What your Butt Can Tell You About Your Skin Health, According to this Expert

Wondering if you’re doing enough to protect your skin? Well, your butt is a good barometer.

A dermatologist and assistant clinical professor from Mount Sinai Hospital, Dr. Diane Madfes, spoke to Science of Us about the importance of proper sunscreen use and how that affects your skin. “A good way to reassure yourself is to look at areas that are photoprotected by clothes, i.e. the buttocks,” she says. “The skin in this area is smoother, tighter, with better elasticity.”

Think about it: The skin on your behind is way more supple and (most likely) untouched by the sun—which means that, if its texture is a far cry from what’s going on up top, you might want to reach for the nearest tube of SPF 30 and start lathering up the rest of your body, pronto.

Dr. Madfes goes on to explain the exact science behind sun damage. One major problem is that it suppresses your immune system, which allows skin cancer to grow. Another culprit behind making your sun-exposed skin not as soft as your rump are free radicals—they actually kill cells and activate enzymes that break down oh-so-precious collagen and elastin (which keeps skin looking youthful).

In other words, if you wear sunscreen every day, you’ll have fewer sun spots, fine-lines, and wrinkles, less sun damage, and you’ll be at a lower risk for skin cancer—no ifs, ands, or butts (wah wah) about it.

“If you do protect when you’re young,” Dr. Madfes tells Science of Us, “you’ll have it for your lifetime.” Her biggest tip? Put sunblock on after you brush your teeth, so it becomes routine.