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09th Nov 2021

Our late night scrolling could be seriously damaging our heart health, scientists say

Katy Brennan

Experts say falling asleep between 10 and 11pm may be the “sweet spot” for maintaining a healthy heart.

Most of us try our best to go to bed at a socially accepted and reasonable hour. But then TikTok calls and you think – “I’ll just have a look.”

Next thing you know you’ve scrolled hours away and a good night’s sleep starts to look increasingly unlikely.

It’s no surprise that this activity, sometimes called doomscrolling, is detrimental to our health – both mentally and physically – and studies in the past been have proven the link between the length of sleep and cardiovascular risks.

But this is the first study to examine health implacations related to the actual time people fall asleep at rather than sleep duration.

In the four-year long study, 88.000 volunteers wore a wrist device which measured the time they fell asleep at over seven days.

In the end, 3,172 participants had developed some kind of heart disease, such as heart attacks, strokes, transient ischaemic attacks and heart failure.

People who had fallen asleep between 10 and 11pm were least likely to have developed heart problems – even after controlling for other variables like duration of sleep, sex, age, and certain other health issues.

“The body has a 24-hour internal clock, called circadian rhythm, that helps regulate physical and mental functioning,” researcher Dr. David Plans from the University of Exeter said.

“While we cannot conclude causation from our study, the results suggest that early or late bedtimes may be more likely to disrupt the body clock, with adverse consequences for cardiovascular health.

“If our findings are confirmed in other studies, sleep timing and basic sleep hygiene could be a low-cost public health target for lowering risk of heart disease.”

According to Regina Giblin, senior cardiac nurse at the British Heart Foundation, falling asleep between 10pm and 11pm could be the “sweet spot for most people to keep their heart healthy long-term”.

“However, it’s important to remember that this study can only show an association and can’t prove cause and effect,” she added.