Thursday, January 11, 2007

Response to NPR report on supplements and colds

Stress, Nutrition and Colds By Neil E. Levin, CCN, DANLA, January 11, 2007 The NPR Morning Edition story airing today called “Low-Stress Life May Be Best Way to Prevent Colds” has some contradictions and inaccuracies. While I can’t defend the “Airborne” formula, which has non-standardized herbs and non-natural ingredients and was developed by a teacher rather than a nutritionist, some of the statements about dietary supplements made in the report are simply inaccurate. One is the purported lack of connection between boosting the immune system and preventing or treating the common cold or flu, reporting the views of one skeptical medical researcher. In fact, there are many hundreds of published clinical studies showing specific mechanisms by which various dietary supplements can improve immune cell function. A review of the published science on zinc in the Journal of Environmental Pathology and Toxicology stated that “[zinc] fulfills an immune function.” The Journal of Applied Microbiology and Biotechnology published a review reporting that, “Garlic has a wide spectrum of actions; not only is it antibacterial, antiviral, antifungal and antiprotozoal, but it also has beneficial effects on the cardiovascular and immune systems.” Alternative Medicine Review recently published a review of the literature on the effects of herbs on the immune system, reporting, “The in vitro and in vivo research demonstrates that the reviewed botanical medicines modulate the secretion of multiple cytokines.” [immune cells] And the journal Autoimmunity bluntly reported on Echinacea’s positive effect on Natural Killer immune cells, indicating that Echinacea may even provide a new treatment for Type 1 Diabetes: “the fact that the herb, Echinacea, is a well demonstrated immunostimulant of NK cells in normal mice/humans,” and concluding that “The results revealed that, in NOD mice, dietary Echinacea…actually stimulated NK cell production in their bone marrow birth site.” Another mistaken claim is that “most people get plenty of that [Vitamin C] in their diet. Yet according to dietary data from the National Health and Nutrition Examination Survey, “We conclude that despite NHANES III data indicating a small increase in the median dietary vitamin C ingestion in the USA, a substantial fraction of the population still ingests vitamin C at or below the Recommended Dietary Allowance.” The RDA is only 60 mg a day. This links to another part of the report that links stress to a two-fold increase in colds. Vitamin C aids adrenal function, with that gland being the most prominent player in stress response. Vitamin C levels in the adrenal gland are reported to be as great as 150 times the general levels in the bloodstream. Of course, if people don’t get enough in the diet and are under stress, that easily explains the vitamin C connection. The report also stated that some formulas contain, “herbs such as Echinacea, which, although very popular, has been shown by the best scientific studies not to work.” Yet recent negative reports have been challenged by the non-profit American Botanical Council (ABC) as not using commercially available preparations and using lower doses less frequently than commonly and previously used in positive studies. Another criticism is that some studies used college students that typically have better immune system functioning than elderly people. ABC Executive Director Mark Blumenthal said in response to one recent study that, “This is not a definitive trial on the efficacy of echinacea, nor should the results be generalized to echinacea preparations widely available. Unfortunately, the conclusion that may be drawn by some media who report this study may state that ‘echinacea is ineffective,’ but this would be an incorrect conclusion based on the design of this study and the evidence in the existing literature.” A meta-analysis of previously published studies on echinacea was published in the journal Clinical Therapeutics, with the conclusion, “Based on the analysis, the likelihood of experiencing a clinical cold was 55% higher with placebo than with Echinacea.” Another published review says that, “Numerous clinical trials have been carried out on echinacea preparations: it appears that the extracts shorten the duration and severity of colds and other upper respiratory infections (URIs) when given as soon as symptoms become evident.” The NPR report also questions the ability of the mineral zinc to reduce colds. Yet a report by the physician-reviewed health education group A.D.A.M. ( states, “Several important studies have revealed that zinc lozenges may reduce the intensity of the symptoms associated with a cold, particularly cough, and the length of time that a cold lingers.” Such misleading statements in a health report may lead people to think that there are no dietary supplements that can correct deficiencies and imbalances which, combined with stress, may lead to impaired immune function. But science shows that the opposite may be true: dietary supplements have a solid role in immunity and health. Neil Levin is a board certified clinical nutritionist who is a product formulator and the nutrition educator for NOW Foods, a manufacturer of dietary supplements. His nutrition blog is available at REFERENCES: Link to original NPR report: Frassinetti S, Bronzetti G, Caltavuturo L, Cini M, Croce CD. The role of zinc in life: a review. J Environ Pathol Toxicol Oncol. 2006;25(3):597-610. Review. PMID: 17073562 Harris JC, Cottrell SL, Plummer S, Lloyd D. Antimicrobial properties of Allium sativum (garlic). Appl Microbiol Biotechnol. 2001 Oct;57(3):282-6. Review. PMID: 11759674 Spelman K, Burns J, Nichols D, Winters N, Ottersberg S, Tenborg M. Modulation of cytokine expression by traditional medicines: a review of herbal immunomodulators. Altern Med Rev. 2006 Jun;11(2):128-50. Review. PMID: 16813462 Schoop R, Klein P, Suter A, Johnston SL. Echinacea in the prevention of induced rhinovirus colds: a meta-analysis. Clin Ther. 2006 Feb;28(2):174-83. Review. PMID: 16678640 Block KI, Mead MN. Immune system effects of echinacea, ginseng, and astragalus: a review. Integr Cancer Ther. 2003 Sep;2(3):247-67. Review. PMID: 15035888 Delorme D, Miller SC. Dietary consumption of Echinacea by mice afflicted with autoimmune (type I) diabetes: effect of consuming the herb on hemopoietic and immune cell dynamics. Autoimmunity. 2005 Sep;38(6):453-61. PMID: 16278152 Herbal Science Group Says Dosage Too Low in New Echinacea Trial Patak P, Willenberg HS, Bornstein SR. Vitamin C is an important cofactor for both adrenal cortex and adrenal medulla. Endocr Res. 2004 Nov;30(4):871-5. Review. PMID: 15666839 Kurugol Z, Akilli M, Bayram N, Koturoglu G. The prophylactic and therapeutic effectiveness of zinc sulphate on common cold in children. Acta Paediatr. 2006 Oct;95(10):1175-81. PMID: 16982486 Hulisz D. Efficacy of zinc against common cold viruses: an overview. J Am Pharm Assoc (Wash DC). 2004 Sep-Oct;44(5):594-603. Review. PMID: 15496046

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