Khaberni - An international team of scientists analyzed data from about 89,000 adults who are over 50 years old with an average age of 62, most of them women, to understand the health effects of exposure to bright night light.
The exposure data was collected using wrist-mounted sensors over a week, totaling more than 13 million hours of monitoring. Participants were divided into groups based on their level of light exposure at night. Those exposed to the brightest lights (top 10%) had significantly higher rates of the following:
Coronary artery disease (increase by 32%),
Heart attack (increase by 47%),
Heart failure (increase by 56%),
Arrhythmia disease (increase ranging from 28% to 32%).
These effects persisted even after accounting for factors such as sleep, exercise, food, smoking, genetic factors, and social status.
Researchers found that nighttime light particularly increased the risks for women (heart failure and coronary artery disease) and younger individuals in the group (atrial fibrillation). This is explained by the effect of light on the body's biological clock, as disrupting daily rhythms impacts hormones, metabolism, and blood pressure.
Dr. Daniel Windrid and his colleagues from the Flanders Institute for Health and Medical Research in Australia said, "In addition to usual preventive measures, avoiding light at night could be a useful strategy to reduce cardiovascular risks."
The researchers hope that further research will allow understanding of how much reducing light exposure at night can lower the risk of cardiovascular disease in the long term, and whether there are critical periods in life when this effect is particularly strong.
