From TIME · Veronique Greenwood · · 1m 30s
Your bedroom light may be straining your heart
A new study scanned the hearts of people who sleep with the lights on, and found walls that had already thickened.
In brief
A new study scanned the hearts of people who sleep with the lights on, and found walls that had already thickened. Make the bedroom as dark as you can. Blackout curtains, hall light off, eye mask on, and your heart may thank you for it. Originally reported by TIME.
Night used to be dark
For almost all of human history, sunset meant total blackness. Now a hall light, a streetlamp, or a TV two rooms away keeps most of us in a permanent dim glow.
“For most of human history, night has been dark. Very, very dark”
A pattern keeps showing up
Light at night already tracks with higher rates of diabetes, obesity, and hypertension. Last year researchers tied it to heart failure and other cardiovascular problems over a decade.
Now the heart itself
A team publishing in the European Heart Journal on September 9 reports that people exposed to light at night have structural changes in their hearts, signs the organ is working harder than it should.
Sensors, not memories
Researchers used UK Biobank fitness monitors with built-in light sensors, worn for a week. Most earlier studies just asked people how bright their bedrooms were.
“That's very unique, because most previous studies have used self-reported light exposure”
Three candles is enough
People sleeping under at least 3 lux, roughly three candles held three feet away, had thicker heart walls and weaker pumping on MRI. Not disease yet, but what comes before it.
Just turn it off
The link is correlational, and nobody knows if the culprit was a tablet, a TV, or the hallway. Still, darkness is free: blackout curtains, lights off, an eye mask.
“Draw an eye mask over your eyes, and know that it could be helping your heart.”
The essence
Make the bedroom as dark as you can. Blackout curtains, hall light off, eye mask on, and your heart may thank you for it.
