Eat for Beauty

Marjet D. Heitzer, Ph.D. The Plateau-proof Diet Foundation http://www.plateauproofdiet.com Email: info@plateauproofdiet.com Consuming a diet rich in beneficial nutrients such as vitamins and minerals results in many welcomed side effects such as weight loss and improved health not to mention enhanced beauty. It is important to state here that this column is concerned with the effects of nutrients derived from certain foods (not supplements) on your overall appearance. One of the many benefits of eating more fruits and vegetables may include reduced wrinkle formation, leading to younger looking skin. The definition of a wrinkle is: a small ridge, prominence, or furrow formed by the shrinking or contraction of any smooth substance. Of course, by the shear extent of creams that exist to combat the signs of aging (i.e. wrinkles), no reader needs to be reminded of the detailed definition. Although many of us are too familiar with the definition of a wrinkle, the reasons why we get them may not be clear. During the aging process, fat as well as collagen and elastin (matrix proteins responsible for the shape of organs) are lost in the skin. To combat wrinkle formation, many topical creams either replace the lost collagen and elastin or relax skin muscles, resulting in a smoother appearance. Sun damage by ultraviolet radiation (UVA) is one of the leading causes of premature aging of the skin. UVA induces premature aging by generating reactive oxygen species (ROS), thereby increasing oxidative stress in the skin. ROS induced by UVA, damages lipid, DNA, and proteins located within skin cells (1). Furthermore, UVA induces gene expression of certain enzymes, matrix metalloproteinases, which break down the support matrix, collagen and elastin, found in skin, possibly leading to wrinkle formation (1). For this reason, many marketing ads for wrinkle creams include key words such as free radical, collagen/elastin booster, and antioxidants. Beta-carotene is a member of the carotenoid family (the bright red, yellow, and orange pigments of fruit and vegetables) that is found in foods such as carrots and green, leafy vegetables. It is an antioxidant that is a potent ROS scavenger (2). Because beta-carotene quenches ROS, they can no long damage skin lipids, proteins, and DNA. Furthermore, beta-carotene represses UVA-induced matrix metalloproteinase expression, making it one of the few oral skin protectants that fight against premature aging. Along with directly combating premature aging by removing ROS, beta-carotene may indirectly affect wrinkle formation by increasing retinoic acid production in the skin. Beta-carotene is required for retinoic acid production which induces skin cell proliferation, perhaps leading to a thickening of the skin. In turn, a thicker skin layer may result in a smoother appearance of the surface of the skin. Because beta-carotene accumulates in the epidermis of the skin by ingestion, it was tested and confirmed to aid in protecting the skin from UVA-induced premature aging (3). Furthermore, the levels of beta-carotene obtained from a diet rich in fruits and vegetables were sufficient to produce the protection from UVA. Additionally, beta-carotene is phytoprotective (plant-derived protection) against erythema (redness of skin produced by the congestion of capillaries in the skin) induced by UVA. To maintain the skin benefits associated with consumption of fruits and vegetables rich in beta-carotene, it is important to maintain consumption of those foods. Because UVA destroys beta-carotene in the skin, it must be replenished continuously. Keep eating your brightly-colored vegies. 1.Wertz, K., Seifert, N., Hunziker, P. B., Riss, G., Wyss, A., Lankin, C., and Goralczyk, R. Beta-carotene inhibits UVA-induced matrix metallo protease 1 and 10 expression in keratinocytes by a singlet oxygen-dependent mechanism. Free Radic Biol Med, 37: 654-670, 2004. 2.Stahl, W. and Sies, H. Bioactivity and protective effects of natural carotenoids. Biochim Biophys Acta, 1740: 101-107, 2005. 3.Bando, N., Hayashi, H., Wakamatsu, S., Inakuma, T., Miyoshi, M., Nagao, A., Yamauchi, R., and Terao, J. Participation of singlet oxygen in ultraviolet-a-induced lipid peroxidation in mouse skin and its inhibition by dietary beta-carotene: an ex vivo study. Free Radic Biol Med, 37: 1854-1863, 2004.