From selenium for cancer, to vitamin D for diabetes, to fish oil capsules for high blood pressure, more and more people are turning to dietary supplements to prevent and treat all sorts of health woes (1–3). Upper respiratory tract infections (URTIs) such as the common cold, which affect the pharynx (throat), larynx (voice box), sinuses, or nose, are certainly no exception (4–5).
To treat or prevent URTIs many people are flocking to echinacea, a group of North American wildflowers belonging to the daisy family (4;6-9). Three species in particular—E. angustifolia, E. purpurea, and E. pallida—are used for medicinal purposes. Echinacea products vary in the combination of species they contain (4), the part of the plant they use (i.e., the entire plant, versus the root, flower, stem, or leaves), how the medicinal compounds are extracted, and whether other natural components are included (10). They also come in many forms, such as capsules and tablets, juices, teas, extracts, drops, and powders (4).
Just how many people are on the echinacea bandwagon? With annual sales in the U.S. ranging from $10–100 million, it’s safe to say…“a lot.” Given this dedicated fan base, you may be surprised to learn that echinacea’s safety and effectiveness are still up for debate (4;11–16). One recent systematic review weighed in on the discussion, specifically looking at whether echinacea can prevent or treat URTIs (4).
What the research tells us
The review compared people using echinacea in a variety of doses and forms (e.g., capsules, juices, and more) to people using a placebo such as vegetable oil, beeswax, herb powder, or chocolate-flavoured syrup. The review found that echinacea had a small effect, reducing the chances of developing a URTI by 12%–22%. In contrast, echinacea had no effect on how long a URTI lasted once an infection had taken hold.
It’s worth noting that the studies included in the review were not always of high quality, and there were large differences in how they were conducted. This makes it difficult to pinpoint the type of echinacea products to recommend and how much to take. Variation in how echinacea products are prepared and how people use them could also affect how well echinacea works in the real world, outside of a research setting. Fortunately, short-term use of echinacea doesn’t appear to come with an increased risk of negative side effects, but more research is needed into how safe these products are if used long-term (4).
So, does echinacea deserve a spot in your medicine cabinet? Ultimately, folks should keep in mind that it’s important to weigh echinacea’s limited benefits against the uncertainty around its long-term safety. As with any other supplement, in addition to doing your own research, make sure to consult with your health care provider to understand how echinacea might interact with any existing health conditions or other medications and supplements you are taking, as well as any other potential risks with its use.
DISCLAIMER: Given the current situation around COVID-19, it’s important to note that none of the studies included in the review looked at COVID-19 specifically and should not be used to guide actions to reduce your risk of COVID-19. In order to reduce your risk of contracting and spreading COVID-19 and other respiratory illnesses, please follow current public health guidelines including physical distancing, proper hygiene (e.g., handwashing, not touching your face, covering coughs or sneezes, cleaning surfaces), limiting travel, and more. Learn about these guidelines in detail via the Government of Canada’s website: https://www.canada.ca/en/public-health/services/diseases/2019-novel-coronavirus-infection/prevention-risks.html.
