I believe most of
us are accustomed to sleep in darkness. The real reason we want to
continue doing this has something to do with secretion of melatonin in
pineal gland during the middle of the night . Melatonin is a powerful
hormone that play various critical roles in anti-oxidant activities,
prevention of DNA damage, Immune system regulation and other health
promotional activities. As melatonin (also known as the hormone of
darkness) can only be secreted in darkness, it make sense go to bed in
pitch black condition for optimal secretion of melatonin.
Normally, the production of
melatonin by the pineal gland is inhibited by light and permitted by
darkness. For this reason melatonin has been called "the hormone of
darkness". The secretion of melatonin peaks in the middle of the night,
and gradually falls during the second half of the night. Until recent
history, humans in temperate climates were exposed to up to eighteen hours
of darkness in the winter. In this modern world, artificial lighting
typically reduces this to eight hours or less per day all year round. Even
low light levels inhibit melatonin production to some extent, but
over-illumination can create significant reduction in melatonin
production. Reduced melatonin production has been proposed as a likely
factor in the significantly higher cancer rates in night workers,[9] and
the effect of modern lighting practice on endogenous melatonin has been
proposed as a contributory factor to the larger overall incidence of some
cancers in the developed world. Wikipedia
If you are night workers and there is no way that you going to change
your job, go ahead and get a good night shade when you sleep at daytime to
at least squeeze some melatonin out of your gland though i'm not exactly sure
if this is really effective because the Melatonin secretion seem to be peak at
night (programmed biologically?).
