Daylight Saving Time and Health: Are You "On The Way"?

March 18, 2011 – Daylight saving time change would impact our health and alertness. In addition to being linked to an increase in cardiovascular disorders, it would also be associated with an increase in road accidents in the following days.

People’s circadian rhythms can be out of order for a few days before adjusting to daylight saving time. In fact, changing the time can disrupt the biological clock of certain hormones in the body, including melatonin, which needs about 2 hours to drop in light to trigger sleep.

Consequently, lack of sleep tends to reduce vigilance and the speed of reflexes in people’s daily activities, including driving their cars.

Circadian rhythms
Circadian rhythms refer to biological events in our body that are repeated every 24 hours. They are generated inside our body and they persist even in the absence of stimuli from outside. However, they can be influenced by the environment, particularly by light. These rhythms are controlled by the biological clock located in the center of the brain at the base of the hypothalamus.

“It is recognized that after a change of time, there may be an increase in the number of accidents lasting 1 to 3 days. This change of time can lead to a certain level of fatigue and lack of attention in some people. While other people will suffer less from it, ”explains Nicolas Cermakian, specialist in circadian rhythms at the Douglas Mental Health University Institute in Montreal.

The few studies that have been published on this phenomenon in recent decades, particularly in the New England Journal of Medicine and in the review Sleep medicine, showed an increased increase in the number of road accidents on Monday after the switch to daylight saving time.

In another study, published in the journal Current Biology, the authors indicated that the biological clock of the human body would have more difficulty adjusting to the change to daylight saving time than to the return to normal time.

The time change could also have effects on mental health. According to an Australian study, the number of suicides is higher in the first weeks after the change to daylight saving time than during the rest of the year.

They are subject to circadian rhythms

The wake-up-sleep cycle. It determines when we feel the call of Morpheus and when the body wants to wake up and get back into action.
Body temperature. It varies by around 1 ° C per day. Normally, it is at its minimum around 4 a.m. and reaches its maximum in the evening.
The production of hormones. Melatonin (which helps to fall asleep), for example, is produced from early in the evening, while the secretion of cortisol and testosterone (which help keep you alert) is highest in the morning.
The mood. The feeling of well-being is usually lower in the early morning hours and gradually increases throughout the day. It usually reaches its highest point in the late evening.
Pain tolerance. It is higher in the afternoon. Dental pain, for example, often seems more bearable in the late afternoon.
the heartbeat, the vigilance and the memory are also subject to circadian rhythms.