Monday, November 07, 2011
As the first Monday morning back to work after adjusting the clocks, I thought it fitting to comment on Daylight Savings Time (DST) and its health implications.
Daylight Savings Time began in the United StatesÂ as a way to conserve energy during World War One. ThoughÂ we adopted DST late in the game (1918), we subsequently repealed it in 1919. US presidents "toyed" with DST again through 1974 when Nixon signed it into law as the "Daylight Saving Time Energy Act"
Well, as it turns out, it seems DST does not save energy; in fact, it seems to increase energy costs. In addition to the financial costs associated with DST, there seems to be a very real human cost. In this post, weâ??ll explore some of these issues.
In terms of the human accounting, we all know the joy of â??gaining an extra hourâ? in Fall. That said, we also know the pain of trying to wake up earlier on the first few mornings in Spring when we set the clocks forward. And if you're a parent, you know the struggle of trying to sleep train the kids again (and again). But even more importantly, there is some research which indicates that the disruption in our circadian rhythms can be harmful to our health. OurÂ internal clock sets itself not by the alarm at our bedside but by the movements of the sun. When we disruptÂ our biological rhythms, we really can get ourselves into trouble.
DST is associated with a significantly increased risk of mortality due to heart attacks. The risk is increased for the first 3 weekdays in Spring and the first weekday in Autumn. It turns out that even a seemingly small change inÂ our sleep patterns (especially the sleep deprivation accompanied by the time change in Spring) increases stress hormones and inflammation resulting in increased risk of cardiovascular events.
DST is also associated with increased auto accidents both in Spring and Fall, at least according to some studies.
So what's to gain when we change the clocks? Apparently, not very much!
Indiana took on DST only in 2006. We see that their adoption of DST actually increased average household energy costs by $3.29 a year in comparison with non-DST years. That amounts to an increase of about $9 million per year of added energy costs for the entire state. So while it's true that DST decreases the cost of lighting our homes, it actuallyÂ increases the demand for heating and air conditioning.
Other than lobbying our government to put an end to this failed experiment, we can do something else to help use transition into and out of DST: make it a transition, instead of a "fall" or "spring" into DST. Make the time change more progressive and it will have less of a detrimental effect on your biological clock. Go to sleep and wake up 15 minutes earlier or later during the week before the time change and your body will be more likely to ease into it.
Though this seems to be particularly important in the Spring, some of my readers will ask why I didn't give them advanced notice! The honest truth: that one extra hour afforded by our "fall back" gave me some extra writing time on this 1st Monday morning back in the office!