Here Comes the Sun...And Things Are Looking Brighter

Spring is coming and so is the sun. Or more precisely, a Daylight Savings Time extra hour of sunlight each day. To mark the moment, the Washington Post asked three experts to detail the benefits on our body and soul.

First on the list, according to Jamie Zeitzer, co-director of the Stanford Center for Sleep and Circadian Sciences is sunlight’s ability to regulate the body’s circadian rhythm, the internal cock that governs all kind of goodies such as sleep, appetite, digestion, immunity, hormone production, and heart and muscle function. To the best way to maximize the effect? Stand (or sit) in sunlight for about 20 minutes right after waking.

This cancels the work of the sleep hormone melatonin while powering the wake-up hormones histamine and cortisol. In addition, getting more light during the day may help offset the negative anti sleep effects of artificial light such as the glow from a computer or smart phone at night.

Exposure to sunlight also affects how the body breaks down glucose, the natural sugar fuel in food, says Tobias Eckle, a professor of anesthesiology at the University of Colorado. Anschutz research projects focus on the health effects of daylight exposure which he and his colleagues believe may even effectively improve glucose control for people with Type 2 diabetes. Their backup is one small study published two months ago in the in the January 6 edition of the journal Cell Metabolism in which researchers split 13 Type 2 sufferers into two groups, the first sitting close to a sun-lit window the second working inside, under artificial light. Four- and one-half days later, at the end of the trial, the window-sitters had experienced longer periods of healthful blood sugar levels.

They may also have been happier because, as Zeitzer notes, sunlight can be a powerful mood enhancer: “You go outside and you feel better.” Exactly why remains a mystery, but the possibility is that sunlight, like the SSRI meds used to treat depression, helps regulate the release of serotonin and dopamine. If so, this “helps improve emotional stability,” says neurologist Alon Avidan, the director of the UCLA Sleep Disorders Center. In fact, this is why light is increasingly used as a treatment for depression.

Sunshine is also nutritious: It enhances the absorption of vitamin D, the multi-function nutrient that combines with calcium to promote strong bones, plus muscle density, nerve activity and immunity. For optimal D levels, Avidan advises aiming for 5 to 30 minutes of sun daily, or at the very least twice a week.

Finally, as with all good things few problem lurk in the background, here the common one being its ultraviolet UVA and UVB rays, strongest between 10 AM and 4 PM, which age skin and may trigger skin cancer. One accepted remedy is sunscreen with a Screen Protective Factor (SPF) 15 or higher considered labeled “broad spectrum” because it blocks both UVA and UVB rays. Protective clothing such as wide-brimmed hats, long pants and long-sleeved tops are, yes, protective. So are sun glasses labeled “UV absorption up to 400 nm” or “Meets ANSI UV Requirements” which the American Cancer Society says block at least 99% of UV rays; glasses labeled “cosmetic” block about 70% of UV rays. Slitting under a tree, umbrellas or shades during the mid-day hours when the ultraviolent rays are strongest is also strategic.