Rowan Jacobsen’s In Defense of Sunlight (Scribner, 2026) makes the mainstream case that our culture’s fear of the sun has gone too far, and its most memorable moment comes courtesy of skin cancer specialist Rachel Neale, who advocates for short, frequent sun exposures with as much skin bared as possible. The logic is straightforward: maximizing the skin surface area exposed to sunlight is the most efficient way to trigger your body’s natural vitamin D production. Jacobsen runs with it: “Ten minutes of naked cartwheels in the backyard might not be a terrible idea.” It’s a joke, but only barely. The science behind it is real, reviewed this month in Nature, and backed by the kind of expert voices that tend to move the needle in public conversation.

Jacobsen doesn’t let the sunscreen industry off easy. Early sun creams blocked UVB — the rays behind sunburn — while allowing UVA straight through. Users felt protected, stayed out longer, and may have inadvertently increased their melanoma risk. Broad-spectrum formulas didn’t become standard until the 1990s. Even now, photobiologist Brian Diffey and other scientists say the evidence that sunscreen effectively reduces melanoma rates remains thin. Genetics, diet, skin type, and childhood burns are all significant factors. The takeaway isn’t anti-sunscreen — it’s that the “just wear more SPF” message has been oversimplified for decades, and the science is messier and more nuanced than public health campaigns have let on.

Jacobsen also cites a study of lifeguards tracked across a full summer that found by season’s end, their skin was enriched with beneficial microorganisms — ones that produce compounds capable of killing cancer cells without harming healthy tissue. Regular sun exposure, he argues, may help cultivate a living biological defense system right on the surface of your skin. On vitamin D, sunshine produces it in the form of a hormone that actively helps calcium get into bones — a different and arguably superior process to supplementation. Skin cancer specialist Rachel Neale points to the quiet return of rickets among indoor-dwelling children as the canary in the coal mine.

Jacobsen writes that without solar energy, we’d be “lumps of mud animated by light.” That’s a useful reframe for a culture that has spent decades treating the sun as purely a threat to be managed. Harvard neuroscientist Rami Burstein has found that green wavelengths relieve migraines. Forest-bathing traditions in Japan have long recognized the restorative power of natural light. The professional tanning industry has been on the right side of this conversation for a long time. Books like this one help bring the rest of the world along.

Click here to read more about the book from Nature.