Is Blue Light Bad for Your Heart?

Q: Every night I fall asleep with the TV on. My daughter says I should turn it off, because “blue light” is bad for my heart. Is this true?

A: Countless teens and adults are exposed to blue light at night from TVs, computers, iPads and cell phones in their bedrooms. These and other electronic devices aren’t dangerous in and of themselves. But researchers have discovered that they interrupt sleep and prevent the deep, restful sleep we need to be healthy.

Sleep that’s fragmented has been shown to increase inflammation and promote the early stages of atherosclerosis. People who awaken frequently at night are at increased risk of developing atrial fibrillation.

More recently, exposure to artificial light while sleeping was shown to correlate with a 17% increased risk of gaining 11 pounds and a 33% risk of obesity in women. Blue light, as well as white light from nightlights and lamps, had the same impact.

Although it’s impossible to prove that light exposure directly causes weight gain, other studies have shown that interrupted sleep leads to sleep deprivation.

When you’re sleep deprived, you feel the need to eat carbohydrates for energy. This likely explains the connection to weight gain, as well as to increased risk of developing developing metabolic syndrome and type 2 diabetes.

Heed your daughter’s advice and turn off the TV. It may take you a few nights to get used to a silent room, but when you do, you’ll sleep more soundly and, hopefully, stay healthy.

— Cardiologist Leslie Cho, MD