"Could This Common Sleep Mistake Boost Your Heart Disease Risk by 50%? Find Out if You're Affected!"

DO YOU fall asleep with the TV on or use a night light?

Sleeping with the light on might scare away monsters under the bed.

Study participants who had the highest light exposure were 56 per cent more likely to develop heart failureCredit: Getty

But being exposed to bright light could raise your risk of dying from heart disease, research claims.

US and Australian scientists, who tracked almost 90,000 Brits, said that the disruption light causes to the body’s natural clock, known as , could be deadly to the heart.

They were given wrist-worn light sensors to wear as they slept.

Over a follow-up of almost a decade, researchers mapped their light exposure during the night to diagnoses of different types of , including coronary artery disease, , heart failure, atrial fibrillation and .

Those who were exposed to more light at night were found to be at higher risk of developing all five conditions, regardless of the length or quality of their sleep.

Participants who had the highest light exposure were 56 per cent more likely to develop heart failure, and 47 per cent more likely to have a heart attack, compared to those who snoozed in darkness.

They were also 32 per cent more likely to develop coronary artery disease and 30 per cent more likely to have a .

Women with high night-light exposure were more likely to experience than men, the scientists also found.

Writing in the journal JAMA Network Open , the scientists said: “Night light exposure was a significant risk factor for developing cardiovascular diseases over 40s.

“Avoiding light at night may be a useful strategy for reducing risks of cardiovascular diseases.”

Professor Frank Scheer, a neuroscientist at Brigham and Women’s Hospital in Boston and study co-author, also said: “For something like light exposure at night, there’s no downside to keeping it dark other than using a dim light for safely getting out of bed.

“If you have somebody who’s at risk for cardiovascular disease or somebody who has , asking patients about their light-at-night exposure and recommending to keep it dark might be especially important.

“It doesn’t necessarily need to be pitch-dark.

“When you think about the circadian system, we know what intensity of light people’s clocks respond to.

“If you keep light really dim, below five lux, which is the equivalent of five candles at arm’s length, you can still see your surroundings, but it has minimal effect on your circadian system.”

Dr Daniel Windred, a research associate in sleep at Flinders University in Adelaide, added: “We thought there’d be some effect, but to see close to a 60 per cent increased risk of heart failure with bright night light, the strength of the effect was surprising.

“We’re starting to get up there with other risk factors in terms of how significant it is.

“Our thinking is that the light disrupts circadian rhythms, which leads to a dysregulated physiological state.

“If you disrupt these rhythms over a long enough period of time, chronically, you possibly elevate people’s risk of cardiovascular diseases.”

People often take around 10 to 20 minutes normally to nod off after turning off the lights, the Sleep Foundation say.

In 2024, a study found that around one in six , yet 65 per cent never seek help for their sleep problem.

The poll of 2,000 people, by The Sleep , found nine in ten experience some sort of sleep problem, while one in two engage in high-risk or dangerous behaviours when unable to sleep.

Experts have long advised that waking up during the night does not necessarily mean you have insomnia, which figures suggest affects up to 14million Brits.

Still, sleep , from irritability and reduced focus in the short term, to an increased risk of and .