Let there be light!

Today, for the first time this year, Ameba and I played tennis. And it was fantastic - we were outside, on the courts, in T-shirts, the sky was blue and the sun was out - and even warm (our tennis is coming along too!)


Which brings me to today's fact: the sun makes people happier. Fact. 

Working it's magic

According to howstuffworks.com the following is what happens when the sun shines:

One area where humans may not be able to escape the sun's biological effects is on their moods. It all comes down to a complex relationship among sunlight, melatonin and serotonin that we're only just starting to understand.

Melatonin is a hormone that controls sleep, and serotonin in a neurotransmitter that is tied to states of wakefulness and being in a "good mood." Serotonin is the chemical targeted by a class of anti-depressants called SSRIs, which keep higher levels of serotonin in the bloodstream to help elevate mood.

The web connecting sunlight, melatonin and serotonin goes something like this: When the sun comes up again, and sunlight hits the optic nerve, some of that light is sent to the gland in the brain in charge of melatonin. In response, melatonin secretion decreases. When the sun goes down, the body increases its secretion of melatonin.

At the same time, when the body perceives sunlight, serotonin levels increase. And the more sunlight the human body is exposed to, the more serotonin the brain produces [source: ScienceBlog]. So in effect, melatonin and serotonin have an inverse-proportional relationship that is guided by the body's perception of sunlight. The overall effect is "downtime" at night and "uptime" during the day.

There's another factor involved in sunlight's affect on mood, though: vitamin D. The body actually creates its supply of vitamin D from the sun's ultraviolet rays hitting the skin, and high levels of vitamin help the body maintain high levels of serotonin [source: Collinge].

Guess there were quite a few happy people in London today :)

Lucky