Sleeping with a Moderate Light Exposure May Harm Heart Health: Study

According to a new report from a Northwestern Medicine study, light exposure during nighttime sleep may harm heart health. Even moderate ambient lighting during nighttime sleep has affected cardiovascular function and increased insulin resistance the following morning.

It is known that light exposure during the daytime increases heart rate through the activation of the sympathetic nervous system. This kicks the heart into high gear and heightens alertness to keep you going throughout the day. However, this report shows a similar effect when exposure to light occurs at night.


The sympathetic nervous system takes charge during the day, and the parasympathetic is supposed to activate at night when it helps restore the entire body. But if there is exposure to light during the sleep cycle, the parasympathetic nervous system seems to continue.

Dr. Daniela Grimaldi explains, “Even though you are asleep, your autonomic nervous system is activated. That’s bad. Usually, your heart rate together with other cardiovascular parameters or lower at night and higher during the day.”

The investigators of this report concluded that moderate light exposure might cause the body to go into a higher alert state. In this state, heart rate increases, and the rate of how fast blood is conducted into the blood vessels for oxygenated blood flow is increased.

Insulin resistance was also found to occur the morning after people slept in a light room, leading to diabetes and obesity. Insulin resistance happens when the muscles, fat, and liver cells don’t respond well to insulin and can’t use glucose from the blood for energy. The pancreas then kicks in and makes more insulin, and over time, blood sugar will go up.

Many people are exposed to artificial light at night either from devices emitting light or from sources outside the home, particularly in large urban areas. Approximately 40% of people also admit to sleeping with a bedside lamp or television.

For people living in modern societies where exposure to nighttime light is increasingly widespread, this report should prove as a warning that it may be affecting their heart health.

Experts recommend turning all lights off during the night, including the TV. If a light is required, color is important. Amber or red light is less stimulating for the brain. They also recommend using blackout shades or eye masks for those who cannot control the outdoor light.

If you’re able to see things really well, your room is probably too light.

Get a Better Nighttime Sleep


Getting a good night’s sleep can help keep heart health on track. Sleep Sure Plus is a doctor-formulated supplement that can help to improve sleep quality and reduce anxiety. It is designed to help promote optimal sleep and restfulness using a variety of ingredients.

The most important ingredient found in Sleep Sure Plus is melatonin, a hormone essential for regulating the circadian rhythm. This hormone is typically released at night, making it easier to fall asleep.

Getting the proper vitamins and nutrients is essential for getting a quality night’s sleep. As this report outlines, poor sleep caused by the interference of light exposure can increase the risk for many types of illness and disease, including heart disease and diabetes.

Author Bio

Sarah began her interest in nutritional healing at an early age. After going through health problems and becoming frustrated with the conventional ways doctors wanted to treat her illness (which were not working), she took it upon herself to find alternative treatments. This led her to revolutionize her own diet to help her get healthier and tackle her health problems. She began treating her illness by living a more balanced lifestyle through healthy food choices, exercise and other alternative medicine such as meditation. This total positive lifestyle change led her to earn a diploma in Nutritional Therapy from Health Sciences Academy in London, England. Today, Sarah enjoys helping others by teaching healthy lifestyle changes through her personal consultations and with her regular contributions to the Doctors Health Press. Also, passionate about following her dreams in life, Sarah moved to France and lived in Paris for over 5 years where she earned a certification in beadwork and embroidery from Lesage (an atelier owned by Chanel). She then went on to be a familiar face sitting front row and reporting from Paris Fashion Week. Sarah continues to practice some of the cultural ways of life she learned while in Europe. They enjoy their food, and take the time to relax and enjoy many of life’s little moments. These are life lessons she is glad to have brought back home with her.


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