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A brand new study indicates that where you live in a time zone can reduce how much you sleep, and have general negative impact on health. So, do we actually need time zones?

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Time zones are weird, aren't they? Why do people in one area think it's one time, but people who live only a few miles in one direction or another can think it's another time entirely? Turns out, they may be screwing up our health as well. This is Healthcare Triage News.


To the research!

A new study published in the Jornal of Health Economics, looked at how living on one side or another of a boundary of a time zone affected people's health and economic situations. Specifically, they looked at how sunset time affected those things.

Don't underestimate the power of the sun setting. It's not hard to imagine that over billions of years of evolution, animals, including humans, developed powerful responses to the big ball of fire in the sky, and the only source of light for the vast, vast majority of time, going down each night. As you travel from east to west in a time zone, the time of sunset gets later. That is, until you hit a timezone; then it gets earlier again.

When the sun goes down, hormones from the body get released that can start getting you drowsy. People who live towards the east of a time zone tend to go to bed earlier than those who live on the west, likely because of this.

Data from the American Time Use Survey show that those who live in areas with a later sunset tend to go to bed 19 minutes later on average than those with an earlier sunset. They don't necessarily sleep later, though. You got to get up at the same time for work. That means they get less sleep, and, as we've discussed many times before in previous episodes, less sleep is bad for you.

People who live on the later sunset side of a time zone are more likely to sleep less than 6 hours and less likely to sleep more than 8 hours. People on the later sunset side were more likely to be overweight. In fact, the rate of obesity was 5.6% higher among those on the last sunset side, and that's an absolute difference. They even found higher rates of diabetes, heart attacks, and even breast cancer.

These health problems carry an economic cost as well, of course. Beyond that, there might even be a productivity cost. The researchers found that wages were about 3% lower on the later sunset side.

Some caveats: this study could only look at heavily populated counties, 'cause that's where the data were from. They're also observational, so the casual pathways aren't totally clear.

And, as always, consider the benefits as well. Many people like having some more daylight hours at the end of the day. It gives you more time to relax and enjoy yourself. Joy matters! There's a reason why everyone doesn't move to the eastern side of the time zone. That's ok, trade-offs.

On the other hand, we're doing this to ourselves. Do we need time zones? We could get along just fine without them.


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