The sun and our skin

Throughout human history, the Sun has been a source of reverence. Our Sun beams life-giving energy to Earth that nourishes the plant and animal kingdoms. Animals (including humans) eat both plants and as well as other plant-eating animals. We also absorb the ultraviolet (UV) spectrum to fuel internal production of Vitamin D- an essential nutrient required for life. On the other hand, UV can damage the collagen and elastin molecules that make up youthful skin turgor and UV can also inflict injury to the DNA in our cells, producing skin cancer. Our skin has evolved to embrace and protect this delicate relationship with the Sun by utilizing melanin, a remarkable molecule that functions as the body’s built-in UV protection.

The spectrum of human skin tones reflects the rich diversity of our ancestral distance from the equator. Every one of us, from pale white complexion to dark skin, has billions of melanin molecules within our skin, protecting us. Human ancestors further from the equator adapted to reduced sunlight levels by having less melanin. This adaptation allowed more UV penetration for life-essential Vitamin D metabolism. On the other hand, the constant intense sun exposure near the equator caused the adaptation of darker skin- with high levels of melanin- to protect against molecular damage. Problems in the melanin pathway lead to aesthetic skin problems such as complexion irregularity, sun spots, and melasma.

Our close relationship with the Sun will continue for as long as life exists on earth. As a physician, I encourage my patients to enjoy a life rich with copious outdoor activity. However, sun exposure need not injure or age us. Science has evolved. With a little help from proper skincare, all of us- regardless of skin type- can enjoy the healthy and radiant skin we deserve.
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