Echinacea is one of the most commonly used medicinal plants in the western world and was the top-selling herb in the United States in 2002.^1,2 Market statistics for 2000 indicate that $58.4 million was spent on Echinacea products in the United States at “mass market” outlets.² 

Echinacea-containing products and phytopharmaceuticals available in the market⁴. In Germany, Echinacea is approved for oral use to treat respiratory and urinary tract infections and for topical use to treat wounds.³

The composition of all herbal medicine can differ, depending on the location where the herb is grown, season harvested, method extracted, and the way it has been stored. In addition, the variation in composition of Echinacea preparations sold in the market is due to the use of different species of Echinacea or part of the plant used.

The following review summarises the clinical effectiveness for Echinacea, the correct dosage to use, and parts of the plant used.

The history of Echinacea

The genus Echinacea (coneflower, family Asteraceae) is a common plant found in the central and eastern parts of the United States. The two main medicinal herbs used in Australia are the Echinacea Angustifolia (regarded as the more potent plant) and the Echinacea Purpurea species. Echinacea has been widely used by Native Americans and later white settlers for infections and ‘blood cleansing’.

MEDICAL USES OF ECHINACEA

Immune boosting effects

Antibiotics kill bacteria by directly damaging their cellular membrane, resulting in their death. This is why viruses are not affected by antibiotics as they do not have cellular membranes. Unlike antibiotics however, Echinacea kills bacteria and viruses by boosting the body’s own immune system to destroy the invaders.

Studies have been done to examine the effect of Echinacea on the immune system, either by adding it to extracted white blood cells (our immune cells) or giving it to humans and then extracting the white blood cells. These studies demonstrate an increase in white blood cell activity and bacteria-killing activity against staphylococcus infection. Increased production of other immune boosting chemicals (tumour necrosis factor and interleukin (IL-6 and IL-1) has also evidenced.⁵ Another study showed that extracted white blood cells responded to application of Echinacea Purpurea juice by producing more immune boosting chemicals (tumour necrosis factor, IL-6, and IL-1)⁶. The extracts from Echinacea, when applied to immune cells resulted in an increase of the overall killing ability of the white blood cells.⁷

Echinacea for infections

A number of studies have been conducted to assess the efficacy of various Echinacea products to treat and prevent upper respiratory tract infections (URI’s) in adults. The results of critical reviews of these studies indicate that the evidence for the efficacy of Echinacea as a treatment in adults is fairly strong. Of the published Echinacea prevention studies in adults, at least six included a placebo control group (making the study more valid). The results of these prevention trials suggested a 12%–20% reduction in the subsequent occurrence of upper respiratory infections after Echinacea treatment.⁸

One study found that Echinacea Purpurea may help to prevent colds and flu in children. Results suggested that Echinacea Purpurea, when taken as a treatment for an initial upper respiratory tract infection, may prevent subsequent upper respiratory tract infections. In this secondary analysis of data from a randomized controlled trial, the risk of subsequent upper respiratory tract infections in children that had received treatment with Echinacea was 28% lower than children who received placebo. A decrease of this magnitude in the number of upper respiratory tract infections per year could have a large public health impact, given that up to 40% of visits to paediatricians in the Winter months by children 1–5 years old are because of cough and URI symptoms.⁸

Contraindications of Echinacea

Echinacea is generally regarded as a safe herb however it should be avoided during pregnancy unless professionally prescribed. Boosting certain aspects of the immune system during pregnancy can lead to certain complications. Although the adverse effect profile and tolerability of this herb are excellent, long-term safety studies are lacking so check with your health care practitioner before taking this herb long-term.

Higher dosages may be contradicted in some individuals suffering from inflammatory conditions where the immune system is already overactive (such as Arthritis). Again, please speak to your practitioner about the suitability of this herb for you.

Drug interactions with Echinacea

Although Echinacea, like any herbal medicine, can be contra-indicated with medications, no significant herb/drug interactions with Echinacea have been reported. However, as a precaution it is advised that before using this herb or any other herbal preparation, to consult your health care professional.

Therapeutic/safe dosages of Echinacea

For freeze-dried extract, the dosage is 1 to 2 capsules three times per day. For dry powdered extract (standardized to 3.5% echinacoside), use 300 mg three times per day. If you are using a liquid extract (1:1), 1/4 to 1/2 teaspoon three times daily is suitable. For the dried root or tea, 0.5 to 1 g three times per day is an ideal dosage.⁹ A qualified herbalist may prescribe higher dosages for acute infections.

The dose and duration for taking Echinacea

Studies have found that short and long-term consumption of Echinacea is beneficial for the treatment and prevention of infections. It is advised that you take Echinacea at the first sign of a cold or flu. Alternatively, taking a lower dose over a few months during Winter will also benefit your immune system.

Other herbs that can be used with Echinacea

As with many herbal preparations, herbs are often combined to make a formula. This formula usually contains herbs with a similar action thus improving the effectiveness over a single herbal preparation. Herbs that are commonly found with Echinacea for the treatment of infections include:

•     Golden Seal. This is a great herb for drying mucus and also boosting the immune system. Golden Seal increases similar, but different immune boosting chemicals in the body. It also directly kills infections in a similar way to antibiotics.

•     Garlic. Best known for its pungent odour and pleasant taste, garlic is also one of nature’s best antibiotics. While garlic kills microbes directly, it also has a wonderful immune stimulation effect.

•     Astragalus. Astragalus benefits the immune system by firing up the white blood cells to kill microbes. Studies have also found that it reduces the effects of bacterial and viral infections including the flu and hepatitis, while also being beneficial for AIDS sufferers. Host herbalists recommend Astragalus for moderate to long-term uses.

Conclusion