An observational study analyzed the effects of ambient light
on the mood and sleep of more than 400,000 people belonging to the British
biobank. The Biobank is a large-scale biomedical database and research resource
containing detailed medical and genetic information for half a million UK
taxpayers.
Participants were asked about their mood, what medications
they took when needed, and how much time they spent outdoors on a archetypal
summer and winter day. On average, participants reported spending two and a
half hours outdoors, with early risers reporting the longest time compared to
night owls.
Previous research has revealed that spending time in nature
and in nature has a number of health benefits, around of which may be related
to the fact that natural light is the most important ambient time signal for
circadian rhythms. of the body.
Rather, the lack of natural light may be a key contributor
to our recessions and sleep problems associated with depression, one of the
leading causes of disability worldwide.
"Humans have evolved in an environment that clearly
distinguishes between day and night, but our modern environment has blurred
that distinction," the group explains in their article.
Today, people apply "most of their waking hours under
intermediate artificial lighting due to less exposure to sunlight and
relatively bright night light." This situation can cause sleep
disturbances, since light affects melatonin, a hormone that promotes sleep by
suppressing it.
In an earlier study by the same group of scientists, nearly
half of the homes in the Melbourne study were found to be bright enough to
suppress melatonin by 50%, although this is certainly not the case. Artificial
light affects everyone equally.
In this latest study, Sean Kane of Monash University in
Melbourne and his team wanted to test the relationship between hours of the day
outdoors and mood, sleep quality, and overall health, a factor less studied
than the effects of night light.
The analysis found that getting more light anytime between
sunrise and sunset was associated with better mood and better-quality sleep, as
well as a subordinate risk of depression and less use of downers.
Each additional hour of normal light was also associated
with lower chances of depression throughout life, less use of antidepressants,
and greater happiness. And those who reported being in a better mood and
sleeping with more ambient light tended to do so again in the second survey, an
average of four years later.
Results in the sun are somewhat expected based on what we
know about light, nature, sleep patterns, and mood, but what's encouraging is
that such a large study demonstrates the effect of spending more time outdoors.
. Of course, this is an observational study in which participants must answer
about their daily and health-related habits, so the answers they give may
differ from what they actually do.
