Make room for Some Darkness.

Interesting article. It may be beneficial to ensure we have some darkness during our daily lives. Some have to much light, for instance while in hospital or the aged in care homes.. As for the young needing sleep we all also may need some darkness..



Is artificial lighting making us sick? New evidence in mice

Along with eating right and exercising, people should consider adding another healthy habit to their list: turning out the lights. That's according to a new study reported in the Cell Press journal Current Biology on July 14 showing many negative health consequences for mice kept under conditions of constant light for a period of months.

"Our study shows that the environmental light-dark cycle is important for health," says Johanna Meijer of Leiden University Medical Center in the Netherlands. "We showed that the absence of environmental rhythms leads to severe disruption of a wide variety of health parameters." Those parameters included pro-inflammatory activation of the immune system, muscle loss, and early signs of osteoporosis. The researchers say that the observed physiological changes were all indicative of "frailty" as is typically seen in people or animals as they age. But there was some more encouraging news, too. "The good news is that we subsequently showed that these negative effects on health are reversible when the environmental light-dark cycle is restored," Meijer says.

medicalxpress.com...

Light at night is bad for your health, and exposure to blue light emitted by electronics and energy-efficient lightbulbs may be especially so. Until the advent of artificial lighting, the sun was the major source of lighting, and people spent their evenings in (relative) darkness. Now, in much of the world, evenings are illuminated, and we take our easy access to all those lumens pretty much for granted. But we may be paying a price for basking in all that light. At night, light throws the body's biological clock—the circadian rhythm—out of whack. Sleep suffers. Worse, research shows that it may contribute to the causation of cancer, diabetes, heart disease, and obesity. But not all colors of light have the same effect. Blue wavelengths—which are beneficial during daylight hours because they boost attention, reaction times, and mood—seem to be the most disruptive at night. And the proliferation of electronics with screens, as well as energy-efficient lighting, is increasing our exposure to blue wavelengths, especially after sundown.

Study after study has linked working the night shift and exposure to light at night to several types of cancer (breast, prostate), diabetes, heart disease, and obesity. It's not exactly clear why nighttime light exposure seems to be so bad for us. But we do know that exposure to light suppresses the secretion of melatonin, a hormone that influences circadian rhythms, and there's some experimental evidence (it's very preliminary) that lower melatonin levels might explain the association with cancer. A Harvard study shed a little bit of light on the possible connection to diabetes and possibly obesity. The researchers put 10 people on a schedule that gradually shifted the timing of their circadian rhythms. Their blood sugar levels increased, throwing them into a prediabetic state, and levels of leptin, a hormone that leaves people feeling full after a meal, went down. Even dim light can interfere with a person's circadian rhythm and melatonin secretion. A mere eight lux—a level of brightness exceeded by most table lamps and about twice that of a night light—has an effect, notes Stephen Lockley, a Harvard sleep researcher. Light at night is part of the reason so many people don't get enough sleep, says Lockley, and researchers have linked short sleep to increased risk for depression, as well as diabetes and cardiovascular problems.

www.health.harvard.edu...

a reply to: skywatcher44

That's according to a new study reported in the Cell Press journal Current Biology on July 14 showing many negative health consequences for mice kept under conditions of constant light for a period of months.

New study light is unhealthy?

Tell that to the torturers. They been doing it to break people ever since electric light was invented.

a reply to: skywatcher44

Spent 20yrs midnight Univ. Hosp. Go outside after 16 hr dbls...and wonder what that beautiful yellow thing is in the sky?

All the florescent lighting and hospital dull greys and tans really messed with me. And it screwed with my body's circadian rhythm for a long time....

This makes sense and I find it interesting that laws were passed to insure any new building or remodel of kitchen requires fluorescent lighting....?
Most folks agree in the complaining of fluoresant lights, I know they make me feel out of sorts.
There are energy efficient bulbs, in'm sure, they have a spiral shape and a Varity of hues.
We do need to turn out lights so our brains can produce meltitonin.
Thank you OP for all this research.

a reply to: skywatcher44

Honestly I'm not too surprised. We have a natural circadian rhythm that needs to be maintained, but the way our society currently functions is not conducive or supportive of this. Anyone who has worked a graveyard shift for a few months or so knows this better than most.

It's called "Light Pollution"

Def: brightening of the night sky caused by street lights and other man-made sources, which has a disruptive effect on natural cycles and inhibits the observation of stars and planets.

They've done some interesting research on the effects of light pollution and it's implication regarding prostate and breast cancer. As our current society is more go-go-go than ever, we are actually getting the least amount of voluntary sleep now than we ever have in recorded history. Settlement days were closer to 10-12 hours per day, whereas now the average person is out for 5-7 hours. I say this after being up all day and looking at a computer screen... I guess knowledge isn't always power.

Oh, I agree. When I was in the hospital, I could barely sleep at all. I'm so grateful to the help they gave me, but I couldn't help feeling I would have recovered faster if I had been able to get a good night's sleep.