To many of us, tan skin indicates a healthy, out-doorsy lifestyle. However, it doesn’t necessarily indicate healthy skin. In fact, there is probably no other single factor as destructive to the long-term strength and youthfulness of skin than the sun.

Although the most immediate effects of sun-damage are endured by the surface epidermal layer of our skin in the form of sunburns and drying, over time, exposure to UV radiation can penetrate deep into the underlying dermis and negatively effect the collagen structures within (a process called photoaging). This results in an eventual reduction in skin elasticity and the development of wrinkles. In addition, the alteration of these collagen structures can weaken the tiny blood vessels that are supported within them, making the vessels more likely to rupture and lead to discoloration as well as decreased circulation.

The truth is that as much as 90 percent of the wrinkles, brown spots, and sagging skin that we usually think of as signs of aging can be attributed to sun damage, this according to the the American Skin Association, a national organization for education on skin health. What’s worse, skin cancer is now the most common cancer, striking more than 800,000 annually in the U.S.

Which is not to say that panic is in order. While these dangers are real and should be taken seriously, diligent use of sunscreen as well as a daily moisturizer — especially one enhanced with antioxidants — capable of replenishing essential oils lost to the sun, can go a long way towards helping skin withstand many of the external causes of aging.