Impact of Artificial Light on Heart Health: New Insights

Artificial Light’s Effects on Heart Structure

A recent study from Tulane University indicates that artificial light at night may do more than interfere with sleep. The European Heart Journal published findings on September 9 suggesting potential links between exposure to artificial light and changes in the heart’s structure and function, which could increase the risk of cardiovascular diseases.

Researchers tracked over 11,000 participants from the UK Biobank, using wrist-worn devices to record nighttime light exposure for seven days. Cardiovascular magnetic resonance (CMR) imaging was then conducted to evaluate heart structure and performance. The data showed participants exposed to higher levels of nighttime light had increased heart muscle mass and thicker heart walls, conditions often preceding cardiovascular diseases.

Dr. Lu Qi, the study’s lead and director of the Tulane University Obesity Research Center, noted that nighttime light exposure might reduce sleep duration and quality. This disruption, he explained, likely affects the body’s circadian rhythm, a natural 24-hour cycle impacting various bodily functions.

“The findings, along with other studies, suggest bedroom lighting is important for cardiovascular health. Turning off light during sleep may benefit the heart,” Qi said.

Understanding Light Pollution

Light pollution involves excessive and unwanted artificial light, commonly originating from streetlights, illuminated buildings, vehicle headlights, electronic devices, and outdoor advertisements. Past studies have linked night light exposure to obesity, hypertension, diabetes, and increased cardiovascular disease risk. These associations are partly due to impaired cardiac autonomic regulation, elevated systemic inflammation, and circadian rhythm disruption.

According to Martin Young from the University of Alabama, circadian clocks are sensitive to environmental factors, especially light. Nighttime light exposure disrupts these clocks, leading to desynchronization between cells and organs.

“Lab-based studies show circadian disruption prevents normal cycles of cellular repair, causing a growth of pathological heart components,” Young explained.

Symptoms of Cardiovascular Diseases

Cardiovascular diseases affect the heart and blood vessels, with symptoms varying by condition. Common signs include:

• Chest pain or discomfort
• Stomach pain similar to indigestion
• Shortness of breath
• Throat tightness
• Dizziness or fainting
• Heart palpitations
• Extreme fatigue
• Leg, ankle, or foot swelling

Expert Opinions

Young emphasized the significant implications of the study, noting the well-established risk increase for cardiometabolic diseases, including obesity, diabetes, hypertension, stroke, and heart attacks due to environmental factors disrupting sleep and circadian rhythms.

He recommended reducing nighttime light exposure, suggesting blocking blue light wavelength as an alternative when reducing light exposure isn’t feasible. Young also proposed “resynchronizing clocks” by engaging in morning activities like light exposure, eating breakfast, and physical activities.

Reference: Jin Dai, Wen Dai, Yoriko Heianza, Lu Qi, (2026) Nighttime light exposure and cardiac structure and function, European Heart Journal. https://doi.org/10.1093/eurheartj/ehag563