Are you afraid of the dark? If not, it might be time to invest in some blackout shades for your bedroom. New research shows a startling correlation between light pollution while you sleep, your overall feeling of wellbeing, and a larger waistline.

What is Light Pollution?

Yikes! That is scary…depression and a larger waistline? When it comes to light pollution, there are a few, simple steps you can follow to avoid such nasty outcomes. But before you jump too far ahead, first, we should define the term “light pollution.”

According to Verlyn Klinkenborg of National Geographic:

“Light pollution is largely the result of bad lighting design, which allows artificial light to shine outward and upward into the sky, where it’s not wanted, instead of focusing it downward, where it is. Ill-designed lighting washes out the darkness of night and radically alters the light levels—and light rhythms—to which many forms of life, including ourselves, have adapted. Wherever human light spills into the natural world, some aspect of life—migration, reproduction, feeding—is affected.”

Be it poor design, a lack of concern with light rhythms, or just plain disregard, the night sky is getting increasingly brighter. This modern day issue isn’t just annoying for those of us who prefer a blackened bedroom, it’s deleterious to our health and wellness.

Light Pollution Isn’t Just Depressing To Stargazers

Long-term exposure to artificial light during sleeping hours may play a role in today’s rising rates of depression in humans. In an Ohio State University study, researchers found that nightly, ongoing exposure to light can lead to depressive symptoms in rodents.

In their tests, they exposed hamsters to light at night for four weeks. Not only did this incite depressive behavior, but changes in the brain also resulted from 24/7 light exposure.

One protein, in particular, seems to explain how light at night leads to depression. Tumor necrosis factor (TNF) belongs to the cytokine family of proteins which go to work when the body is injured or has an infection. However, in their attempts to repair the body, they cause inflammation; when constant, this inflammation can be damaging.

A strong correlation exists between chronic inflammation and depression. When the subject was exposed to dim light during sleeping hours, TNF levels increased, inflammation increased, and depressive behaviors emerged. Fortunately, after only two weeks of returning to a typical light cycle, all negative outcomes- including physical changes to the brain- were fully reversed.

The Link Between Light Pollution and A Larger Waistline

In a survey of 113,000 women led by the Institute of Cancer Research, participants were asked to rate the amount of light in their bedrooms at night as:

  • Light enough to read
  • Light enough to see across the room, but not read
  • Light enough to see your hand in front of you, but not across the room
  • Too dark to see your hand or you wear a mask

Afterward, researchers compared their answers to several measures of obesity including BMI, waist circumference, and waist-to-hip ratio. They found a distinct correlation in women who reported that their bedrooms were “light enough to see across” and larger waistlines.

The idea of having a larger waistline might seem like an aesthetic concern, but, unfortunately, obesity is a major risk factor is diseases such as coronary heart disease, stroke, and cancer.

Wondering what you can do to reduce light pollution in your bedroom? Read our next article for some of our favorite tips and tricks.