What's in your sunscreen?
Updated: Dec 18, 2020
As delightful as it feels to be outside on a Minnesota summer day, the life-giving rays of the sun can exact a price on our skin. In fact, even a “healthy” suntan is the result of skin damage caused by sunlight. Excessive sun exposure even without burning can cause wrinkling, hyperpigmentation, leathery skin, and skin cancer. The sun’s ultraviolet (UV) radiation can be either UVA (long-wave) or UVB (short-wave); UVA rays are less intense but penetrate more deeply into the skin and can go through glass, and UVB rays are more intense (this is what causes sunburn) and damage more superficial skin layers. If you are going to be outside away from the shade, it’s important for both your immediate and your long-term health to use a sunscreen as well as other protective measures.
Though many people use sunscreen and sunblock interchangeably, sunscreen traditionally refers to chemical sunscreen while sunblock (though misleading, as nothing blocks sun rays completely) refers to physical sunscreen. Chemical sunscreens work by absorbing into the skin and filtering UV rays. While these were more popular in the past as they are generally transparent and don’t leave a greasy coating, they can be problematic; since they are designed to be absorbed, any potentially harmful chemicals they contain are also absorbed. The most worrisome are oxybenzone, which can cause skin irritation as well as endocrine and hormone disruption and is linked to endometriosis; octinoxate, which affects thyroid and reproductive hormone levels and produces free radicals; and retinal palmitate, a form of Vitamin A that can break down and produce free radicals when exposed to UV rays, potentially encouraging tumor growth and speeding malignant cell development.
Physical sunscreens—traditionally zinc oxide and titanium oxide—block or reflect sunlight when applied on the surface of the skin. While older formulas were heavy, greasy, and left a white film, advances in technology have produced sunscreen without these effects. While there is some concern regarding nanoparticles of zinc and titanium oxide and their potential absorption into the skin, most experts feel that physical sunscreens are still the safer option—particularly when considering skin cancer risks. Additionally, some companies are now including non-nanoparticle zinc oxide in their formulas, including both brands carried at Harmony Co-op—Goddess Garden and Badger, both of which made the Environmental Working Group’s lists for best beach sunscreen and best kids’ sunscreen this year.
While there are sunscreens on the market that are SPF 60, 75, even SPF 100—bigger is not always better. SPFs above 50 do not proportionally increase their protection. SPF 30 blocks 97% of sun rays; SPF 50 blocks 98%. Higher numbers are more expensive without much more return. Experts recommend a broad-spectrum sunscreen (blocking both UVA and UVB) with a minimum SPF of 15 and a maximum of 50. Sunscreen should be reapplied a minimum of every two hours or after swimming, and about one ounce (a shot glass worth) should cover your exposed skin.
Whatever sunscreen you choose, it should not be your first line of defense. To help avoid sunburn and sun damage, the Skin Cancer Foundation recommends limiting your sun exposure during the time of day when the sun’s rays are strongest (between 10 AM-4 PM), wearing loose-fitting and tightly-woven clothing, wearing a hat and sunglasses (your eyes can also be affected by UV radiation, causing cataracts) and keeping to the shade. You’ll be able to get out on the lake or under the sky without ruining your fun—or your future health!