Health disadvantages of daylight savings time (DST)

3 mins read

Over a quarter of the world population is subjected to the daylight saving time (DST) shift twice a year, which disrupts both human work and rest schedules and possibly the body’s biological clock. Several clinical studies have reported an increased risk of cerebrovascular and cardiovascular problems with DST shifts but little is known about other potential health effects.

The idea of introducing daylight saving time (DST) was attractive at the time of candles and gas lamps, as it allowed workers to use sunlight a bit longer during working hours as well as saving employers’ energy for lighting. Much has changed since then. Today, only a small fraction of electricity expenditure actually corresponds to producing light after sunset.

The transition to daylight saving time (DST) is beneficial for energy conservation but at the same time it has been reported to increase the risk of cerebrovascular and cardiovascular problems. Four prominent elevated risk clusters, including cardiovascular diseases (such as heart attacks), injuries, mental and behavioral disorders, and immune-related diseases such as noninfective enteritis and colitis to be significantly associated with DST shifts in the United States and Sweden ( study). While the majority of disease risk elevations are modest (a few percent), a considerable number of diseases exhibit an approximately ten percent relative risk increase. It is estimated that each spring DST shift is associated with negative health effects–with 150,000 incidences in the US, and 880,000 globally.

Interestingly, it has been recently identified that a collection of diseases with relative risks that appear to decrease immediately after the spring DST shift, enriched with infections and immune system-related maladies. 

Insight has been gained into the importance of keeping a healthy biological clock as a way to prevent, slow down, and even treat disease. And as we do, it is becoming clear that the chronic health effects of DST speak to a larger issue, which is that disrupting the body’s natural rhythm negatively affects our health.

One study has also shown that people can not ever really adjust to DST, and that it interferes with our natural adaptation to the changing seasons. These acute effects permeate society and have both economic and physical costs to those who inhabit places that use DST.

There are negative health consequences to using DST, with very little benefit. Changing to year-round standard time is a relatively simple yet profoundly effective way to give people a chance to keep up a more coordinated biological clock.

Experts who have been studying biological clocks for decades agree. So when “falling back” November 1, 2020, let’s hope that one day we will never have to spring forward again.


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