Echinacea: Boost immune System and Treat Colds, Flu and Infections!

It’s no wonder that echinacea has been in the spotlight for being the most popular herbal remedy for colds and upper respiratory illnesses. It’s the best-selling herb in America which means that it detracts from Big Pharma’s sales of the cold and flu remedies lining pharmacy shelves.

The media frenzy that exploited the study that appeared in the July 18, 2005, issue of the New England Journal of Medicine1 made a strong case against echinacea as a beneficial cold remedy. But the media’s information about the study was just as flawed as the study. And it’s curious that the study was released immediately prior to the revelation that a flu pandemic is imminent and that our government is trying hard (albeit, years too late) to come up with an effective vaccine.

You don’t have to be a genius to guess why the media went over the top in warning consumers that echinacea is worthless. (Could it be that the media was surreptitiously ballyhooing Big Pharma’s anti-viral agents—which will be, by the way, essentially worthless against a mutated avian flu virus that is expected to cause a pandemic?)

You can speculate for yourself as to why such a fuss was made over the study published in the New England Journal of Medicine. But we will tell you why the study was flawed, and why we still think that echinacea is one of the best anti-cold and flu remedies available.

What is echinacea?

Imagine yourself living in the Midwest during the nineteenth century. You come down with an infectious disease and are given a tincture of echinacea. You survive. Or imagine that you are a Plains Indian and are bitten by a rattlesnake. You drink an antidote made from echinacea, and an echinacea poultice is applied to your leg. The redness and swelling dissipate and you survive.2 These were typical reports of successful treatments using echinacea before 1909, when the Council on Pharmacy and Chemistry of the American Medical Association refused to recognize it as an active drug, stating, “in view of the lack of any scientific scrutiny of the claims made for it, echinacea is deemed unworthy of further consideration until more reliable evidence is presented in its favor.”3 It’s interesting how some things never change.

Echinacea, a perennial herb native to the midwestern and southeastern United States, has actually been used successfully for hundreds of years. Native Americans used it more than any other plant for treating illness and injury, including wounds, snakebites, burns, toothache, and joint pains.2 Although echinacea’s popularity waned with the advent of antibiotics, it became respected among herbal practitioners in Europe after the first scientific study in 1932. But it didn’t become a popular herb until the early 1980s, when consumers started investigating natural remedies to help immune disorders.4

Today, both the plant’s upper parts and roots are used for oral administration in the form of tablets, extracts, fresh pressed juice, teas, and tinctures. And because of its wide-range of healing properties, it’s not surprising that echinacea enjoys its place as the best-selling herbal extract in America, generating sales of more than 300 million dollars a year. It is also one of the top three herbal supplements most frequently used by the elderly.5

What is it for?

Echinacea has traditionally been used to:

  • treat or prevent colds, flu, and other infections
  • stimulate the immune system to help fight infections
  • heal wounds and skin problems, such as acne or boils
  • reduce inflammation

The common cold is probably the most common illness in America, leading to more doctor visits and absences from school and work than any other illness. In fact, it is estimated that during a one-year period, Americans suffer from one billion colds! Although rhinoviruses and the coronaviruses cause the majority of colds, there are more than 200 viruses that can inflame the membranes in the lining of the nose and throat. (And we probably don’t have to remind you how miserable you feel for anywhere from one to 10 days.)

Despite the billions of dollars that pharmaceutical companies spend on researching a cure for the common cold, the best they have come up with are products that alleviate symptoms—and usually make you feel drowsy. And because children have between six to ten colds each year, while the average adult will get two to four colds a year, it behooves them to keep on truckin’. Sooner or later, a brilliant researcher will come up with a cure that will net Big Pharma zillions of dollars.

Echinacea is one of the first remedies that holistic health care practitioners recommend as both a preventative and therapeutic treatment option for colds and upper respiratory infections—despite negative evidence from poorly designed clinical trials.

How does echinacea work?

Hundreds of scientific studies have been done to determine echinacea’s pharmacology and clinical applications. Researchers have discovered that the three major types of echinacea—echinacea purpurea, E. pallida, and E. angustifolia—contain a diverse range of active components affecting different aspects of immune function. But primarily, echinacea works as an anti-inflammatory, immunostimulant, antibacterial, and vulnerary (wound healer).6

Echinacea’s pharmacological effects

  • Echinacea’s polysaccharide and phytosterol constituents support the immune system by activating white blood cells (lymphocytes and macrophages).7
  • Echinacea promotes nonspecific T-cell activation, a type of white blood cell important in providing resistance to bacteria, yeast, fungi, parasites, and viruses (including herpes simplex, Epstein-Barr, and viruses that cause hepatitis). The T-cells then increase the production of interferon, an important part of the body’s response to viral infections.8
  • Echinacea activates a non-specific immune response via a part of the immune system known as the alternate complement pathway.6
  • Echinacea helps keep tissue healthy, reducing the spread of infectious agents by attacking hyaluronidase. Hyaluronidase is an enzyme that attacks hyaluronic acid—which helps keep tissue intact.6
  • Echinacea exerts a mild cortisone-like effect, which enhances the adrenal cortex hormones. This action appears to be responsible for echinacea’s direct anti-inflammatory activity.6

What’s the difference between the three major types of echinacea?

Echinacea is a very complex compound and the three different species contain different active chemicals, which some researchers suggest act synergistically.9 In other words, all three species have immunostimulatory activity, but since no single bioactive ingredient is responsible for all of echinacea’s actions, and since each species has a slight variation in the amount of each active component, you want to make sure you use a product that contains echinacea purpurea, E. pallida, and E. angustifolia.

For example, the roots and tops of echinacea purpurea and E. angustifolia, as well as the tops of E. pallida, contain alkylamides. But E. purpurea contains cichoric acid, and E. angustifolia contains significantly more echinacoside than the other two. Although these differences are not thought to have much clinical significance on their own again, it’s the synergy of the combinations that may be significant.

Unless you have a background in chemistry, your eyes probably just glazed over. But in a nutshell, here’s the significance of the most important bioconstituents:

Alkylamides have been shown to stimulate the proliferation of alveolar (airway) macrophages. Alkylamides also assist in the production of cytokines—such as TNF alpha and IL-1—which signal other lymphocytes to actively fight off an infection.10

Cichoric acid is a phenolic compound that has been shown to stimulate phagocytosis (viral and bacteria cell destruction).11

Echinacoside accumulates in the roots, but is also found in smaller concentrations in the flowers. It is an anti-inflammatory and seems to enhance wound healing. In one study, the echincoside in E. pallida was found to have stronger anti-inflammatory and wound healing effects than the echinacoside in E. angustifolia, when applied topically to laboratory animals.12

Why the jury is still out

Although numerous echinacea studies have shown clear benefits, its therapeutic effectiveness in the treatment of colds has not been fully established by the scientific community because studies have produced conflicting results for a number of reasons. First of all, it’s important to remember that not all echinacea products are equal. There are a variety of echinacea products on the market with different phytochemical compositions, and flawed studies have had a wide variability in dose and outcome measures.13 14 It’s essential that the right active constituents are identified and standardized. Researchers make a huge mistake when they test an echinacea product without these qualifications.

A paper written by a Kaiser Permanente Medical Group in Denver and recently published in the American Medical Journal points out that researchers who study herbal supplements may be unaware of the extent to which herbal quality control issues may detract from the value of otherwise well-designed clinical trials. After identifying all the randomized controlled trials evaluating single-herb preparations—including echinacea—that were published in English on the National Library of Medicine’s Medline, the authors concluded that “the scientific and clinical utility of future herbal randomized controlled trials would be enhanced if authors provided evidence that the herbal products studied were of high quality.”15

Let’s look at the study published in the New England Journal of Medicine, July 2005, for instance, as an example of what a flawed study is, and then at some well-designed studies.

The flawed study that created a media sensation

The New England Journal of Medicine article concluded that the extracts of echinacea were statistically ineffective in lowering rates of infection or the severity of symptoms of a cold virus. And the media did a fantastic job of smearing echinacea as a reliable herb with powerful benefits.

But—and this is a big BUT—the cold virus was artificially induced using a strain of rhinovirus type 39 in a group of 399 college students. Although a majority of the scientific community acknowledges that the study was performed in a scientific manner by a reputable institute, Wayne Silverman, Chief Administrative Officer for the American Botanical Council, pointed out three main flaws of the study. First, the extracts used in the study were made in a university lab, and they were not comparable to any echinacea products currently sold.16

The product, in fact, used three different extracts from just the roots of echinacea augustifolia, when it’s important to use the three primary species. (See the previous section “How does echinacea work?”)

Even in the published discussion of the study, researchers said, “Given the great variety of echinacea preparations, it will be difficult to provide conclusive evidence that echinacea has no role in the treatment of the common cold.”16

The second problem with the study was the dosage. The dose of echinacea root used was 900 mg per day for seven days before the virus was introduced and then five days afterwards. The study evaluated both preventative and treatment effects of the various echinacea preparations on the infection and found no significant results for either. One important consideration was that the dose was not adjusted for the acute infection phase of the study.

Silverman said, “We believe that with more frequent and higher dosage, the results might have been different. The dosage used in the study was probably one-third of what it should have been.”16

The third problem was that using a group of college students in a sequestered environment would not likely produce the same results as using subjects with weaker immune systems, such as the elderly. The study’s participants most likely had strong immune systems. A better study would have included a cross-section of both young and older people whose immune systems were compromised … showing that echinacea has a greater impact on people with lower immunity.

“Unfortunately,” said Silverman, “the results [of this study] have been extrapolated to mean echinacea is not effective, period. This study should not be used as a reason to think echinacea is not effective at all.”16

Additionally, some health care professionals believe that coverage of the study was biased, since media sources positioned such a poorly designed study as front-page news.16

Well-designed studies support the use of echinacea

The question that comes up, then, is why does the media ignore news pieces on well-designed studies such as the study that appeared in The Journal of Clinical Pharmacy and Therapeutics in 2004, which clinically proved that echinacea significantly reduced the severity and duration of the common cold?

In this randomized, double blind, placebo-controlled study on a standardized echinacea preparation 282 healthy subjects aged 18-65 years with a history of 2 or more colds in the previous year received either echinacea or placebo. They were instructed to start the echinacea or placebo at the onset of the first symptom related to a cold, consuming 10 doses the first day and 4 doses per day on subsequent days for 7 days. The severity of the symptoms and dosing were recorded daily, and a nurse examined the subjects on the mornings of days 3 and 8 of their cold.17

One hundred twenty eight of the subjects got a common cold; 59 took echinacea and 69 took a placebo. The total daily symptom scores were found to be 23.1% lower in the echinacea group, and throughout the treatment period, the response rate to treatments was greater in the echinacea group. The researchers concluded that early intervention with a standardized formulation of echinacea resulted in reduced symptom severity in subjects with naturally acquired upper respiratory tract infection.17

Another clinical trial which took place in a pediatric clinic in Israel studied 430 children who were given either a placebo or an herbal supplement containing echinacea, propolis, and vitamin C. After 12 weeks, there was a 55-60 percent reduction in the number of episodes of respiratory tract infection, the number of days of fever, and episodes found in the group that took the supplement.18

More interesting studies

Researchers at McGill University, Montreal, Canada, investigated the value of taking echinacea intermittently, continuously, or only at the beginning of an illness. All the mice that received a daily dose of echinacea, throughout life, were still alive at seven months, as opposed to the control mice, of which 79% were still alive.

At approximately 13 months of age, the mice that consumed an untreated diet had a 46% survival rate while those consuming echinacea, had a 74% survival rate. Additionally, the key immune cells—natural killer (NK) cells—were significantly elevated in both the bone marrow production site, as well as in the spleen—the major organ to which they traffic and function. The researchers concluded that it appears that regular intake of echinacea may indeed be beneficial/prophylactic, if only for the reason that it maintains an elevated level of NK cells, the most important defense against tumors, a phenomenon which increases in frequency with progressive aging.19

An Italian team of researchers tested an extract obtained from E. angustifolia roots in vitro in mice cells and found that it enhanced immune function by increasing T-lymphocyte cells. In vivo, the extract reduced Candida albicans-induced mortality in normal mice and those treated with cyclosporin A, an immunosuppressant drug.20

How safe is echinacea?

Most of the studies of echinacea have shown it to be a safe herb with very limited side effects. The most commonly reported side effects, which are rare, are gastrointestinal upsets and rashes.21 According to the German Commission, because of its immune stimulating effects, echinacea should not be taken by individuals who have multiple sclerosis, AIDS, tuberculosis, leukemia, and autoimmune disorders such as rheumatoid arthritis and lupus, or by those taking immunosuppressive drugs.

Also, people who have asthma or who are allergic to related plants in the daisy family, including ragweed, chrysanthemums, marigolds, and daisies are more likely to have an allergic reaction than those who do not.

If you are pregnant or lactating, consult your health professional before taking echinacea.

How long should you take echinacea?

This has been a bit controversial, and the debate is still going on as to whether you should take echinacea intermittently, continuously, or only at the beginning of an illness.

One recent study found that daily consumption of echinacea is prophylactic, extending the life span of aging mice and mice with leukemia. The researchers add that, “Given that humans are 97% genetically common with mice and that virtually all our basic physiology is identical, it is neither unjustified to extrapolate these observations to humans nor would it be an arduous task to perform many of these studies in humans, thus establishing viable scientific evidence replacing the anecdotal.”22

Some people take echinacea every day to help enhance their immune systems during the cold and flu season. For those wishing to follow a health maintenance program take 1-2 capsules (450 mg – 900 mgs) a day continuously. For those fighting an immune imbalance, take 3-6 (1,350 mg – 2,700 mg) capsules a day until the illness subsides.

Probably the best advice is to follow the directions on the label, and/or speak with a health professional who is familiar with your personal needs and medical history.


There are plenty of reasons to take echinacea … and if you ask your friends, you’ll find plenty of them who swear by it. There’s overwhelming anecdotal evidence that it works as an immune enhancer, and there are many well-designed clinical studies that have proven its effectiveness in reducing the severity and length of colds and flu. So don’t hesitate to stock up this winter. Start revving up your immune system with the best-selling herb in America so you can avoid the discomforts of the viruses that force millions to miss work and school each year.


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