The habit of turning on lights when sleeping is quite common, especially in big cities. However, a new study by Harvard University shows that this habit can negatively affect cardiovascular health.
According to research results, people who are exposed to light while sleeping have a 50% higher risk of cardiovascular disease than people who sleep in the dark. Notably, this risk does not stem from sleeping less, but mainly because light disrupts the circadian rhythm, the mechanism that regulates many important functions of the body.
Experts say nighttime light, including light from night lights or electronic devices, can disrupt the natural sleep-wake cycle. When the circadian rhythm is disrupted, the body is not rested and fully recovered, thereby affecting the activity of the heart and blood vessel system.
Dr. Sanjay Bhat, senior counselor on interventional cardiovascular disease at Aster CMI Hospital (Bangalore, India) said that sleeping with lights on for a long time can increase heart rate, blood pressure and body stress levels. Light when sleeping also affects hormones related to stress and cardiovascular function, increasing the risk of high blood pressure and heart disease.
In addition, sleeping with lights on also affects sleep quality. Light makes it difficult for the sleeper to fall asleep deeply, easily wake up in the middle of the night and not achieve restored sleep. The consequence is prolonged fatigue, reduced concentration and reduced work efficiency during the day.
According to Dr. Bhat, exposure to night light reduces melatonin production, a hormone that plays an important role in regulating sleep and protecting cardiovascular health. Prolonged melatonin deficiency can lead to hormonal disorders, increasing the risk of obesity, diabetes, immunodeficiency and affecting mental health.
Some studies also show that sleeping in a light environment is associated with a higher risk of coronary artery disease and stroke. Prolonged poor quality sleep can increase blood pressure, blood sugar disorders and create great pressure on the cardiovascular system.
Conversely, sleeping in a dark room helps the body produce enough melatonin, supports deep sleep and stabilizes blood pressure. A dark and quiet sleeping space helps the heart rest properly, reduces stress and contributes to maintaining long-term cardiovascular health.
Experts recommend turning off lights when sleeping, limiting light from electronic devices and creating a dark, quiet bedroom environment to protect sleep and cardiovascular health.
