New Study Links Excessive Nighttime Light Exposure to Increased Cardiovascular Risks
A large-scale study demonstrates that excessive nighttime light exposure significantly raises cardiovascular disease risks, urging people to limit bedroom lighting at night.
- • Study involved 88,905 adults over 40 wearing light sensors to measure nighttime exposure.
- • High nighttime light exposure linked to 45-56% higher risk of heart attacks and heart failure.
- • Risk of stroke and coronary heart disease increased by 28-30% with bright nighttime lighting.
- • Excessive light disrupts biological circadian rhythms affecting cardiovascular health.
Key details
A groundbreaking study published in "JAMA Network Open" reveals that exposure to excessive light during nighttime significantly raises the risk of developing cardiovascular diseases. The research, focusing on 88,905 adults aged over 40, found that individuals with high nighttime light exposure faced a 45 to 56 percent greater risk of heart attacks and heart failure compared to those with minimal exposure. Risks for stroke and coronary heart disease also increased by 28 to 30 percent among those with brightly lit bedrooms.
The extensive study was conducted by a team led by Daniel Windred and Angus Burns, who equipped participants with wrist-worn light sensors for one week, accumulating over 13 million hours of data. Over nearly a decade of medical follow-up, the researchers observed these significant increases in cardiovascular risk.
Using satellite data, the study highlighted an alarming 50 percent increase in global nighttime lighting from 1992 to 2017, especially in urban areas. Despite accounting for lifestyle factors such as smoking, alcohol use, diet, and sleep duration, the association between nighttime light exposure and cardiovascular diseases remained robust.
Experts attribute these health effects to the disruption of the body’s natural 24-hour biological rhythm caused by excessive light at night, which affects sleep quality, metabolism, hormone production, and body temperature. Jonathan Cedernaes from Uppsala University noted that irregular sleep patterns, known as "social jetlag," are widespread and may worsen these health consequences.
While the predominantly white, higher socioeconomic status study population may limit universal applicability, researchers advise mitigating risks by reducing nighttime light exposure through measures like blackout curtains and turning off electronic devices before bedtime.
This research underscores an urgent public health concern amid increasingly illuminated urban environments and highlights practical steps individuals can take to protect their heart health.