Changing clocks twice a year could be putting 300,000 Americans at risk of a potentially fatal stroke each year.
A new study, conducted by Stanford Medicine researchers, found that switching between Daylight Saving Time (DST) and Standard Time (SDT) disrupted the body’s internal clock by forcing it to adjust too often to changes in light and darkness.
Daylight Saving Time is when clocks are set forward one hour in the spring to give more evening light, and set back one hour in the fall to return to Standard Time.
The next change is set for November 2, 2025, at 2am in each time zone.
However, scientists discovered that this disruption weakens the circadian rhythm, the body’s internal 24-hour clock that relies on morning light to regulate your bodily functions and stay healthy.
While simulating what would happen the US decided to make SDT permanent after ‘falling back’ in November, estimates showed the change could prevent about 300,000 stroke cases annually by reducing this circadian strain.
Switching to permanent DST was less effective because it prioritized evening light over morning light, but it still prevented around 220,000 strokes compared to constantly resetting the clocks every few months.
Dr Jamie Zeitzer, a professor of psychiatry and behavioral sciences, said: ‘Staying in standard time or staying in daylight saving time is definitely better than switching twice a year.’
As the clocks are set to fall backwards, a new study warns the practice could lead to a fatal stroke (Stock Image)
A stroke takes place when there’s a blockage in the brain or a blood vessel bursts, a condition that kills nearly 200,000 people in the US annually (Stock Image)
A stroke occurs when blood flow to the brain is blocked or a blood vessel bursts, damaging brain cells and potentially causing death.
According to the CDC, about 795,000 strokes occur annually in the US, with 185,000 being fatal.
The strain changing clocks puts on circadian rhythms can lead to strokes by increasing blood pressure and inflammation in the brain.
Since the sudden one-hour shifts forces the internal clock to adjust unnaturally, the body struggles to maintain its natural processes, especially when light exposure is misaligned in the morning and evening.
Zeitzer and co-study author Lara Weed, a graduate student in bioengineering, found this misalignment caused an increasing ‘circadian burden’ of adjustment each year.
Circadian burden refers to the total amount of adjustment or ‘shifting’ that the body’s internal 24-hour clock must undergo to stay synchronized with a person’s everyday environment.
This burden was measured in hours over a year and reflected how much the body’s natural clock has to adapt to align with the regular schedules of society, such as work routines or school schedules.
The biannual switching (BAS) added the most strain (21 hours) compared to permanent Standard Time (18.5 hours) or Daylight Saving Time (19.6 hours).
Numerous studies have also linked the start of daylight saving time in the spring with a brief spike in car accidents, likely due to sleep loss (Stock Image)
‘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 explained in a university release.
The study also found that stopping clock changes could lower obesity rates, cutting the widespread health problem by 2.6 million cases if the country stuck to Standard Time and 1.7 million cases under permanent DST.
However, the findings, published in Proceedings of the National Academy of Sciences, noted that there was no significant link between time policy changes and other health conditions such as arthritis, cancer, heart disease, or depression.
This isn’t the first study to warn of the impact changing the clocks twice a year has on the human body.
Earlier this year, top scientists in the UK called for an end to Daylight Saving Time amid fears it fuels a rise in cancer, traffic accidents, and suicide attempts.
A statement by the British Sleep Society highlighted some of the worrying side-effects of changing the clocks.
Losing an hour of sleep when the clocks move forward was found to result in populations feeling more tired than usual.
Some studies have suggested that the risk of fatal traffic accidents increased by around six percent following the spring DST transition.
The UK researchers also revealed evidence of an increased risk of cardiovascular events, increased risk of suicidal behaviors, and increased death rates in the days immediately after switching our clocks.
This article was originally published by a www.dailymail.co.uk . Read the Original article here. .