Echinacea: What Makes This Plant So Interesting?

1. What Is It Actually?

The purple coneflower has the scientific name Echinacea purpurea. Plants are small factories. They build their own substances from water, light and air. Such substances are called natural products. Yet the purple coneflower does not make only one single substance, but many different ones at once. It is like a soup: many ingredients swim together in the pot, and no single ingredient tastes like the whole soup. Researchers call such a mixture, for example, an extract. With a plant it is also important which part one takes. In studies with humans the root of the purple coneflower was sometimes examined. Sometimes preparations from the fresh parts of the plant were examined. These are not the same mixtures. A study with the root can therefore show something different from one with the fresh parts. So when you read “purple coneflower helps”, the most important question is always missing: which part? And how was it prepared? Natural products are, by the way, not an invention of humans. They have been there since plants existed. We have only learned to notice them.

2. Where Does It Come From?

With a plant the question is easy to answer: it comes from the plant itself. But from which part? That varies. In studies with humans, for example, an extract from the root was tested. An extract is a liquid in which the plant substances have collected – similar to making tea, only done more precisely. In other studies preparations from the fresh plant were examined. Still others used a liquid extract that remains liquid. Root, fresh plant, liquid extract: these are three different things. They smell different, they taste different, and they do not contain exactly the same substances. A researcher therefore never simply says: “I tested purple coneflower.” He states exactly which part he took and how he prepared it. Only then can another researcher repeat the study and check whether he finds the same thing.

3. What Do the Researchers Examine?

There are many papers on the purple coneflower. In total there are 195. In 69 of them humans were examined. 41 of these 69 were controlled. Controlled means: one group of people received the preparation, another group received something that looked the same but contained no plant substances. This way researchers can see whether a difference really comes from the plant. In these studies the focus was mostly on colds and the respiratory tract. One paper looked at children with an upper-respiratory-tract infection. Others asked: do people fall ill less often? Does a cold run a milder course? Another paper examined whether the purple coneflower together with other substances changes something in the body. With so many papers new questions arise: which plant part is the right one? How must it be prepared? And do some people react differently from others? These questions are still open, and researchers continue to work on them.

4. A Thought Experiment

Imagine you want to know whether a plant juice helps with a cold. Your friend says: “I drank it, and three days later I was well again!” Sounds good, doesn’t it? But a cold gets better after a few days anyway – even without the juice. Now comes the interesting question: how would you find that out? For example like this: you look for many people who caught a cold on the same day. One half receives the juice. The other half receives a liquid that looks and tastes the same but contains no plant substances. Nobody knows who receives what. Afterwards you compare both groups. That is exactly how researchers do it. It is a trick to avoid deceiving oneself.

For adults and professionals: the detailed page on purple coneflower (Echinacea purpurea).