It could be time to get heavier curtains in your bedroom. A new study has added to the growing evidence that sleeping in absolute darkness is beneficial – in fact vital to our health.
It all seems to have something to do with the production of melatonin – the hormone present in plants, animals and humans where it is released during the night to establish circadian rhythms.
In a paper published today, scientists say they have found that melatonin helps combat obesity and diabetes in rats. The study, published in the Journal of Pineal Research, confirms similar studies conducted by these researchers during the past three years.
They believe the benefits come from improved consumption of oxygen, the reduction of free-radicals and protection of the mitochondrial membrane.
The problem is, however, that the natural process of producing melatonin is interrupted by the exposure of artificial lighting during the night, which reduces the levels of endogenous melatonine—for instance, many people are in the habit of sleeping with their lamps, TVs or their computers switched on, or with the blinds drawn up.
“For all these reasons, it is important to try to sleep in absolute darkness, to avoid interference in the generation of melatonin,” says professor Ahmad Agil of the University of Granada, who led the study.
This appears to support other research.
In August, Cosmos reported on another study that suggested that greater production of melatonin improved the performance of breast cancer drug tamoxifen. That research compared the growth of breast cancer in rats kept in darkness overnight with rats given nightlights.
The cancers in rats given pitch-dark nights grew more slowly and tamoxifen dramatically shrank their tumours.
Read science facts, not fiction...
There’s never been a more important time to explain the facts, cherish evidence-based knowledge and to showcase the latest scientific, technological and engineering breakthroughs. Cosmos is published by The Royal Institution of Australia, a charity dedicated to connecting people with the world of science. Financial contributions, however big or small, help us provide access to trusted science information at a time when the world needs it most. Please support us by making a donation or purchasing a subscription today.