Study: Nighttime light exposure may alter heart shape
New research links light exposure during sleep to cardiac remodeling, potentially weakening heart function. Over 3 lux of light at night was significantly associated with thickening of the heart's ventricle wall.
A new study has found a link between exposure to light and changes in the heart's structure during sleep. Research led by Tulane University and published in the European Heart Journal suggests that nighttime light exposure can lead to thickening of the left ventricle wall, reducing the chamber's internal space and impairing its pumping ability.
The study analyzed the sleep habits and heart structure of over 11,000 participants. Subjects wore wrist-worn light sensors for seven nights. Three years later, their hearts were scanned via MRI to assess structure and function. Results indicated that those exposed to more than 3 lux of light overnight showed significantly more cardiac remodeling compared to individuals who slept in near-complete darkness.
Three lux is equivalent to the brightness of deep twilight, while a phone screen can reach approximately 80 lux. Given that a substantial portion of the population uses screen devices shortly before bed or in bed, many may be unknowingly exposing themselves to harmful light during sleep. The researchers emphasize that reducing light pollution should be considered a strategy for preventing heart disease.
Experts recommend using blackout curtains, sleep masks, and covering small standby lights on electronic devices during sleep. Limiting screen time immediately before bed is also crucial. Cardiologists are urging healthcare providers to inquire about patients' sleep environments as part of cardiovascular health assessments, recognizing darkness as a vital factor for heart health.