Nighttime light exposure damages the heart, study of 11,000 finds
A study of over 11,000 people found that any light above 3 lux during sleep is linked to measurable heart damage.
Sleeping with light on, even dim light from a street lamp, clock radio, or LED, is linked to measurable changes in the heart's structure and function, according to research published in the European Heart Journal.
Doctors studied 11,071 people from the UK Biobank who wore wrist sensors to measure light exposure during sleep, then had heart scans years later. People exposed to the most light had, on average, a 2.4% larger left ventricle, 1.5% thicker heart walls, and 1.9% less ability to contract than those sleeping in darkness.
Research shows that light exposure above at least 3 lux during sleep is linked to measurable, subtle cardiac damage. The changes are small individually but together are significant enough to increase the risk of heart disease and stroke.
- 11,071 participants
- Study size
- 2.4 per cent larger
- Left ventricle enlargement
- 3 lux
- Light threshold
- UK Biobank
- Source
Why it mattersMost people can control bedroom light with cheap fixes, making this actionable information that could lower heart disease risk.
AustraliaAustralians concerned about heart health can reduce risk by blocking light sources at night-street lights, device screens, appliances-without medication or expense.
✓ Claims checked against the source and corrected before publish. checked 11 d ago
