Many botanicals are well known to have a variety of health benefits. These benefits are often due to the secondary plant metabolites they contain. These are compounds that are not involved in the plant’s primary metabolism (i.e., the processes that are essential to the plant’s survival). Instead, they are formed in response to the plant’s environment (e.g., when the plant is injured).

One of the most famous secondary plant metabolites may be allicin, which is formed in garlic from alliin when the bulb is cut or crushed. The typical garlic smell, due to the presence of allicin, is the plant’s defense against being eaten. Allicin famously supports cardiovascular health by reducing cholesterol levels. Garlic also contains other secondary metabolites that have other health benefits, but allicin is the best known one.

Recent research confirms that another group of secondary metabolites, phenolic compounds such as polyphenols, function not only as antioxidants but also as prebiotics, which means they nourish beneficial gut microbes while suppressing harmful ones, thereby influencing overall health through the gut microbiome. In a clinical trial published in the European Journal of Nutrition in 2017, phenolic compounds from virgin olive oil positively influenced LDL blood concentrations, which might be mediated by increases in populations of bifidobacteria.

Other examples for specific plant-derived compounds that promote beneficial gut bacteria and inhibit those linked to negative health outcomes are bromelain from pineapple as well as astragalus and bergamot extracts.

Research is also uncovering the potential of more botanicals in the area of mental health and cognitive function. In this category, ginseng and ginkgo are well-known and well-established examples. Clinical trials have now shown that peppermint tea can have positive short-term effects on cognition and cerebrovascular function.

Generally, the scientific approach to botanical research has been evolving for a while from traditional ethnobotanical use toward rigorous methods, including clinical trials, mechanism-of-action analyses, and omics technologies like genomics and metabolomics, which provide deeper insights into how botanicals influence specific biological pathways. This shift is validating the use of botanicals for conditions ranging from gastrointestinal disorders and urinary tract infections to psychosomatic issues, with positive outcomes reported in many studies, although the quality and consistency of evidence vary across indications.

This is also one of the persistent criticisms of botanical ingredients. Unlike chemical actives whose quality is consistent, botanicals are subject to crop and batch variations, but also changing environmental conditions that influence the contents of beneficial compounds. This necessitates standardization, but it also influences the results of clinical trials. As a consequence, the level of evidence for clinical trials on botanicals, with some notable exceptions where a plethora of data exists, is generally regarded to be not very high.

Still, consumers have always demanded “natural alternatives” to chemical drugs for treatment of non-communicable and not life-threatening diseases, and at least in Europe, the market obliges. Of course, the problem with botanicals in food supplements in the EU lies in what you can or cannot claim on the label. Currently, health claims relating to botanicals are in a regulatory gray zone, and regulators are instantly on alert whenever they find one of them on a label, which may result in close scrutiny of the product in question.

If companies want to market a botanical and make use of one of the pending botanical claims, regulatory consultancies such as a&r gmbH generally recommend preparing a dossier with evidence for the claim that can be produced upon request, even though it is not mandatory for food supplements to have such a dossier.

It will be interesting to see how the health claims situation for botanicals continues to develop in the EU. One can only hope that the many health benefits that are being uncovered by science can one day also be communicated to consumers.

About the Author: Dr. Joerg Gruenwald is co-founder of analyze & realize GmbH, a specialized business consulting company and CRO in the fields of nutraceuticals, dietary supplements, herbals and functional food, and author of the PDR for Herbal Medicines. He can be reached at analyze & realize GmbH, Waldseeweg 6, 13467 Berlin, Germany; +49-30-40008100, Fax: +49-30-40008500; e-mail: jgruenwald@a-r.com, www.analyze-realize.com