Time to change? Study shows changing the clocks behind massive stroke and obesity levels

Policy changes could reduce serious illness in hundreds of thousands of peopel according to research

View 2 Images

Is time almost up for our long-standing tradition of changing the clocks?

There are many who will relish an extra hour in bed this Sunday October 26th when “daylight saving time” officially ends with the winding back of the hour and the resumption of winter’s “standard time.”

But a new study suggests the twice a year practice could be behind a staggering number of strokes and could also be helping to fuel the obesity epidemic.

And this week it was raised once again on the floor of the European Parliament where some Irish MEPs want to see it abolished.

The parliament has already chosen its side in the great debate by voting for an end to clock changes proposed by the European Commission in 2019.

But the Covid pandemic meant the proposal was shelved for several years by state leaders and ministers at EU Council level.

Brexit also led to Irish fears that if the EU ended the practice, the Republic and Northern Ireland could end up in different time zones for half the year.

However Ireland South MEP Cynthia Ní Mhurchú is again calling for an end to the long-running delays in scrapping the biannual clock change.

“Europeans have spoken clearly — they want the clock-changing to end. The European Parliament voted for it, but the Council has dragged its feet for six years. It’s time to move forward and give people the certainty they deserve,” the MEP said.

In 2018, the European Commission proposed ending the twice-yearly time changes after a landmark public consultation that drew 4.6 million responses, with 84% of participants in favour of abolition.

On Thursday, MEPs pressed the Commission and the Danish EU Presidency to explain what is blocking progress and to outline a roadmap for breaking the deadlock.

Under current rules, EU countries move clocks forward on the last Sunday in March and back on the last Sunday in October.

“This is about wellbeing, safety, and a more sensible Europe. There’s no reason to keep people in the dark — literally or politically,” Ms Ní Mhurchú said.

One hold up is the dispute over whether to stay in permanent standard time, which would mean more light in the mornings through winter, or to have permanent daylight saving time to keep the “grand stetch” in the evenings particularly in summer.

A major new medical study suggests either would be better for our health than the status quo.

Scientists from Stanford University in the US, compared how three different time policies — permanent standard time, permanent daylight-saving time and biannual shifting — could affect people’s circadian rhythms - the body’s innate, roughly 24-hour clock, which regulates many physiological processes.

The team found that either permanent standard time or permanent daylight-saving time would be healthier than our seasonal dithering - with permanent standard time benefitting the most people.

View 2 Images

The researchers estimate that permanent standard time would prevent some 300,000 cases of stroke per year and result in 2.6 million fewer people having obesity in the US.

Permanent daylight-saving time would achieve about two-thirds of the same effect.

Judging by the US data, the EU’s larger population could experience even better health outcomes

“We found that staying in standard time or staying in daylight saving time is definitely better than switching twice a year,” said Jamie Zeitzer, PhD, professor of psychiatry and behavioral sciences and senior author of the study published last month in the Proceedings of the National Academy of Sciences.

Proponents of permanent standard time contend that more morning light is optimal for health.

“It’s based on the theory that early morning light is better for our overall health,” Zeitzer said.

“When you get light in the morning, it speeds up the circadian cycle. When you get light in the evening, it slows things down,” Zeitzer said.

“You generally need more morning light and less evening light to keep well synchronized to a 24-hour day.”

An out-of-sync circadian cycle has been associated with a range of poor health outcomes.

“The more light exposure you get at the wrong times, the weaker the circadian clock. All of these things that are downstream — for example, your immune system, your energy — don’t match up quite as well,” Zeitzer said.

The researchers analysed data from the Centers for Disease Control and Prevention to show that permanent standard time would lower the US prevalence of obesity by 0.78 percentage points and the prevalence of stroke by 0.09 percentage points, amounting to 2.6 million fewer people with obesity and 300,000 fewer cases of stroke.

Under permanent daylight time obesity would decrease by 1.7 million people, and stroke by or 220,000 cases.

The researchers admit they didn’t account for many factors that could influence real-life light exposure, including weather, geography and human behaviour.

And no policy will add more light to the dark winter months.

“That’s the sun and the position of Earth,” Zeitzer said. “We can’t do anything about that.”

Something we know in Ireland only too well, whatever the time of year.

Subscribe to our newsletter for the latest news from the Irish Mirror direct to your inbox: Sign up here