by Rachel Stockton

Created on: March 10, 2009   Last Updated: March 11, 2013

At first glance, the effect of Daylight Saving Time (DST) on the health of the general population would seem to be nominal. However, there have been some studies in this regard, and although much of the time the information that results has been nebulous and somewhat contradictory, there are some patterns which are worth noting.

Circadian Rhythm Fluctuation

First and foremost, there are some "inconveniences" regarding the shifting of our circadian rhythms when the time is suddenly changed. For some, the adjustment period can last for weeks. When the body's inner clock is abruptly unable to sync up with its external environment, fatigue, sleeplessness, irritability and other discomforts can occur. Hormonal changes, brain wave activity and even cell regeneration tend to occur at the same time every day; toying with this rhythm can bring on a feeling of dysphoria at best, depression at worst.

On the flip side of the depression coin, some believe that DST can actually help alleviate the disorder, as people must get up earlier once the time changes. Then, there is the condition known as SAD (seasonal affective disorder), which affects some people more severely than others. A study in 2008 seems to support this, as male suicide rates increase the first few weeks after the spring transition from standard time to DST.

According to a recent article published in the New York Times, 55,000 workers were tracked over a period of time to study time affects on their circadian rhythms. It was found that when these employees enjoyed days off, their bodies were more on a standard time schedule than a DST schedule. Furthermore, in the spring, their peak activity levels were associated with their body clocks, not the clock on the wall. Although researchers say more study is needed, there's also been a correlation between DST and higher suicide and accident rates.

Other Health Issues

A Swedish study revealed that heart attacks increase somewhat the first 2-3 workdays after the spring transition. Research has revealed that people are more prone to heart attacks the first hour after they wake up; the added stress of having to wake up one hour earlier could contribute to this rate increase.

As far as overall health and conditioning, one could also assert that DST can indirectly improve one's overall health because of the fact that the extra hours of daylight at the end of the workday could inspire some to exercise more out of doors.

Additionally, trips to the gym after work might also increase during the summer. Women, who tend to stay in on those evenings that turn dark early more than they do on summer evenings, might even be more inclined to visit the health club during DST, as they don't have to worry about dark parking lots and the dangers that lurk there.

Those who suffer from night blindness also experience relief during the summer months; this could be one reason why traffic fatalities decrease during DST. Night blindness can range from mild instances in which headlights tend to be exaggerated to the sufferer, to more severe instances where the driver actually has double vision.

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