A new Tulane University study is raising concerns about a common bedroom habit: sleeping with a light on. The research linked nighttime light exposure to a higher risk of cardiovascular disease, adding potential heart consequences to worries about disrupted sleep.

Researchers reported that exposure to more than 3 lux of light, approximately the brightness of moonlight, was associated with increased risks of heart failure, atrial fibrillation, heart attack, stroke and cardiovascular death. Atrial fibrillation is an irregular and often very rapid heart rhythm.

Erin Palinski-Wade, a New Jersey based nutritionist and author of "The Sleepdemic Solution," confirmed that household surroundings and ambient neighborhood conditions can directly interfere with restfulness. Experts who spoke with Fox News Digital detailed how bedroom light can affect sleep and health.

Sleep is partially controlled by the circadian rhythm, the brain’s internal 24 hour clock that regulates sleep and wakefulness, according to sleep expert and neuroscientist Chelsie Rohrscheib, Ph.D. Light entering the eyes strongly influences that rhythm.

"The circadian rhythm is strongly influenced by light entering the eyes – light exposure signals the brain to suppress melatonin production, a hormone that helps regulate the timing of sleep, while low light levels signal the brain to produce more melatonin," Rohrscheib told Fox News Digital.

As melatonin rises during the evening, it helps prepare the brain and body for sleep. Light pollution from bedroom sources can fool the brain into producing less melatonin, negatively affecting sleep quality.

Rohrscheib warned that consistent light exposure can chronically reduce overall sleep quality. Sleep supports body and brain restoration, hormone release, immune system function, memory consolidation, brain waste clearance and metabolic regulation.

When sleep remains poor, those processes do not function optimally, she said. That can elevate the risk of chronic conditions including hypertension, cardiovascular disease, stroke, type 2 diabetes, obesity, neurodegenerative diseases, certain cancers and mood disorders.

Rohrscheib also cited a 2022 Northwestern Medicine study that examined one night of sleep with moderate light exposure measuring 100 lux. That exposure disrupted glucose regulation while increasing heart rate and sympathetic nervous system activity, as reflected by reduced heart rate variability.

Sleep researcher Ashley Curtis, Ph.D., an assistant professor at the University of South Florida College of Nursing, said sleep impairment is also linked to increased mortality risk. She noted that emerging evidence suggests sleep disruption may affect the gut microbiome, with possible implications spanning digestion and immunity.

Certain people may be more sensitive to nighttime light, according to the experts. Alex Dimitriu, M.D., a double board certified sleep medicine doctor and founder of Menlo Park Psychiatry & Sleep Medicine, identified shift workers, children, older adults and people with insomnia or mood disorders as particularly vulnerable.

Curtis said older adults often become less sensitive to light, meaning bright or short wavelength light has a weaker effect on melatonin suppression than it does in younger people. However, older adults also have a higher baseline prevalence of sleep disruption, which can affect the circadian system in both directions.

Some evidence also suggests bright light has a more pronounced effect on melatonin suppression in men, Curtis noted. For people with insomnia, bright light before bedtime can worsen existing sleep disruption by further interfering with the biological circadian rhythm.

Blue wavelength light from televisions and phones is the most disruptive because people’s retinas are most sensitive to it, according to Dimitriu. This light also suppresses melatonin to the greatest degree.

"Dim, warm, red-toned night lights cause far less circadian impact – these are natural sunset colors one would see in the evenings," Dimitriu told Fox News Digital. Curtis agreed that dimmer, warmer light with a longer wavelength has less impact on melatonin production.

Curtis said research indicates that even when dim light initially affects melatonin, the body has time to recover. As a result, dim light does not disrupt sleep to the same degree as brighter light.

The experts recommended turning off harsh overhead lighting one to two hours before bed and using dimmer bulbs that produce orange, amber or red light. They also advised stopping computer and phone use at least one hour before bedtime to eliminate brain stimulation.

Layered window treatments can soften harsh, bright street lighting that enters the bedroom. A face mask can provide another barrier against light pollution and help protect sleep quality, even when creating a completely dark room is not possible.