Study warns a lot of health problems if you do THIS one thing before going to bed

For a good night sleep, it is important to turn off the lights or dim the lights (Picture Credit: Pexels)

It might sound almost trivial, your bedside lamp, the glow from your phone, or the streetlight peeping through the curtains. But according to fresh research from Boston, these everyday sources of artificial light could be quietly putting your heart under pressure. Scientists found a nearly linear relationship between night-time light exposure and heart disease risk.

Dr Shady Abohashem, head of cardiac PET/CT imaging trials at Massachusetts General Hospital, says, “Even modest light increases can trigger stress responses in the brain that inflame blood vessels over time.” The recent study, which is soon to be presented at the American Heart Association’s, Scientific Sessions 2025 in New Orleans, tracked 450 adults with no prior heart disease. Using advanced PET/CT scans and satellite data, researchers were able to link higher night-light exposure with increased brain stress signals, inflamed arteries, and a greater likelihood of major heart events. “It’s a first-of-its-kind approach, combining brain imaging with environmental light measurements,” adds Dr Abohashem.

The research suggests that the modern urban lifestyle, lit up by streetlamps, neon signs, and the soft glow of electronic devices, may not just be disturbing your sleep, it’s also subtly nudging your cardiovascular system towards trouble. The effects appear most pronounced in areas with additional stressors, such as high traffic noise or lower neighbourhood income.

More artificial light at night was associated with increased metabolic activity in stress-related brain regions. “The brain interprets this as a threat, activating immune responses that inflame arteries,” explains Dr Abohashem.

The same participants showed signs of blood vessel inflammation, a key step towards atherosclerosis and heart disease.

Statistically, each increase in night-light exposure raised the risk of heart events by about 35% over five years and 22% over ten.

Risk was greater in participants living in high-noise, low-income areas, showing how environmental and social factors can interact to affect health.

Experts suggest dimming indoor lights, keeping bedrooms dark, limiting screen use before bed, shielding street lamps, and using motion-sensor lighting outdoors.

“Light pollution is more than a nuisance, it’s a public health concern,” says Julio Fernandez-Mendoza, professor of psychiatry at Penn State University. This study underscores the importance of circadian health and managing environmental exposures that stress the body.

Dimming lights signals your body to produce melatonin, the hormone that promotes sleep.

It’s best to start dimming lights about 30–60 minutes before bedtime.

Yes, exposure to bright or blue light at night can delay sleep and reduce sleep quality.

Use warm, soft lighting such as lamps or night lights instead of overhead or cool white lights.

Absolutely — softer light helps calm the mind, reduce alertness, and prepare your body for rest.