For years now, purveyors of various foods and supplements have pitched their products as being better for health because of the so-called "antioxidant" properties of their constituents. The theory is that highly reactive molecules, called oxygen free radicals or just free radicals, can stimulate the occurrence of diseases like arthritis, atherosclerosis, and various types of cancer.
Some white blood cells called neutrophils actually produce free radicals, and have been thought to use them to kill invading microbes such as bacteria. These free radicals, working with enzymes also produced by the cells, supposedly were crucial for the disease-fighting process. A recent scientific study challenges this theory, however.
Researchers at the University College London used a strain of mouse that was unable to produce the usual complement of microbe-destroying enzymes but still could produce free radicals. These mice were unable to resist infections by bacteria and yeasts, indicating that the free radicals they produced were not able to protect them. One of the authors said that because people whose neutrophils can't produce free radicals are prone to severe infections, it's been assumed that the free radicals themselves were highly toxic and could damage human tissues. But, he continued, "our work shows that the basic theory underlying the toxicity of oxygen radicals is flawed."
This study must be replicated, of course. If it is, though, it indicates that a theory of disease causation needs to be revised, and that perhaps antioxidant supplements and medications may not be such a great investment after all.
Ruth Kava, Ph.D., R.D., is Director of Nutrition at the American Council on Science and Health.
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| Responses:
March 9, 2004 I rely heavily on ACSH's HealthFactsandFears for practical perspective in my practice as an environmental health professional. I've been in the EH&S business for nearly twenty-five years, and I've seen more people relieved of allergy, asthma, and asthmatic bronchitis symptoms through the use of antioxidants than with the standard approach (i.e., prescription drugs). I've also seen many other symptoms significantly reduced or eliminated (e.g., fibromyalgia, chronic fatigue, etc.). Antioxidants have a remarkably positive history of efficacy which has been very well documented. Dr. Kava may have "tipped her cards" in the opening sentence by stating that she believes "purveyors of various foods and supplements have pitched their products as being better for health." Don't be so ambiguous, doctor. What exactly is your opinion of those who dare to help people with natural substances with essentially no side effects versus prescribing chemicals (i.e., pharmaceuticals) with significant potentials for adverse effects? I strongly support ACSH's efforts to bring credibility to the field of public health. However, I urge ACSH to be a little more hesitant to publish blanket statements such as Dr. Kava's, which only reveal a likely bias and provide little scientific support one way or the other. Dan Feldt, MS, MPH, CIH Kava replies: We at ACSH prefer products and techniques that have some scientific backing rather than just ones labeled "natural." Although the word has come to be taken as if it were almost synonymous with "safe," that is a misconception. There are many natural products that are not safe and many synthetic pharmaceuticals that are. Making a sweeping distinction is inaccurate and misleading. Similarly, the term "antioxidant" is being widely used and has come to be trusted as though always implying good for human health. That this may not be the case is demonstrated by the paper I described. These labels natural, antioxidant, synthetic have become so broadly used that they are well on their way to losing all meaning. March 16, 2004 Dr. Kava, I'm not sure if you show an air of cynicism or arrogance in stating that "we at ACSH prefer products and techniques that have some scientific backing rather than just ones labeled 'natural'." Regardless, I'm sure you are familiar with the internationally acclaimed organization, the American Academy of Anti-Aging Medicine, and founders Dr. Goldman and Dr. Klatz. I'd refer you to this organization and their prominent nutritional and anti-aging resources for factually based, scientifically-verified information on antioxidants and I'd suggest you check with them prior to publishing opinions lacking "scientific backing" (to use your words). Dan Feldt, MS, MPH, CIH |
