Put the clocks again once more as boffins say darkish days could lead on you to an early grave

Brighter nights and darker days could lead to an early grave, according to scientists. They investigated whether sunrise, sunsets, and bright lights that disrupt our circadian rhythms can increase death.

Research shows that those who were exposed to high levels of light at night had a 21-34% increased risk of death, whilst those exposed to high levels of daylight had a 17-34% reduction in their risk of death.

The findings, published in the Proceedings of the National Academy of Sciences, suggests that light exposure at night disrupts circadian rhythms by shifting the timing and weakening the time our bodies naturally want to go to sleep.

The study authors, from FHMRI Sleep Health, examined the relationship of personal light exposure with different mortality risks in 89,000 UK participants, who were between 40 and 69 years old. Metrics were recorded with wrist worn sensors and mortality was captured by the NHS across eight years.

Measures tracked include sleep duration, sleep efficiency, and mid sleep. Mortality was defined by researchers as any cardio-related death, such as heart disease, high blood pressure, type two diabetes, and obesity.

They found a disrupted circadian rhythm predicted higher mortality risk, which the authors were able to determine using computer modelling.

Professor Sean Cain, a senior author and sleep expert for the paper from Flinders University, told Science Daily: “Exposure to brighter nights and darker days can disrupt our circadian rhythms, a disruption that is known to lead to various health issues including diabetes, obesity, cardiovascular disease, mental health issues and increase the risk of death.”

He said the research may show people the ‘adverse impact’ light may have and how important personal light exposure patterns are for people’s health.

Lead author, Dr Daniel Windred told Science Daily people should prioritise maintaining a dark environment across the late night and early morning hours, when our body clocks are most sensitive to light to get a good night’s sleep.

“Protection of lighting environments may be especially important in those at risk for both circadian disruption and mortality, such as in intensive care or aged-care settings. Across the general population, avoiding night light and seeking day light may lead to reduction in disease burden, especially cardiometabolic diseases, and may increase longevity.”

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