Tuesday, May 22, 2012

Sunlight: Boosts Mood and Strengthens Bones

In honor of the beautiful weather in Michigan, I am dedicating this week to talking about the sun. No, I won’t be talking like an astronomer... What good would the diameter of the sun be to you? Instead, I’ll be looking at the effects of the sun on our bodies, starting with the positive effects of sunlight on mood and diet today, the dangers of tanning on Wednesday and how to beat sunburns on Friday.

(Oh, and it’s 860,000 miles in diameter, by the way – over 110 times the size of Earth.)

Most people love the summer. We associate it with happy memories like swimming, hiking, going to beaches, vacations and so on. Poets and writers throughout the ages have used spring and summer as metaphors for youth, life and happiness, like William Carlos Williams, “In summer, the song sings itself.” Birds are chirping, flowers are blooming, and even if you’re having a better day, you can’t deny how pretty a blue sky looks.

But is our happiness owed to the calendar date, or something else?

Well, I tipped my hand in my first paragraph, but studies have shown that sunlight improves our mood. When you’re exposed to full-spectrum sunlight, you body produces serotonin, a feel-good brain chemical. This is the same chemical that anti-depressants regulate in order to maintain mood. 

So, that’s nifty. But what are the implications of these studies?

Well, just as spring and summer are metaphors for life, fall and winter and synonymous with death and drudgery. Like George Herbert said, “Every mile is two in winter.” Just as sunlight helps to boost mood, lack of sunlight depresses it. Seasonal Affective Disorder, a psychological dysfunction, has been noted in people during the winter, when the days are shorter and they get less sunlight. SAD (a clever acronym) can worsen depression, forcing many doctors to increase dosages of anti-depressants until spring rolls around.

Some therapists have tried to use phototherapy (treating patients with sunlamps) as a way to treat depression . And it works. Although light therapy doesn’t cure depression or SAD, it eases the symptoms.

VITAMIN D (I don’t have a song for this, sorry)

So sunshine helps mood. But it does more than that: sunlight is also a major source of vitamin D.

When I heard this as a kid, I was confused. How can vitamins fall from the sky? More importantly, how are vitamins getting into my body from the sky? Is it vitamin D radiation? Should I be worried about possible side-effects, like turning into the Hulk?

Well, no. Ultraviolet radiation, that lovely light-wave that causes suntans and sunburns, triggers vitamin D synthesis in the skin. In turn, the vitamin acts like a supervisor for the calcium in your body – it makes sure that the calcium gets to where it needs to be (your bones.) The vitamin also maintains consistent levels of calcium in your bloodstream. Without vitamin D, calcium gets lazy, causing rickets in kids and osteoporosis in adults.

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