Exposure to artificial light at night might be affecting more than just your sleep quality; it could also have implications for your heart health. A study involving over 11,000 adults found that those exposed to higher levels of light during the night had notable differences in heart structure and function. These findings underscore the importance of maintaining a dark sleeping environment for better health.
The research, which involved participants wearing wrist devices to measure light exposure, revealed that increased nighttime light was associated with greater left ventricular mass, thicker heart walls, and reduced ability of the heart muscle to contract. These changes are consistent with concentric cardiac remodeling, a structural change with potential clinical significance. However, it’s important to note that the study does not definitively establish that nighttime light directly causes heart disease.
One possible explanation for these findings is the disruption of sleep. The body’s circadian rhythm, an internal 24-hour clock, regulates sleep and hormone release. Exposure to light at night can interfere with these processes, making restful sleep more difficult. The study indicated that shorter sleep duration partly accounted for the association between nighttime light exposure and changes in heart structure, although other biological mechanisms may also play a role.
Reducing unnecessary light in the bedroom can be a simple yet effective way to improve sleep quality. Practical steps include using a TV sleep timer, turning off unnecessary lights, blocking outdoor light with curtains or blinds, reducing screen use before bed, and maintaining a regular sleep schedule. While these measures are not substitutes for other heart-healthy behaviors, they can contribute to a more restful sleep environment.
Though occasionally falling asleep with the television on might not pose an immediate risk to heart health, consistently sleeping in a brightly lit environment could interfere with healthy sleep patterns. If you have concerns about your heart health, it’s advisable to consult a healthcare professional to discuss your individual risk factors rather than relying solely on changes in sleep habits.