BACKGROUND: Topical sunscreens provide a barrier that reduces the amount of harmful ultraviolet rays in sunlight from reaching the skin. Some clinical studies have found that antioxidant supplements, such as beta-carotene, enhance antioxidant levels in the skin and resistance to sunburn. Multiple antioxidants -- the so-called "antioxidant network" -- may provide still greater benefits.
RESEARCH: In an experiment, researchers supplemented human skin cells with various combinations of antioxidants, including vitamin E, vitamin C, beta- carotene, lycopene, and carnosic acid (an extract of the herb rosemary).
Treated and untreated human cells were then exposed to ultraviolet A rays. The researchers measured levels of metalloproteinase 1 mRNA and heme- oxygenase 1, both markers of skin damage from ultraviolet rays.
RESULTS: Combinations of antioxidants were more effective than individual compounds in reducing metalloproteinase 1 mRNA levels after exposure to ultraviolet rays. Lycopene and beta-carotene by themselves were not protective, and they even increased metalloproteinase 1 mRNA levels. However, a combination of these carotenoids and vitamin E completely protected against this type of ultraviolet damage. A combination of vitamins E and C and carnosic acid was also protective. However, none of the antioxidants protected against heme-oxygenase 1 damage.
IMPLICATIONS: This study suggests that combinations of antioxidants -- the antioxidant network -- were effective in minimizing an important marker of ultraviolet damage to skin. Consumption of such antioxidants may help skin better withstand ultraviolet rays. The researchers wrote, "In the future, combinations of natural compounds may be envisaged for effective photoprotection."
Offord EA, Gautier JC, Avanti O, et al., "Photoprotective potential of lycopene, beta-carotene, vitamin E, vitamin C, and carnosic acid in UVA- irradiated human skin fibroblasts." Free Radical Biology & Medicine, 2002; 32:1293-1303.
For the original abstract, visit: http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&li st_uids=12057767&dopt=Abstract