Echinacea Helps Boost Immune System

Taking echinacea (E. purpurea and E. angustifolia), by itself or in combination with larch arabinogalactan, may enhance the functioning of a specific part of the immune system, according to a study in Alternative Medicine Review (2002;7:138–49). This is one of the first human studies to examine how echinacea affects immune function.

Echinacea is widely used in Europe and is one of the most popular over-the-counter herbal supplements sold in the United States. Several studies have shown that echinacea helps reduce the time to recover from colds and flus, but the mechanism by which it has this effect has not been clearly identified. A few small studies have shown that larch arabinogalactan (derived from Larix occidentalis) may also have immune-stimulating properties. The goal of this current study was to determine if echinacea, larch arabinogalactan, or their combination would have an affect on immune function.

Forty-eight healthy women were assigned to receive one of six treatments for four weeks: (1) an extract of E. purpurea, (2) E. purpurea and E. angustifolia, (3) ultra-refined E. purpurea and E. angustifolia, (4) E. purpurea, E. angustifolia, and larch arabinogalactan, (5) larch arabinogalactan, or (6) placebo. Measurements of complement properdin, a marker of immune function, were taken initially and at the completion of the study.

After four weeks of treatment, those taking E. purpurea and E. angustifolia and also those taking E. purpurea, E. angustifolia plus larch arabinogalactan had significant increases in complement properdin by 21% and 18%, respectively. Individuals in those two treatment groups also showed improvements in overall physical and emotional health.

The findings of this study suggest that echinacea, with or without larch arabinogalactan, may boost a part of the immune system that is ultimately responsible for destruction of viruses and bacteria. Larch arabinogalactan by itself did not increase complement properdin, but, based on previously published studies on larch, the duration of the study may have been too short to notice any significant change in immune function. Although it is still not entirely clear how these herbs work, both substances are reasonably safe and may be useful for the short-term treatment of colds and flus.

Darin Ingels, ND, MT (ASCP), received his bachelor’s degree from Purdue University and his Doctorate of Naturopathic Medicine from Bastyr University in Kenmore, WA. Dr. Ingels is the author of The Natural Pharmacist: Lowering Cholesterol (Prima, 1999) and Natural Treatments for High Cholesterol (Prima, 2000). He currently is in private practice at New England Family Health Associates located in Southport, CT, where he specializes in environmental medicine and allergies. Dr. Ingels is a regular contributor to Healthnotes and Healthnotes Newswire.

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