Why daylight savings is bad for our health

Hi there,

Is anyone else feeling jet-lagged this week, even though you haven’t been anywhere?

In the UK, the clocks went forward an hour on Sunday. There are some benefits to this - lighter summer evenings to spend in beer gardens with friends or go for a run in the park. But it’s also disruptive. We’re tired, which leads us to make mistakes and impacts our mood.

A one hour shift might seem trivial, but the consequences are not.

Light is important in the morning

You’ve probably felt a bit groggy when waking up this week. It might still be dark outside.

Viewing morning light is important in setting our circadian rhythm and helps us sleep better (more on this in last week’s newsletter). It also helps us feel more alert and improves our mood.

Daylight savings reduces our ability to get this crucial morning light, negatively impacting our sleep and morning behaviour.

And harmful in the evening

Viewing light in the evening is disruptive to our circadian rhythm.

It delays the brain’s release of melatonin, a hormone that makes us feel sleepy. We’re likely to have trouble sleeping as a result.

This has a particularly negative impact on teenagers. From puberty into our 20s, melatonin is released later than usual in the evenings. This in combination with daylight savings means adolescents are more likely to experience sleep problems during this time.

Bad things happen when the clocks shift

The daylight savings time shift has been shown to be associated with: an increased occurrence of heart attacks and strokes, and a rise in accidents (particularly car accidents) and workplace injuries.

Why does this happen?

The main explanation is due to a lack of sleep.

Accidents occur because people are tired and aren’t paying attention or making mistakes. Heart attacks and strokes happen because the time shift disrupts our circadian rhythms and causes stress to our bodies. Sleep quality and quantity are lower, inflammation in the body increases, and our heart rate and blood pressure go up.

But there are some benefits

There are two main benefits to moving the clocks forward an hour every spring.

First, several studies have shown that crime rates drop slightly with lighter evenings. The percentage decrease varies across reports - from a 2.9% decrease in assaults to a 7% decrease in theft.

Second, there’s increased economic activity. People are likely to be out and spend more during the lighter evenings.

While these benefits exist, they don’t outweigh the negative impact on our health.

What should we do?

It’s clear we should end the bi-annual time disruption - but which time should we choose?

Permanent standard time (GMT) rather than permanent summer time (BST) is better aligned with our natural circadian rhythm: waking with the sunrise and going to bed in the darkness.

A bill recently passed by the US Senate proposes to make daylight savings time permanent in the US, directly contradicting the science. The bill will now go to the House of Representatives for further consideration.

On the other side of the pond, in 2019 the European Parliament voted to end daylight savings. But it hasn’t happened yet. This decision doesn’t apply to the UK due to Brexit, and Boris Johnson recently stated that it was unlikely that the UK would stop the bi-annual time switching.

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Question of the week

I saw something on Twitter this week about unconventional habits. One of them was: when something unfavourable happens, ask ‘how is this the best thing that ever happened to me?’

The concept of reframing a bad situation to focus on the silver lining reminds me of this Stoic principle:

The chief task in life is simply this: to identify and separate matters so that I can say clearly to myself which are externals not under my control, and which have to do with the choices I actually control. — Epictetus

We don't control what happens. The only thing we can control is how we respond.

With that, my question: How is the daylight savings time shift the best thing that ever happened to you?

Link of the week

So true. Sigh.

That’s all for now. Have a great week!