“I personally enjoy my life,” said Keren, “but I use products on my skin which stop these free radicals” (free radicals can include UV rays and cigarette smoke if you’re around smokers). Vitamin C is a good shield and when she’s outside in summertime, Keren tops up her sunscreen every two hours. If you’re spending periods outside in the winter (even just exercising for an hour or heading out on a walk), sunscreen is also a great shout, as UV rays can penetrate the thickest of clouds.