“Wrinkling, freckles, skin thinning — everything we associate with aging is really sun damage, which is essentially DNA damage,” explains Moy. After someone goes tanning, you can measure DNA damage by testing the amount of toxins excreted by their urine.” When you’re 20, DNA repair enzymes in your skin are doing their job, but these enzyme levels drop as you get older. Moy suggests supplementing your body’s own supply with serums and creams fortified with DNA repair enzymes from natural plant sources like plankton.”