Black elder, or Sambucus nigra, has been a popular medicinal herb since at least the fifth century. A member of the honeysuckle family, elderberry is mentioned in the writings of Hippocrates, Dioscurides, and Plinius, and it can be found in every pharmacopoeia known to date. Elderberry wine was traditionally used to treat influenza and related myalgias and fevers. Nicknamed “nature’s flu fighter,” products of concentrated elderberry juice have been proven useful in shortening the duration of influenza symptoms in more than 50% of cases.1

Background

Historically, the black elderberry has been extremely popular throughout the Native American culture and became highly prized by the earliest Spanish explorers.2 The deciduous shrublike tree grows 2-4 m in height and has pinnate clusters of green pointed leaves. Left to themselves, elderberry shrubs can live 80-100 years.3 However, the number of elderberry shrubs remaining in North America has dwindled significantly over the past few decades due largely to the widespread use of pesticides and the urban development of many native growth areas.

Black elderberry shrubs flower in July and August, giving rise to small clusters of purple-black shiny round berries.2 While the raw berries are technically edible, they should not be consumed in large quantities because of the potential for cyanide poisoning.2 Most elderberries are cooked into jams, syrups, or pies, or they are distilled into wine.2 In addition to being extremely rich in vitamin C (36 mg per 100 g of fruit), elderberry concentrate has been found to contain at least three active flavonoids thought to be responsible for its potent healing properties.4

Science

In a study of 12 healthy participants, the use of a patented elderberry extract marketed and sold under the brand name “Sambucol” showed a significant increase in the production of inflammatory cytokines, with the most striking increase seen in the production of tumor necrosis factor-α.5 These findings demonstrated a significant upregulation of the healthy immune system.

In a second study, 60 patients who presented with flulike symptoms for 48 hours or less and who had not had flu vaccinations were enrolled in a randomized, double-blind, placebo-controlled study. After receiving elderberry syrup 15 mL four times daily for five days, the active treatment group showed symptom resolution four days earlier than the placebo group.6

Yet another double-blind trial of 27 patients also showed that participants in the active treatment group recovered in three days vs. six days for placebo. This apparent antiviral action is provided by the main flavonoids cyanidin 3-glucoside and cyanidin 3-sambubioside. Antiviral activity has been confirmed against influenza A and B as well as influenza B/Panama.6

A literature search confirms that Sambucol is the original patented formulation of black elderberry,1 but other brands and types of supplement now exist. Dosing has only been established for the Israeli-produced Sambucol.6 Some formulations add other immunity-boosting herbs and supplements, such as echinacea and raw honey.

Elderberry’s immunity-enhancing properties have prompted some sources to recommend a small daily dose as a preventative measure for viral illnesses. The suggested dose of these formulations is one tablespoon daily (one quarter of the treatment dose for acute illness). While this approach seems logical, there are no data to support it.

Despite efficacy against other influenza viruses, no human studies support elderberry’s efficacy against avian flu. Obviously, if the antiviral activity is more general and not specific to certain strains, then there could be some overlap of efficacy, but studies confirming this are lacking. One corporate-sponsored study showed a 90% reduction of intracellular HN51 (avian) flu virus in dogs, but this has yet to be replicated in humans.7

Safety, cost, how supplied

There is a potential for allergic reaction, and persons taking elderberry for the first time should use a test dose and observe for reaction before continuing with treatment. As previously noted, unripe berries (as well as any of the green parts of the plant) should be considered poisonous because of cyanide accumulation.4 In addition, uncooked or unripe elderberries are toxic and can cause nausea, vomiting, or severe diarrhea.8 Because of possible diuretic effects, use caution if taking elderberry with drugs that increase urination.8 No other significant drug or herb interactions have been identified.4

Consumption by women who are pregnant or lactating should be avoided unless advised by a clinician. Safe use in children has not been verified.

The patented concentrate mentioned is the most tested form. Cost is minuscule, however, when compared with the prescription equivalents, such as oseltamivir. Numerous teas, tinctures, capsules, and other forms of elderberry are readily available.

Taken in doses of 15 mL (approximately 0.5 oz) four times a day for five days, a course of elderberry syrup can cost anywhere from $25 to $30, with each 4-oz bottle costing on average $8-$12. This trumps oseltamivir and zanamivir, each of which typically costs well over $75 per course.9

Summary

A good shelf stock of black elderberry syrup is a must during the flu season. In spite of widespread vaccination, influenza still affects the health of many, and the next best thing to preventing it completely is a speedy recovery.

Ms. Sego is a staff clinician at the Veterans Administration Hospital in Kansas City, Mo., where she practices adult medicine and women’s health. She also teaches at the nursing schools of the University of Missouri and the University of Kansas.

References

1. AltHealth. Study shows Israeli elderberry extract effective against avian flu. Available at www.althealth.co.uk/news /article.php?id=1856. Accessed April 7, 2008.

2. United States Department of Agriculture National Resources Conservation Service. Common elderberry. Available at http://plants.usda.gov/plantguide/pdf/cs_sanic4.pdf. Accessed April 7, 2008.

3. Wikipedia. Sambucus. Available at http://en.wikipedia.org/wiki/Sambucus. Accessed April 7, 2008.

4. Skidmore RL. Mosby’s Handbook of Herbs & Natural Supplements. 3rd ed. St. Louis, Mo.: Elsevier Mosby; 2006:405.

5. Barak V, Halperin T, Kalickman I. The effect of Sambucol, a black elderberry-based, natural product, on the production of human cytokines: I. Inflammatory cytokines. Eur Cytokine Netw. 2001;12:290-296.

6. Zakay-Rones Z, Thom E, Wollan T, Wadstein J. Randomized study of the efficacy and safety of oral elderberry extract in the treatment of influenza A and B virus infections. J Int Med Res. 2004;32:132-140.

7. Nutra Ingredients. Sambucol fights bird flu virus in lab. Available at . Accessed April 7, 2008.

8. National Center for Complementary and Alternative Medicine. European elder. Available at http://nccam.nih.gov/health /euroelder. Accessed April 7, 2008.

9. Weil. A sure cure for the flu? Available at www.drweil.com /drw/u/id/QAA300839. Accessed April 7, 2008.