Turn Back the Clock to Improve Your Health

When you set your clock back an hour on Sunday evening, you may just be doing your health a favor as well…at least in the short term. A new study shows that the number of heart attacks declines the day after daylight savings time ends and people set their clocks back an hour. The conjecture is that the extra hour of sleep is enough to have real benefits. "Sleep – through a variety of mechanisms – affects our cardiovascular health," notes Dr. Lori Mosca, the Director of Preventative Cardiology at New York-Presbyterian Hospital. "Sleep not only impacts how we feel, but it may also affect whether we develop heart disease or not."

The study itself, which was detailed in a letter published in the New England Journal of Medicine by Drs. Imre Janszky of the Karolinska Institute and Rickard Ljung of Sweden’s National Board of Health and Welfare. "I was on the bus, quite sleepy, and I thought of this," notes Janszky. The two doctors’ study indicates that during the week after Daylight Savings begins, and clocks are pushed forward by an hour – resulting in a temporarily "lost" hour – there was a 5% increase in heart attacks. At the end of Daylight Savings, when the temporarily lost hour is regained, heart attacks remained the same except for the day after – Monday – during which there was a 5% decrease. The study period included the year 1987 through 2006.

Though the study doesn’t go so far as to suggest an end to changing the clock during the autumn and spring, some doctors are recommending a specific approach to dealing with the one hour time changes that occur during the "spring forward" and "fall back" times. Dr. Ronald Chervin, who specializes in sleep disorders, recommends taking advantage of the extra hour of time in autumn by sleeping (and, perhaps, saving one’s self from a heart attack). Conversely, more planning is needed during the spring, when he recommends adjusting to the time change gradually by going to bed and awaking 15 minutes earlier for several days before the actual time change occurs.