What does the switch to Daylight Saving Time do to your body and health?

The clocks spring forward this weekend but your body clock might not necessarily make the same leap and the change to Daylight Saving Time (DST) can affect more than just your sleep.

While the change is meant to facilitate more daylight hours, allowing people more time in the sun, some experts say it discombobulates the body’s natural rhythms.

Patricia Lakin Thomas, professor of biology at York University is researching what the molecular mechanism is that can tell 24-hour time inside of a cell.

She explains that the body’s central clock is set as per sunrise.

“Our central clock is in the base of the brain in the hypothalamus, and it gets light directly from the eyes straight out to that little brain center that controls the clocks all over the rest of your body. So you’ve got clocks in your liver and your guts and your heart and your muscles and everywhere. They have to get information from the brain clock to keep them in step,” she sasys.

“And normally we want to see light at sunrise, which sets our brain clock to light, then it sets the rest of the clocks in the body and everything is synchronized and we can digest our food at the right time and our muscles are ready to go and our hormone levels are doing what they should do.”

When we switch to DST, Thomas says we forcibly put the body into a state of jet lag.

“We make ourselves wake up at a time when our body isn’t ready … if we’re forcing ourselves to do that by changing our social clock, that is we reset the clock on the wall, we give ourselves ‘social jet lag’ as if we’d flown across time zones,” she says.

Biological functions are disturbed by the switch to DST

“Think about what happens when you feel jet lag. You may not be digesting your food very well because you’re eating at the wrong time. You might not have the energy level that you expect and you’re going to feel a bit sleep deprived as well, and all of the feelings that go along with that,” says Thomas.

“It’s going to be a lot of different things for different people, but generally feeling not on top of things and not feeling those peaks of energy when you expect them to be there.”

She says it becomes apparent that people are not functioning at there best because there are increases in car accidents, acute health events like heart attacks and strokes and an increase in workplace accidents.

“There’s even some evidence that judges give longer sentences to criminals just after the time change. They could be sleep deprived and grumpy, or it might be the ‘jet lag’ altering their judgment in some way,” she says.

If DST was permanently adopted, Thomas says everyone would be an hour jet-lagged, all year round.

She says that could lead to an increase in chronic diseases like diabetes, cancer, heart disease and an uptick in obesity rates.

“We have some evidence that comes from studies looking at people who live on either side of a time zone. And a very clever study was done in the United States where they looked at the edges of time zones … and they looked at people who live on either side of a time zone. So you’re either on the west side of this time zone or you’re on the east side of this time zone. You are living an hour apart from your neighbors, but you’re in the same neighbourhood, same economy, same environment, etc.,” she explains.

When health records were compared, the study showed that those who were following DST were losing an average of 19 minutes of sleep a day and had worse health outcomes than those who were following standard time, as based on the sun.

“They had elevated rates of chronic diseases — heart disease, obesity, even cancer rates went up. They even lost a little bit in their income — 3 per cent lower per person — just because they were on the wrong side of a time zone boundary. So we can pretty well predict if we go to DST [permanently], everybody is going to be in the same situation of being an hour jet lagged all the time. And we can expect somewhat elevated rates of all those chronic diseases and even an economic impact,” says Thomas.

The case for scrapping Daylight Saving Time

Thomas is member of the Canadian Society for Chronobiology — an organization of scientists all across Canada who study biological clocks and agree that twice a year time changes should be scrapped, with a permanent move to Standard Time.

“It sounds nice to have some extra sun on a sunny summer afternoon if [for example] you’re a golfer and want to get a little extra time out on the golf course. Not many people are that privileged to be able to go out, get a little extra sun,” she says.

She adds that the extra hour of sunshine may seem like a good idea, but it also leads to people staying up later and losing sleeping hours.

“We should be thinking about the people it’s really going to impact. And those are the people on a cold winter morning who, in Toronto, aren’t going to see the sun until 9:00 a.m. Those are the people — like mothers trying to get their kids out of bed and go to school, the essential workers trying to get on public transit in total darkness and get to their essential jobs — who are really feel the impact,” says Thomas.

“Under standard time, when the clock says 12 o’clock, the sun is at the highest point of the sky and we want to put our body clocks in sync with the sun [because] … our bodies, which are set by sunrise, will be better in sync and we won’t have any of these long-term chronic effects that we would have under year round daylight saving time.”

“Ideally we would all follow the sun, scrap our clocks, and do what they did in the Middle Ages, before we had regulated clocks, do what farmers do, and get up with the sun. People in cultures that don’t have electricity don’t bother with clocks. That would be ideal. We can’t do that, but we can get rid of Daylight Saving.”

How to mitigate the impacts of the time change

While DST continues to be observed, Thomas says there are a few ways you can mitigate its impacts and get back on track sooner.

She says ideally, people should start going to bed 15 to 20 minutes earlier in the days leading up to the time change.

“But nobody can be that well organized to do that … [so] I think the best thing to do is get out in the morning and get the sunlight, get your brain synced with the sun as soon as you can early in the morning at sunrise,” she says.

Along with that, she suggests paying special attention to meal times and ensuring you eat on schedule

“Because we now know that food can synchronize your liver and your guts separately from your brain. So you want to get your eating schedules regular and move them to the new time as soon as possible,” she says.

In addition, she says exercise in the morning hours is a good way to reset your clock.

“It will take us a few days for everything in the body to reset itself as they all reset at a different rate. And that’s why we feel out of sorts. Literally part of us is in one time zone and other parts in another time zone. So basically get on the new time with a strict schedule as soon as you can and try to get all of those internal clocks resynchronized with not only the sunlight, but also your feeding and your activity rhythms,” she says.