The Sun Emits Two Types of Rays
UVA rays, or aging rays, cause wrinkles and age spots. UVB rays, or burning rays, cause sunburn. But both of them can lead to skin cancer. Even the World Health Organization has declared UV radiation from the sun a known carcinogen.
Skin Cancer is the #1 Form of Cancer in the United States
And UV radiation from the sun is the #1 cause of skin cancer. (Remember: Sunlight in the winter has the same effect on your skin as sunlight in the summer!) Regular sun exposure mainly causes basal and squamous cell skin cancers, which are highly curable, while frequent severe sunburns can cause melanoma, the more deadly form of the disease. Scheduling an annual skin screening with a board certified dermatologist is a great way to catch these early.
SPF Protects From Photoaging
Exposure to the suns rays causes damage to the collagen, elastin, and cells in your skinthe stuff that, when broken down, leads to signs of aging like dark spots, fine lines, and textural changes. Broad spectrum SPF works by blocking UVA and UVB rays so that they cant reach the deeper layers of your skin. And though melanin-rich skin has some natural sun protection (up to SPF 13), lack of additional sunscreen coverage will lead to damage (SPF 30 is recommended).
SPF Can Reverse the Signs of Aging
You might want to sit down for this. A study in Dermatologic Surgery showed that using SPF 30 on your face for as little as 12 weeks may actually improve skin texture, clarity, and pigmentation. Its never too late, folks.
A Higher SPF Number Is Not Always Better
Dont fall into the trap of trusting SPF 100 (aka thinking you can stay in the sun all day without reapplying). In reality, SPF 30-50 blocks 98% of the suns rays. At best, anything higher makes a negligible difference, and at worst, it can provide a false sense of security. As a rule of thumb, always reapply SPF every two hours (aim to use a shot glass full to cover your whole body), or right after swimming.