Nighttime light exposure and TV habits linked to changes in heart health

Sleeping with a television on or facing other nighttime light sources may affect your heart health by disrupting the body clock. A recent study published in the European Heart Journal followed 11,071 UK Biobank participants who wore wrist light sensors. About three years after wearing the devices, these participants underwent cardiovascular MRI scans to check their heart structure and function.

Findings And Causes

The study found that greater exposure to light at night relates to measurable differences in heart structure and function. Shorter sleep duration explained a large part of this link, with researchers estimating that reduced sleep mediated roughly 24 percent to 49 percent of the observed heart changes. Dr Anil (Col) Dhall, Head of the Department of Cardiology at Shalby International Hospital in Gurgaon, notes that even minimal light exposure can affect the body, and the issue extends beyond television viewing to include streetlights, lamps, and other artificial lights. He explains that the core concern is the disruption of the natural nighttime environment, which disturbs sleep and affects the body clock.

Prevention And Context

Experts suggest setting a sleep timer on the television rather than letting it play all night if you use it to fall asleep. You can also keep unnecessary lights off, limit screen time near bedtime, and use blinds or curtains to block bright outdoor light. Nighttime light exposure interferes with the body's circadian rhythm, which normally uses darkness to trigger the release of melatonin, a hormone that regulates sleep.