July 2009 Issue
A Nutritious Approach to Healthier Skin
By Kandis Driscoll and Hawley Almstedt, PhD
Today’s Dietitian
Vol. 11 No. 7 P. 44
Can certain vitamins in nutrient-based skin care products truly be effective in treating conditions such as psoriasis?
Acne, psoriasis, wrinkles, fine lines, blotches, rosacea, dryness, redness, dark spots, and blackheads. These are only a few of the skin conditions that affect millions of people every day. Thousands of cosmetic products promise to “fight skin damage,” “increase firmness,” and “reduce the signs of aging,” and consumers spend $8 billion on them each year, hoping to achieve younger looking, flawless skin.1,2 Their desire is understandable, considering that skin plays a critical role in physical attractiveness. A skin disorder can greatly affect an individual’s appearance and impact self-esteem.
Surface texture, color, elasticity, and sebum production help determine skin’s appearance.3 Adequate hydration in the stratum corneum, the outermost layer of the epidermis, is crucial for a general appearance of soft and smooth skin, especially since the keratin in this layer absorbs water and prevents its evaporation.3 Many skin conditions result from the damaging effects of ultraviolet light, free radicals, and toxic and allergic compounds, while others may be due to genetic and environmental factors. Manufacturers spend much time and effort combining ingredients and nutrients that they believe will most effectively treat these skin conditions, giving consumers a capsule of hope.
But what exactly do these products contain, and how effective are certain ingredients for combating common skin conditions?
Nutrient-Based Products
Nutrient-based products have become popular treatments in skin care. Vitamins A, D, C, and E have been used in a variety of skin care products and may provide healthful benefits and treatment.
The many vitamins in Jergens Skincare purportedly restore smoothness while protecting against environmental damage.1 A Neutrogena product line promises to fight skin damage and increase firmness, while Clinique’s Stop Signs Visible Anti-Aging Serum may decrease the look of lines and wrinkles due to its vitamin C content.1 L’Oreal says the vitamin E in its Plenitude Futur-e can help one maintain younger looking skin, since the micronutrient protects against the damage of free radicals.
Although people can acquire all of these vitamins from dietary sources and reap similar benefits, skin care manufacturers assert that applying vitamins directly to the skin accentuates their healthfulness. For example, the derivative forms of vitamin A, such as retinoic acid, may help reverse the effects of sun damage by thickening the inner living layers of the epidermis, and vitamin C’s ability to synthesize collagen is perhaps the reason why some manufacturers say the micronutrient reduces the look of fine lines.1
Vitamin A
Skin care products contain many forms and derivatives of vitamin A. Retinol is the most common one used in over-the-counter products; however, it remains stable for only 16 hours once exposed to room temperature, oxygen, or light.1 A physician must prescribe retinoic acid because it inhibits the enzymes that break down collagen to keep skin firm.1
The various forms of vitamin A and the potential effects that each derivative has on treating skin conditions explains why it has been used in dermatology since the 1940s.4 Vitamin A has shown to be particularly effective for treating acne vulgaris, an inflammation of the skin that occurs when dead skin cells clog pores.4,5 Some individuals can be genetically predisposed to acne, while for others it can occur more naturally. Other factors influencing the development of acne include hormones, certain medications (eg, anabolic steroids), and environment.6 It is the most common skin disorder, affecting more than 80% of the population to different degrees.7
When acne develops, two forms of the retinoid, isotretinoin and tretinoin, can be used to treat it. Isotretinoin, or cis-13 retinoic acid, has dramatically improved the management of severe acne since 1980.4 One of the common oral capsules that physicians prescribe is Accutane, which is given only to patients who suffer from severe cystic acne and show little benefit from other aggressive topical and oral treatments.5 This retinoid works to suppress the activity of sebaceous glands by decreasing sebum production.7 As a result, facial bacteria cannot multiply as rapidly to promote further development of blemishes. After the use of isotretinoin, many people remain free of acne indefinitely—a long-term effect of the nutrient.4
Tretinoin has been used as a topical treatment for managing both inflammatory and noninflammatory acne.7 It has been deemed one of the most effective treatments for acne because it normalizes the scaling of the clogged pore and allows sebum to flow from the blemish while preventing further breakouts. Tretinoin has the ability to penetrate clogged follicles and make the cells within the plug less sticky while speeding the production of new cells for a clearer complexion.5
Vitamin D
Vitamin D is another nutrient that has been shown to be effective for treating harsh skin conditions, specifically psoriasis.
Psoriasis, a chronic inflammatory disorder that leaves skin with lesions, plaques, and a scalelike appearance, affects approximately 2% of the U.S. population.7,8 There are many dynamics that contribute to psoriasis, including genetic predisposition and other environmental and immunologic factors.8 Keratinocytes, the major cells of the epidermis, have a rapid proliferation rate of 36 hours when involved with psoriasis compared with 311 hours in normal skin.8 This is perhaps what causes the chronic inflammation that characterizes the skin condition.
Topical vitamin D has proven to be successful for treating psoriasis, primarily because it slows the growth of inflamed cells and encourages the separation of new cells.6 Vitamin D also inhibits the activation of T cells, which release proinflammatory cytokines; as a result, the inflammation may be reduced.7 Other analogues of vitamin D that regulate the proliferation of keratinocytes and contain a higher potency are being tested.6
Vitamin C
Vitamin C is best known for its antioxidant properties, although it also plays a role in collagen synthesis. Antioxidants, of course, act as the body’s defense against the damaging effects of free radicals, which can occur in the body during cellular metabolism or with exposure to certain environmental toxins, such as ultraviolet light and pollution. Vitamin C works along with other antioxidants to protect the skin by neutralizing free radicals.8 Ascorbate can be found in cellular fluid and is distributed in all layers of the skin, with greater concentrations found in the epidermis.7 A higher concentration may provide greater photoprotection to the epidermis, lessening the harsh appearance that ultraviolet light damage causes.
When the skin is exposed to a variety of stressors, such as ultraviolet light and ozone, the concentration of ascorbate decreases in the skin while actively working in exposed areas.7 So, the topical application of ascorbate can further protect the skin from the damaging effects of the sun while preventing inflammation. Although vitamin C has substantial effects when used individually, these effects are enhanced when used in conjunction with vitamin E.8
Vitamin E
Vitamin E has antioxidant properties like its counterpart, vitamin C.9 This means that vitamin E also has the ability to quench the effects of free radicals. In addition, like vitamin C, vitamin E is more concentrated in the epidermis than in the dermis, suggesting similar effects on the epidermis’ appearance.7 It is interesting to note that the concentrations of vitamin E in the stratum corneum of exposed skin, such as the cheeks and forehead, are 20 times higher than in unexposed areas, such as the upper arm.7
Combining vitamin E and vitamin C may help the stability of vitamin E and enhance its antioxidant effects. Alpha-tocopherol is the form most commonly used in topical products that contain vitamin E.7 Vitamin E has the ability to penetrate the dermal layers of the skin, where oxidation occurs, to protect against photoaging.9 When used in combination, vitamins C and E seem to provide powerful protection as antioxidants, helping skin fight its daily battle against ultraviolet light.
Too Good to Be True?
From the evidence presented, it would seem obvious that including vitamins in skin care products is beneficial for consumers with certain skin disorders, especially considering so many manufacturers promote their products for the healthful advantages these micronutrients provide. Vitamin A appears to be effective for treating acne, vitamin D has shown to be successful for soothing the harsh effects of psoriasis, and vitamins C and E act as antioxidants, protecting the skin from the damage of free radicals. The latter two micronutrients may offer enhanced effects when used in combination.
Many manufacturers have jumped at the opportunity to blend all of these advantages into one cream, lotion, or serum. However, consumers must consider whether manufacturers are using the appropriate derivatives of these vitamins for maximum effectiveness and healthful benefit.
There are compelling reasons to believe that the forms of vitamins found in many cosmetic products do not aid the skin in the intended manner. For example, research has indicated that most of the vitamin C purchased in stores in premixed creams is inactive.1 For vitamin C to remain stable, it must have a pH of 4 to 5. However, this low pH would irritate skin, so most of the creams that include vitamin C as an ingredient have a pH of about 7.1 This means that it would be practically impossible for manufacturers to include this micronutrient in their products at a beneficial level without damaging and possibly burning the skin.
The concentration of vitamin E in skin care products is often low and not enough to protect the skin as an antioxidant.9 Manufacturers may attempt to use esters of the chosen vitamin in the hopes that the activity of the micronutrient will remain stable.9 However, the photoprotective ability of vitamin E esters is not as pronounced when compared with pure vitamin E, suggesting that the effectiveness is limited.9
Some products use vitamin A esters that they claim convert to an active form when applied to skin, but there is no scientific evidence to support this claim.1 Other, more innovative products have attempted to use nanocapsules or microspheres to protect the stability of vitamin A so that it can be properly delivered to skin cells. Yet, when tested, there was very little vitamin A within the microspheres, and much of the other content on the outside lost its activity, suggesting that the effectiveness of these cosmetic products is also limited.1
Good Potential
Considering all aspects, it is probable that vitamins have the ability to treat and benefit the skin in healthful ways. The potential of their advantages seems endless when looking at the evidence provided by studies that have noted their usefulness. Thus, vitamins do have the potential to be effective at combating certain skin conditions, especially when present in their active forms.
— Kandis Driscoll is pursuing a bachelor of science degree in natural science at Loyola Marymount University in Los Angeles.
— Hawley Almstedt, PhD, is an assistant professor at Loyola Marymount University, where she teaches nutrition and exercise physiology in the department of natural science.
References
1. Anonymous. The truth behind vitamins in cosmetics. Tufts University Health and Nutrition Letter. 2000;18:8.
2. World Watch Institute. Matters of scale-spending priorities. 2000. Available at: http://www.worldwatch.org/node/764. Accessed October 26, 2008.
3. Boelsma E, Hendriks FJ, Roza L. Nutritional skin care: Health effects of micronutrients and fatty acids. Am J Clin Nutr. 2001;73;853-864.
4. Futoryan T, Gilchrest BA. Retinoids and the skin. Nutr Rev. 1994;52:299-310.
5. Novick NL. Saving Face. New York: Franklin Watts; 1986.
6. Lowe KE, Norman AW. Vitamin D and psoriasis. Nutr Rev. 1992;50:138-142.
7. Shapiro SS, Saliou C. Role of vitamins in skin care. Nutrition. 2001;17:839-844.
8. Doley J, Genebriera J. Integrating Therapeutic and Complementary Nutrition. Boca Raton, Fla.: CRC Press; 2006.
9. Thiele JJ, Ekanayake-Mudiyanselage S. Vitamin E in human skin: Organ-specific physiology and considerations for its use in dermatology. Mol Aspects Med. 2007;28:646-667.