IN DEFENSE OF SUNLIGHT

Star power.

“Get sun. Not too much. Go outside.” That message from science writer Jacobsen pays tribute to food writer Michael Pollan’s famous advice about eating: “Eat food. Not too much. Mostly plants.” In this well-written, thoroughly documented book, Jacobsen weaves personal anecdotes with decades of scientific research and experiments as well as interviews with scientists, indicating that regular exposure to natural sunlight can lead to increased brain activity and improved mood and cognition. Using sun exposure to help patients improve their health is a medical approach called heliotherapy, popular in the 1920s until the 1980s, when concerns about possible links between skin cancers and sun exposure made people avoid the sun and slather on SPF lotions, helping fund a $200-million-a-year industry. But most of those concerns have largely been disproven, Jacobsen says. Of the various types of skin cancers, “the common ones aren’t very deadly, and the deadly ones aren’t very common.” The amount of sunlight each of us needs is not a “one-size-fits-all” approach but should be considered for individual skin types—fair skin can benefit from lesser amounts of sunshine than darker skin, but the main message from researchers is “just don’t get burnt.” Sunscreen should offer broad-spectrum coverage (both UVB and UVA rays). SPF15 is probably sufficient for most people, and anything higher than SPF30 is blocking out vital Vitamin D. Skin, writes Jacobsen, is “the organ that set[s] the tone for the functioning of the entire body,” and sunlight helps skin do its job by stimulating a molecule known as POMC, which increases production of melanin, a skin-protecting antioxidant; initiates the production of cortisol, making you more alert; and delivers endorphins to the brain, improving both mood and cognition. For the best overall approach, the advice is simple: Get outside every day (morning light is best), let natural light into your home or workplace, and go as dark as possible when it’s time to sleep.

An engaging science-based “energy diet” that advocates for appropriate doses of sunshine.