Study Links Low Light Exposure During Sleep to Increased Heart Disease Risk
A new study has found that even minimal light exposure during sleep can alter the shape and function of heart muscles, potentially increasing the risk of future heart disease. The research, published in the European Heart Journal, analyzed data from over 11,000 individuals without pre-existing cardiovascular disease from the UK Biobank study. Participants wore wrist sensors for seven days to measure nighttime light levels, and three years later, underwent cardiovascular MRIs to assess heart structure and function. The study revealed that exposure to more than 3 lux of light while sleeping, equivalent to moonlight or light seeping under a closed door, led to a thickening of the left ventricle walls and a reduction in the heart muscle's ability to flex efficiently. This cardiac remodeling, which can lead to heart failure, worsened with increased brightness in the bedroom. Sources of this light included smartphone glows, digital alarm clocks, and external light pollution.
