"Turn off the lights to reduce the risk of heart attack and stroke"
Bright lights at night may increase the risk of heart attack or stroke, according to a new study. Researchers have found that exposure to high levels of artificial light pollution after dark is linked to increased stress-related activity in the brain, inflammation of the arteries and a higher risk of heart disease.
FIRST OF ITS KIND RESEARCHNighttime light pollution is a ubiquitous problem in modern cities. This first-of-its-kind study, using brain scans and satellite imagery, has shown a "biological pathway" between nighttime light exposure and heart disease.
"We know that environmental factors like air and noise pollution can affect our nerves and blood vessels through stress, leading to heart disease. Light pollution is very common, but we don't know much about how it affects the heart," said Dr. Shady Abohashem, a professor at Harvard Medical School and a fellow at Massachusetts General Hospital.
The study involved 466 adults, with an average age of 55, who initially had no heart disease or cancer. The amount of nighttime light in each participant's home, stress signals in the brain and signs of arterial inflammation in scans were measured.
During the study, 79 participants (17 percent) experienced serious heart problems. All participants underwent identical positron emission tomography/computed tomography (PET/CT) scans between 2005 and 2008 and were followed until the end of 2018.
Dr. Abohashem said: “This is an imaging test routinely performed at our hospital. The CT portion provides detailed anatomical information, while the PET portion reveals metabolic activity in tissues. Using both imaging techniques together makes it possible to measure brain stress activity and arterial inflammation in a single scan.”
THE INCREASED EXPOSURE TO ARTIFICIAL LIGHT, THE HIGHER THE RISK OF DEVELOPING HEART DISEASEThe analysis revealed that people exposed to higher levels of artificial light at night had higher brain stress activity, blood vessel inflammation, and a higher risk of serious heart problems. The greater the exposure to artificial light at night, the higher the risk of developing heart disease.
Risks were higher among participants living in areas exposed to additional social or environmental stressors, such as high traffic noise or low neighborhood income. "We found an almost linear relationship between nightlight exposure and heart disease," Dr. Abohashem said. "The greater the nightlight exposure, the higher the risk."
"Even modest increases in nighttime light were linked to increased stress on the brain and arteries," Abohashem continued. "When the brain perceives stress, it activates signals that can trigger an immune response and inflame blood vessels. Over time, this process can contribute to hardening of the arteries and increase the risk of heart attack and stroke."
"UNNECESSARY OUTDOOR LIGHTING IN CITIES SHOULD BE REDUCED"To counter the effects of artificial light at night, Abohashem suggested that cities reduce unnecessary outdoor lighting, maintain streetlights, or use motion-sensitive lights.
"This research shows that light pollution is not just a nuisance but may also increase the risk of heart disease," Dr. Abohashem said. "We hope clinicians and policymakers consider nighttime light exposure when developing prevention strategies. We want to expand this study to larger and more diverse populations, test interventions that reduce nighttime light, and investigate how reducing light exposure can improve heart health. People can limit nighttime light indoors by keeping their bedrooms dark and avoiding screens like televisions and personal electronic devices before bed."
Habertürk
