There is “very clear evidence” that the biannual clock change is bad for our health, according to Professor Luke O’Neill.

The clocks will spring forward at 1am this Sunday – meaning we will lose an hour as we move into the summer time period.

In the short-term, the change will mean darker mornings and brighter evenings for people travelling to school and office-hour jobs.

The change, known as daylight savings, was first introduced in 1916 Germany as an energy-saving measure during World War I.

Britain introduced the change the same year – and went further in Ireland, abolishing Dublin Mean Time (DMT), which was 25 minutes behind London, and synchronising Ireland and Britain in the same time zone for the first time.

As a result, when British clocks went back by an hour in winter 1916, Irish clocks went back by 35 minutes and have remained on Greenwich Mean Time (GMT) ever since.

The US introduced the measure in 1918 and now, around one-third of the world's countries follow some form of daylight savings system.

The European Parliament has already voted to abolish daylight savings altogether, with countries due to remain on ‘summer time’ all year round; however, despite the vote passing in 2021, nothing has happened in the years since.

In Ireland, the Government has made it clear that we will not be making any change that puts Dublin in a different time zone to Belfast.

Daylight savings

On The Pat Kenny Show this morning, Trinity Professor Luke O’Neill said there is “very clear evidence” that changing the clocks is bad for our health.

“You reacclimatise after a few days anyway, but in that period, say a few days after the clock changes, there is an increased risk of various things like heart attacks - that is very clear - and stroke for example,” he said.

“Just because we're slightly out of sync with our biological clock.

“The reason seems to be the immune system doesn't like it, which is what struck me in initially.

“There was one study done [and] you can measure inflammatory proteins in your blood going up soon after the clocks change – there’s some stress on the body.

“That's one thing and those inflammatory proteins might increase your risk of a heart attack.

“Then there is colitis, the symptoms are worse, they've shown, after the clocks change as well, because of this inflammatory process.”

Health

Prof O’Neill said there is an impact regardless of whether the clocks are going forward or back.

Meanwhile, there are also studies showing the change can make the roads more dangerous.

“That was a serious one,” said Prof O’Neill. “There's a 6% increased risk of fatal car crashes in the days after the clock change.

“That’s a really interesting number. It doesn't sound like very much but still that's a 6% difference.

“So one lobby is saying, if we stop doing it, we'll decrease the risk of fatal car crashes in the days after the clocks change, and that in itself could justify this.”

Immune system

Prof O’Neill said there are also studies showing your body is better able to fight infections in the days after the change.

“They've shown this statistically,” he said. “It was a huge study, over 100 million health records in America were examined for this, that's probably pretty robust.

“So, it looks as if your immune system is slightly up a few days after - because your body is under stress is the idea - and if you get an infection, you can fight it better.

“But unfortunately, if you've got colitis, the immune system is again overactive and makes the symptoms worse.

“So, there's all this evidence that it's bad for our health in those few days.”

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