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Are Antioxidants Worth the Hype?
By: Ahmed Abdullah, MD
Posted: October 27, 2010, from the November 2010 issue of Skin Inc. magazine.
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In fact, only 33% of adults are getting the recommended allowance of fruit and only 27% are getting the recommended allowance of vegetables.6 To determine the number of antioxidants in a food, supplement or skin care product, most look to the Oxygen Radical Absorbance Capacity (ORAC) scale. According to this scale, the top five foods for antioxidant content are ground cloves, sumac, ground cinnamon, sorghum and dried oregano. This is in addition to the many foods that have become trendy for their antioxidant capacity, including acai berry, pomegranate and goji berry. (Editor’s note: To find the ORAC values of various foods, log on to www.oracvalues.com.)
The concern, however, is that use of the ORAC scale has led to competition among manufacturers to develop product formulations with the highest antioxidant content. Although that hardly seems like a negative at face value, consider that a study demonstrated that ingestion of too-high levels of certain antioxidants might have a negative impact on health. Vitamin C, for example, has exhibited pro-oxidant characteristics, actually inducing oxidation when ingested at quantities greater than 500 mg.7 Keep in mind that this is a single study and, therefore, doesn’t prove anything. After all, vitamin C is water-soluble and excessive amounts in the body are excreted. Additionally, high dosages have been found beneficial in reducing the frequency and severity of colds.8
What the vitamin C study demonstrates is that there is indeed more that must be learned regarding how high levels of antioxidants behave in the body. In fact, just recently at the 2010 Annual Meeting of The American Academy of Dermatology (AAD), the Coppertone Solar Research Center released the results of a study that showed the use of certain topical antioxidants in sunscreen reduced the formation of free radicals by 74% in the skin’s outer layers exposed to UV. However, that research also showed that some topical antioxidants, including some plant extracts, transformed into pro-oxidants when exposed to UV light.9
Perhaps the biggest unknown when it comes to the use of topical antioxidants is the antioxidant-absorption capacity of the skin. It is not yet concretely known how many of the antioxidants that are topically applied are absorbed into the deeper layers of the skin. And, of those that are absorbed, does the skin actually utilize them? Answers to these questions may vary depending on the antioxidant being applied.
In 2009, a team of fellow researchers, including the author of this article, implemented a study to determine the effects of skin moisturizers containing antioxidants on total antioxidant capacity (TAC) of human skin.10 The team found that it is indeed beneficial to use a topical skin care product that includes antioxidants, because they increase antioxidant levels within the skin. Furthermore, another study demonstrated that, when applied topically in proper form, antioxidants such as vitamins C and E and selenium “arm the skin with a reservoir of antioxidants that cannot be washed or rubbed off, a protection which stays in the skin for several days after application.”11