Nighttime Light Exposure: How you spend the night sleeping whether with the light on or off, could actually determine how long you live. A new study published in JAMA Network Open finds that turning off the lights at night is not just good for a restful sleep, but it could lower the risk for cardiovascular disease, which is a top cause of death worldwide. What Did The Study Find?The new research found that people who slept in the brightest conditions, especially with having overhead bedroom lights on, had a 56% greater risk of developing heart failure. Those who slept under such an intense light also had a 32% increased risk of coronary artery disease and a 28% increase of stroke. Also Read: The 'BEFAST' Trick Could Help You Detect Your Stroke Before It Happens, According To DoctorHow Was The Study Conducted?The study tracked its participants through wrist wearable. The exposure to light intensity between 12.30am to 6am was measured, as said by Dr Daniel Windred, co-first author of the study. He is a research associate at Flinders University's College of Medicine and Public Health in Australia. “One limitation is that we do not know the sources of personal light exposure, only the intensity,” said Windred. “Understanding typical sources of night light exposure might allow for more informed recommendations beyond ‘avoid bright light at night.’”The study analyzed 13 million hours of light data, which came from 89,000 people. Why Does Turning The Light Off At Night Protects You From Cardiovascular Diseases?The explanation lies in the brain's production of sleep-inducing hormone melatonin, which can be blocked by the light. This is why reducing light exposure at night could make you sleep better. It also means to limit screen time as much as possible and switch off unnecessary household lights within four hours of bed time. Windred says that if turning the light off is not possible, you may try to dim it down or use warm lighting, instead of bright overhead lights. Another thing that must be followed is to avoid using bright alarm clocks, and sleeping near windows, as lights could come through that. In case that too is not possible, you may use light-blocking window shades, or blackout curtains, and even your sleep mask on your eyes.Also Read: 'Felt Like Losing Control Of My Mind, And Sense Of Self', Reveals RTE Star Lottie Ryan About Her Perimenopause Experience Circadian rhythms are 24-hour cycles "in virtually every cell and tissue in our body, including our cardiovascular system," said Windred. This internal clock helps you sleep and also wake up, especially by detecting light as a signal. Disruption of circadian rhythms by light has been shown to interfere with several cardiovascular and metabolic processes, in many earlier studies too. It can damage cells that support healthy artery function, contribute to high blood pressure, and raise the risk of related diseases. Such circadian disruption may also increase the likelihood of blood clots, potentially triggering strokes or heart attacks.Limitation Of The StudyWhile the study did find that exposed to brightest light had a 47% greater risk of having a heart attack, and a 32% increased risk of developing atrial fibrillation. The study did not prove light exposure cause cardiovascular issues, it only showed the link. “There may be other differences in people exposed to light at night that are responsible for the greater risk of heart disease,” said Dr. Tim Chico, professor of cardiovascular medicine at the University of Sheffield in England, in a statement provided by the Science Media Centre. Chico wasn’t involved in the research.