‘Medicinal’ plants? The supposed benefits of propolis, echinacea and other herbs

Infusions, supplements and even chocolates promise to help you lose weight, sleep better or boost your immune system, thanks to the presence of certain plants or natural compounds. Do they really work?

Do herbal infusions really have an effect on health?
Do herbal infusions really have an effect on health?PXHERE
Beatriz Robles

“For constipation,” “for stomach pain,” “for sexual stamina”: who hasn’t noticed the stands of herbal remedies that offer an efficient solution for every health problem? You begin asking about something for knee pain, and you end up discussing all of your physical afflictions. Without any control or consumer regulations, the seller’s eloquence is enough to convince you to take home not just one, but several bags of herbs.

To be clear, I respect herbal medicine. Vegetables offer compounds that, in controlled doses, have concrete biological effects, and, in fact, extracted from the plants or synthesized in the laboratory, form the basis for many medications. But those meticulously calculated formulas are far from the haphazard uses of plants that may have the same compounds, but in unknown concentrations, according to the stress that the plant may have suffered, its growth conditions, the soil, the water, the moment of harvesting and many other factors.

Magic in the supermarket

Such claims can be found in the supermarket. You won’t see herbs stacked on shelves, but you will find them in more subtle and refined presentations, developed by marketing and R&D departments that can convert anything into a product to fix the problems you didn’t know you had.

Compounds with apparent health benefits appear on almost any type of product. Sophisticated herbal teas feature little-known ingredients and statements about their properties, from the discreet “relaxing” to the more aggressive “fat burner.” A range of magical foods purport to solve complex health problems.

If a product has a photo like this, run away.
If a product has a photo like this, run away.PETR KRATOCHVIL (PUBLIC DOMAIN PICTURES)

Here’s what science says about the properties of some of these magical foods.


It is supposedly the key to not having colds all winter. Some products claim that the herb improves natural defenses, among other properties. A review by Cochrane, a prestigious scientific database, concluded that it has not shown benefits to treat colds and that any positive effect is not clinically relevant. We apologize to those who bought this tea.


It is not a botanical compound, but a material made by bees to build their hives. It is alleged to “help the upper respiratory tract” or “help during cold season,” which in many cases is reinterpreted as “improving defenses.” According to Medline, it could be effective for treating inflammation and mouth sores in certain cases: when sores are caused by cancer treatment drugs and when consumed orally or in rinses.

Green tea does not work miracles.
Green tea does not work miracles.TANG DON (UNSPLASH)


The king of diuretic products also claims to help keep hair and nails in pristine condition. According to Medline, however, there is not enough reliable information to discern whether it is useful.

Green tea

The supposedly infallible ally for weight loss is also purported to improve circulation. The National Center for Complementary and Integrative Health, part of the United States’ National Institute of Health, indicates that “despite the fact that many studies have been done on green tea and its extracts, there are no conclusions about whether or not it is useful for the multiple objectives for which it is used.”


Another supposed tool to control weight and “activate fat metabolism,” it is also said to improve immunity, suppress hunger and eliminate fatigue. The latter could be thanks to the effect of caffeine. According to Medline, “although there is interest in using guarana for many purposes, there is not enough reliable information to know if it is useful.”

Ginkgo biloba

It is alleged to help maintain mental well-being, memory and cognitive function. The National Center for Complementary and Integrative Health indicates that there is no conclusive evidence that it is useful for any health condition. We hope the tea at least tastes good.

Beyond infusions

Plant extracts are also freely marketed in formats such as pills, tablets, ampules, powders and similar forms. Although they boast of health properties, they are not considered medicines, which would place them under severe marketing restrictions, but dietary supplements, so food regulations apply to them. This is not without controversy: unlike supplements, drugs have to improve, correct or modify physiological functions. Some products may be classified as a dietary supplement in one country and a medicine in another.

Mint doesn't do much either, but it's very tasty.
Mint doesn't do much either, but it's very tasty.PXHERE

These days, medicinal plants appear in the very last foods where you’d expect to find them, like a chocolate bar whose content is 25% sugar. They create a fantasy that solves the eternal consumer dichotomy: we are crazy about ultra-sugary and ultra-processed foods, but we know that they’re not the best for our health. Voilà: incorporate an ingredient with healthy properties, and it compensates for all the negative properties.

Statements such as “helps your defenses” or “contributes to normal psychological function” are health claims. In Europe, they must be authorized in order to be displayed. These claims are made based on the presence of isolated nutrients or ingredients, such as vitamins, minerals and fiber. If a type of food has a certain amount of vitamin B6, you can say that it helps your defenses, it contributes to your psychological function and reduces tiredness and fatigue.

But regulations have some important caveats. That’s why we see iron-enriched cakes that “contribute to the cognitive development of children.” Thousands of such statements swarm with impunity in food supplements and foods, thanks to the difficulty of evaluating these supposed properties.

As explained in a Science Direct study, testing the benefits of many nutrients is relatively easy. In fact, many of them do not have spectacular benefits, but are simply necessary for physiological functions. In the case of botanical compounds, proving clear health effects is much more complicated.

What can we do to avoid being gypped by such claims? Know the game. If a label draws your attention to a particular ingredient and makes promises that sound too good to be true, leave it out of the cart. It’s using magical thinking to condition your food choices. The foods that will help you, such as fruits, vegetables, legumes or nuts, do not come with bombastic claims.

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