Protecting Skin from the Inside Out
Jaclyn Chasse, ND
The sun is a funny thing — we certainly have a dependence on it, for light, for heat, for plants, for life!
We acknowledge its importance for stimulating production of vitamin D, which, like chlorophyll, is required for our own life and health. Yet, we also vilify the sun. We recognize that overexposure can be harmful, leading to uncomfortable burns and over time, increasing risk for skin cancers. Both melanoma and nonmelanoma skin cancer have ultraviolet (UV) exposure as a major risk factor, as both UVA and UVB radiation generate free radicals and can induce DNA, protein, and lipid damage.
Topical skin protection has been the way we’ve primarily dealt with the sun’s dangers. We’ve nurtured a dependence on toxic UVA and UVB protectants, and we slather our skin with these ingredients to prevent the short and long-term effects of a day on the sunny beach. But in addition to the interest in healthier and more spreadable topical skin protection (thank you, natural sunscreens!) there’s also been an increasing interest in the use of nutrients orally to protect the skin from sun damage.
The question is, does it work?
Innately, our body has mechanisms to combat free radical damage. Within the skin, we leverage enzymes such as superoxide dismutase and glutathione peroxidase, as well as non-enzymatic substances like vitamin C and E, to combat free-radical damage and protect the skin from cellular change. A review in the Journal of Skin Cancer summarized research on both oral antioxidant supplements as well as dietary intake of antioxidants from whole foods.
Vitamin C, beta-carotene, and vitamin E have been shown to protect hairless mice from developing tumors when exposed to UV light. A later study showed similar benefit from a mixture of vitamin C, selenium, green tea extract, and other naturally occurring antioxidants.
In human cells, vitamin C has been shown to increase the rate of DNA repair. Both vitamin C and E have shown photoprotective properties in human fibroblasts exposed to UVA light. Astaxanthin has been the subject of a few studies looking at UV protection, but has failed to show benefit. One study, published in 2014, gave adults with moderate photoaging a supplement containing 3 grams of collagen and 2 milligrams of astaxanthin daily. They exposed the subjects to ultraviolet light and the supplements or placebo for 12 weeks. The treatment group did show improvements in skin elasticity and transepidermal water loss (hydration), but there was no significant difference between UV-induced DNA damage between the treatment and placebo groups. Unfortunately, no in-vivo studies have successfully shown that oral intake of antioxidants can prevent skin damage or skin cancer in humans.
When prepping for sun exposure, adequate levels of vitamin D is a must. Additionally, antioxidants like astaxanthin, rutin, and hesperidin theoretically could be useful. Yet, because this has not been borne out in research, it’s best to consider these therapies in addition to, and not a substitution for, topical sunscreens or even just the shade of a palm tree.
 Yoon HS, Cho HH, Cho S, Lee SR, Shin MH, Chung JH. Supplementing with dietary astaxanthin combined with collagen hydrolysate improves facial elasticity and decreases matrix metalloproteinase-1 and -12 expression: a comparative study with placebo. J Med Food 2014 Jul;17(7):810-6.