A recent study published in the *Journal of the American Medical Association* (JAMA) has revealed a concerning connection between high levels of artificial light exposure at night and an increased risk of heart disease and breast cancer. Conducted by researchers at Uppsala University, the study indicates that excessive nighttime lighting can elevate the risk of these health issues by as much as 50%.
The research, led by Dr. Jonathan Cedernaes, involved tracking the health of 89,000 participants over a period of one week between 2013 and 2016. Participants were subsequently monitored for health outcomes approximately eight years later. The findings linked higher levels of artificial light at night to increased risks of various cardiovascular conditions, including coronary heart disease, stroke, atrial fibrillation, myocardial infarction, and heart failure.
The implications of this study are significant, as the researchers found that the increased risks persisted even after considering other factors such as sleep duration, sleep efficiency, physical activity, and seasonal photoperiod. Historically, studies have noted the impact of light from devices such as smartphones and televisions on sleep quality. This research extends that understanding, highlighting that broader sources of artificial light can also have detrimental effects on health.
Daytime Light Exposure Benefits
Interestingly, the study also noted that individuals who were exposed to higher levels of daylight had a reduced risk of cardiovascular diseases. According to Dr. Cedernaes, “Just as all light is not uniform, neither are we as individuals.” He emphasized that the intensity of light necessary to significantly suppress evening melatonin secretion can vary greatly among individuals, sometimes differing by several factors.
The research suggests a potential public health message: reducing unnecessary bright lighting at night could be critical in minimizing cardiovascular risks. Optimizing light exposure throughout the 24-hour cycle may help individuals lower their chances of developing serious health conditions.
This study adds to the growing body of evidence regarding the health impacts of artificial light, prompting a reevaluation of lighting practices, particularly in residential and urban environments. As people become increasingly aware of their nighttime surroundings, addressing artificial light exposure may become an essential aspect of public health strategies aimed at improving overall well-being.
