They make our food colorful, and they tend to our free radicals, but can the organic substances known as antioxidants prevent cancer, heart disease and other health conditions?
For a clear understanding of antioxidants, it is critical to examine those that are currently in the limelight, considering both expert opinions and clinical trials. Recent studies conducted on some of the most popular antioxidants, such as vitamin E, may sway supplement shoppers toward better health if retailers are prepared with an armory of supplement information, says one expert.
?You really need to learn how to assess what you?re pitched,? says Anthony Almada, a biochemist and founder of Imaginutrition Inc., a Laguna Niguel, Calif.-based think tank focused on nutritional technologies and clinical research validation. ?Do your research. Find studies that evidence the effectiveness of products, or better yet, ask product marketers to provide studies.?
Almada asserts that just because a substance is an antioxidant doesn?t mean it is safe or ultimately beneficial for every body: ?Blueberries could have very powerful antioxidant effects in a test tube, but the question remains: Do substances like blueberries have a very powerful antioxidant effect in my body after I take them for a month or more?
?You absolutely need to look for studies that have been done over the long term. Some antioxidants seem great, but when taken for three, five or six years, some have shown undesirable or nonpositive effects,? he adds.
One such long-term study conducted by scientists at Laval University Cancer Research Center in Quebec and published in the International Union Against Cancer Journal in 2005, demonstrates that for men at high risk for prostate cancer, supplementation with antioxidants such as vitamins C and E, beta-carotene, selenium and zinc daily for eight years was only moderately effective in reducing cancer rates.
However, the same study indicated that for men at normal risk for prostate cancer, supplementation with antioxidants had very positive effects. ?Our findings support the hypothesis that chemoprevention of prostate cancer can be achieved with nutritional doses of antioxidant vitamins and minerals,? the study researchers say.
A darkening sheep among its antioxidant counterparts, vitamin E is under increasing scrutiny and has become the source of considerable controversy among natural health advisers. In a 2005 observational study published in the Annals of the New York Academy of Sciences, Dr. J. Michael Gaziano, from Brigham and Women?s Hospital?s division of aging in Boston, writes, ?In many, but not all, of these studies, vitamin E intake over an extended period was associated with decreased risk of cardiovascular events. Overall, they support the possibility that vitamin E intake, either from food or supplements, may reduce risk of cardiovascular disease. However, these studies have important limitations.?
It is precisely these limitations that keeps the American Heart Association from recommending population-wide use of vitamin E supplements in disease prevention, as noted by Gaziano. In his observational study, Gaziano also states that in 2002, the Institute of Medicine concluded that evidence suggests the relationship between vitamin E supplement use and coronary heart disease is uncertain.
In another long-term study published in the Journal of the American Medical Association in 2005, scientists suggested that vitamin E not only fails to prevent cardiovascular events, but also lacks effectiveness in treating cancer. ?The daily administration of 400 IU of natural-source vitamin E for a median of seven years had no clear impact on fatal and nonfatal cancers, major cardiovascular events or deaths,? the study researchers stated.
Scientists conducting the trials concluded that vitamin E might even have negative health effects. ?We observed an increase in the risk of heart failure, which is troubling,? the study reads. ?In conjunction with its lack of efficacy, the potential for harm suggested by our findings strongly supports the view that vitamin E supplements should not be used in patients with vascular disease or diabetes mellitus.?
This study supports earlier research conducted by many of the same researchers and published in The New England Journal of Medicine in 2000 that concludes vitamin E is decidedly ineffective at treating or preventing coronary heart disease and atherosclerosis.
So, for those hoping to fend off heart troubles, especially those already diagnosed with vascular disease or diabetes, vitamin E may not be the best ticket to health. But that doesn?t mean that everyone should avoid vitamin E. Even Almada, despite his attention to recent research, still takes vitamin E supplements a couple times a week, along with N-acetyl cysteine for its restorative effects on the liver, milk thistle for its detoxification qualities, vitamin C, and a combination of grape seed and grape skin for boosting immunity.
Almada says that for him, vitamin E and a host of several other carefully chosen antioxidants are appropriate. But everyone is different. Marianne Marchese, N.D., clinical practitioner at the National College of Naturopathic Medicine?s Natural Health Center in Portland, Ore., with a specialty in environmental medicine, agrees with Almada?s sentiment.
?I don?t typically recommend my regular patients take extra antioxidants,? she says. ?However, I see a lot of patients suffering from conditions related to toxins in the environment. These people need extra antioxidants because toxins generate free radicals in the body. I put them on a comprehensive cleansing program, including supplements, to increase the body?s main antioxidant, glutathione.?
In particular, Marchese recommends selenium, NAC, vitamin C and the amino acids that make up glutathione: glutamine, glycine and cysteine. ?Alpha lipoic acid is an important antioxidant I also often use with my environmental medicine patients. I will even give IV glutathione,? she adds. Chris Spooner, N.D., post-doctoral fellow in environmental medicine at the Southwest College of Naturopathic Medicine in Tempe, Ariz., says that everyone should start with a basic combination of antioxidants, perhaps in a multivitamin. ?Antioxidants are critical to everything we do,? he says. A vitamin C proponent, Spooner defends antioxidants and says that each type plays an important role in every body. ?If I had one supplement that I would recommend if stranded on a toxic waste dump island, to benefit everyone, I would say vitamin C, without question. Vitamin E is also part of a team of antioxidants that are really important in protecting us from environmental toxins. It all depends on a person?s needs.?
?Antioxidants should be recommended on a case-by-case basis,? says Matthew Becker, lead practitioner at Pharmaca in Boulder, Colo., and faculty member at the Rocky Mountain Center for Botanical Studies. While Becker prefers to take resveratrol, an antioxidant found in grapes, along with grape seed extract, milk thistle and coenzyme Q10, he too cautions that everyone is different and each body requires a different combination of antioxidants and other supplements to aid in wellness.
The short answer to the issue of antioxidant supplementation, as stated by Becker and reiterated by other health care professionals, is: ?It all depends on the individual, so it?s best to know what?s available, in terms of antioxidant products, and what?s best for different health needs.?
Anne Burnett is a freelance writer, magazine editor and science teacher in Denver.
Natural Foods Merchandiser volume XXVI/number 9/p. 84, 88