Why Keeping Lights on at Night is Bad For Your Health
Are you afraid of sleeping in the dark? Don’t be!
The dark may have frightened you as a child, but slumbering in a pitch-black room without a sliver of light coming through is a smart decision for your health.
In fact, research suggests that sleeping in a pitch-black room could lower your risk for cancer and even improve your metabolic health. Plus, animal studies suggest that sleeping in the dark without external sources of light helps with weight control.
Sleeping in the Dark Impacts a Hormone Called Melatonin
The benefits of sleeping in the dark have to do with its impact on melatonin, a hormone the pineal gland, a tiny gland in your brain produces. Melatonin is one of your body’s most potent antioxidant, a substance that counters oxidative stress. It also sets your body’s circadian rhythms, the timetable your body follows when it releases hormones and factors that affect your immune system, blood sugar control, sleep-wake cycle, mood, appetite hormones, fertility, digestive function, and more.
One of the signals for the pineal gland to release melatonin is the absence of light hitting the back of your eyes. Therefore, you produce more melatonin at night when light levels are lower and less melatonin during the day when the sun is shining and there’s plentiful light. In fact, melatonin release peaks at between 12:00 and 2:00 A.M. in the morning.
Unfortunately, even small amounts of light can shut down melatonin production. The downside of this is you don’t get the antioxidant benefits that melatonin offers and it disrupts your body’s natural circadian rhythms. Why is this a problem? Unbalanced circadian rhythms are linked with problems like insomnia, fatigue, immune system suppression, mental depression, and type 2-diabetes. Plus, a study shows that disruption in circadian rhythms can also lead to weight gain.
“A well spent day brings happy sleep” ~Leonardo daVinci
Can Sleeping in the Dark Lower Your Risk of Cancer?
Being a natural antioxidant, melatonin may give your body greater resistance to cancer. However, if you stay up late at night or sleep with the light on, you suppress melatonin and block melatonin’s protective benefits. In fact, some studies show that people who work night shifts where they’re exposed to light during the hours when they would normally be sleeping have a higher risk of some forms of cancer.
Experts believe the cancer risk may be explained by the fact that third-shift workers produce less melatonin because their eyes are exposed to light at night. It makes sense because light suppresses melatonin production.
In addition, research finds that women with breast cancer and men with prostate cancer have lower melatonin levels than those free of these diseases. In a lab setting, adding melatonin to breast cancer cells in a laboratory setting slows down their growth. With these benefits, it’s important to maximize your body’s ability to release melatonin.
What about sleep quality? Another study carried out by Brigham and Women’s University Medical Center in Boston found that women who slept at intervals, as some people who work rotating shifts do, experienced a slowing of their resting metabolic rate and a rise in blood glucose. Therefore, even irregular light exposure at night may harm your metabolic health and contribute to weight gain.
Is Melatonin Involved in Aging?
Could melatonin be the fountain of youth? It’s too early to say, but research shows it has anti-aging effects in mice. Also interesting is the fact that melatonin may affect the risk of getting certain types of cancer, especially breast cancer in women and prostate cancer in men.
No day is so bad it can’t be fixed with a nap. ~Carrie Snow
How might it do this? Melatonin may influence cancer risk in a number of ways — by its effects on hormones like estrogen or by beneficial effects on the immune system. Being a strong antioxidant, melatonin also helps prevent cell injury and damage to DNA, a cell’s genetic material.
Why Sleeping in the Dark is Good for Your Health
When you consider that exposing your eyes to light at night shuts down melatonin production, it’s easy to see why sleeping in the dark is so important for your immune system, to reduce the risk of cancer, and, possibly, to slow down the aging process. Even a tiny amount of light, during the hours when you should be asleep can reduce how much melatonin your pineal gland releases.
Tips for Maximizing Melatonin Production at Night
- Go to bed early. Melatonin production peaks between the hours of 12:00 A.M. and 2:00 A.M, assuming you don’t expose your eyes to light. Try to be in bed before melatonin production peaks, ideally before 10:00 P.M.
- Remove all sources of light from the room you sleep in. Even the light from an electronic clock can shut down melatonin. Close the blinds tight and cover any digital devices that put out light. You want your sleeping environment to be as free of light as possible.
- Keep electrical devices like computers away from your sleeping area. There’s some evidence that the electromagnetic fields they produce can reduce melatonin production.
- If you can’t remove all sources of light from your sleeping area, wear a light-blocking mask, also called a sleep mask, to cover your eyes and block light when you sleep.
- Avoid alcohol or caffeine at night so you can avoid trips to the bathroom where you might be exposed to light.
Should You Take a Melatonin Supplement?
As you age, the pineal gland in your brain produces less melatonin. This may explain why older people experience more insomnia since melatonin is important for regulating sleep. Melatonin supplements appear to be safe for short-term use but whether they’re safe long-term is unknown.
If you don’t like the idea of taking a melatonin supplement (affiliate), drink a glass of tart cherry juice with no added sugar before bedtime. Tart cherries increase melatonin naturally. Plus, they have natural anti-inflammatory properties. You can find tart cherry juice concentrate at some natural food and health food stores that you can dilute with water. Another alternative is to take tart cherry extract.
Take-Home Message
Sleep in darkness unless you’re at risk of falling. It’s better for your health!
References:
- Immunity & Ageing 2005, 2:17.
- ScienceDaily. com. “High Melatonin Content Can Help Delay Aging, Mouse Study Suggests”
- Cancer Epidemiol. Biomarkers Prev. 13 (6): 936–43.
- University of Maryland Medical Center. “Melatonin”
- Nutraingredients-USA.com. “Melatonin-rich tart cherries may improve sleep quality: RCT”
- Journal of the American Medical Association News. “Disrupting Body’s Biological Clock May Increase Risk of Weight Gain, Diabetes”
- WebMD. “Hormone Melatonin & Type 2 Diabetes May Be Linked”