Diets Rich in Vitamin C and Linoleic Acid May Delay Skin Aging

by | Aug 6, 2008 | 2007, Aging, Fats and Oils - General, Skin Health, Vitamin C

Written by Susan Sweeny Johnson, PhD, Biochem. Results suggest that higher intakes of vitamin C and linoleic acid and lower intakes of fats and carbohydrates were associated with better skin-aging appearance. 
When skin ages, it takes on a wrinkled and dry appearance. It also thins, loses elasticity and develops dark spots and spider veins. Smoking, sunlight exposure and being overweight have been shown to speed aging of the skin.(1, 2, 3)

Previous supplementation studies have suggested that vitamin C plays a role in skin collagen synthesis (4) and protects skin from sun damage.(5) Other studies suggested that supplementation with omega-3 fish oil could also protect the skin from sun damage.(6)

In a new cross-sectional study of 4025 women (40–74 years old), their dietary nutrient intake as opposed to supplement use was compared to the condition of their skin to see if consumption of certain nutrients in their regular diets affected skin aging. A trained dietician had each participant complete a survey to assess their intake of dietary nutrients during the previous 24 hours. Their skin was examined by trained dermatologists for the presence of wrinkles, skin thinning, and dryness associated with aging.

The data were adjusted for age, race, energy intake, education, sunlight exposure, family income, menopausal status, body mass index (BMI), supplement use, and physical activity. Smokers and nonsmokers were examined separately. Results suggest that higher intakes of vitamin C and linoleic acid (omega-6 fatty acids from plant sources) and lower intakes of fats and carbohydrates were associated with better skin-aging appearance independent of the above factors known to affect skin aging.

Higher vitamin C intakes were associated with a lower likelihood of a wrinkled appearance [odds ratio (OR) 0.89] and age-associated dryness (OR: 0.93).  Higher linoleic acid intakes were associated with a lower likelihood of age-associated dryness (OR: 0.75) and skin thinning (OR: 0.78). A 17-g increase in fat and a 50-g increase in carbohydrate intakes increased the likelihood of a wrinkled appearance (OR: 1.28 and 1.36, respectively) and skin thinning (OR: 1.37 and 1.33, respectively.

The omega-6 fatty acid, linoleic acid, is an essential fatty acid that cannot be produced in the body. Low intake of linoleic acid an lead to the presence of abnormalities in the skin (6), and this could be important in its role in skin-aging appearance.

It is interesting to note that topical vitamin C and vitamin A are associated with protection against sun damage and formation of wrinkles.(7, 8, 9)  Topical application of EPA has also been shown to protect against sun damage.(10)

The average US household spends about $125 dollars per year on skin care and cosmetic products. Professional skin care is one of the fastest-growing segments within the cosmetics and toiletries industry. The global market for professional skin care products is estimated at over $5 billion and has been growing at double-digit rates, compared with growth of only 4% for the global cosmetics and toiletries market.(11)

Sun damage of the skin leads to skin cancer of which melanoma is the most serious type. If it is recognized and treated early, it is nearly 100 percent curable. But if it is not, the cancer can advance and spread to other parts of the body, where it becomes hard to treat and can be fatal. While it is not the most common of the skin cancers, it causes the most deaths. The American Cancer Society estimates that in 2007, there will be 8,110 fatalities, 5,220 in men and 2,800 in women in the U.S. The number of new cases of melanoma is estimated at 59,940; of these, 33,910 will be in men and 26,030 in women.(12)

Source: Cosgrove, Maeve C., Oscar H. Franco, Stewart P. Granger, Peter G. Murray, and Andrew E. Mayes. “Dietary nutrient intakes and skin-aging appearance among middle-aged American women.” The American journal of clinical nutrition 86, no. 4 (2007): 1225-1231.

© 2007 American Society for Nutrition

Posted August 6, 2008.

References:

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  2. Guinot C, Malvy DJ, Ambroisine L, et al. Relative contribution of intrinsic vs extrinsic factors to skin aging as determined by a validated skin age score. Arch Dermatol 2002;138:1454–60.
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  10. Kim HH, Cho S, Lee S, et al. Photoprotective and anti-skin-aging effects of eicosapentaenoic acid in human skin in vivo. J Lipid Res 2006;47:921–30.
  11. See the MindBranch website.
  12. See the Skin Cancer Foundation website.