in Sleep, a medical journal.
A good night’s sleep has become a rare commodity in this day and age.
“Fewer hours sleep and greater levels of sleep disturbance have become widespread in industrialized societies,” Dr. Cappuccio said, adding that we sleep less to accommodate heavier work schedules and an increased taste for leisure.
Forty million Britons have trouble sleeping — British teens, in particular. A third are plagued by “junk sleep,” or slumber compromised by the constant presence of electronic gadgetry.
But 70 million Americans also have sleep problems, and two-thirds don’t get enough sleep, according to the D.C.-based National Sleep Foundation. These vexing problems ultimately cost the nation about $100 billion a year in lost productivity, medical expenses and other factors.
Still, Americans seem to fall right into the new sleep ideal. The group also reports that Americans average between 6.9 hours of sleep on weeknights and 7.5 hours on weekends. Before Thomas Edison invented the light bulb, people slept 10 hours a night.
Most research about the current epidemic of insomnia and other disorders emphasizes the negative health effects — from compromised job and classroom performance to an increased tendency for obesity, diabetes, hypertension and a weakened immune system.
But one University of Missouri researcher found in January that a lack of sleep may give people an edge. In a study of more than 2,500 patients, Dr. Daniel C. Vinson, professor of community and family medicine, found that patients who reported feeling sleepy were, surprisingly, less likely to be injured.
“It could be that people who feel sleepy change their behavior,” Dr. Vinson said. “If I’m feeling really tired, maybe I’ll stop driving, maybe I won’t play sports. If we’re changing what we’re doing when we’re feeling tired, that may be what lowers our risk of injury.”