Botanicals and Herbs: Food or Medicine?

Written records of the use of botanicals, herbs, and spices in medicine and food date back more than 5,000 years (Swerdlow 2000). Even as recently as 1890, 59% of the listings in the U.S. Pharmacopeia were from herbal products (Swerdlow 2000). It has been estimated that as many as one-third to one-half of currently used drugs were originally derived from plants (Barrett et al. 1999). According to the World Health Organization, traditional medicine is characterized by herbal remedies, which are the foundation of the present widespread use of traditional medicine in China, Africa, Europe, Southeast Asia, and North America.

Egyptian schools of herbalists are said to have existed since 3000 B.C. (Penn State Extension 2016). Two of the identified uses of herbs described in oral history are the use of borage (Borago officinalis), administered to those who needed courage, and rosemary (Rosmarinus officinalis), which was given for memory problems. Despite these interesting healthful applications, it is important to remember that borage oil, a source of γ-linolenic acid, also contains pyrrolizidine alkaloids (Wretensjö and Karlberg 2003). The pharmacology of rosemary is considerably more complex; it is based on caffeic acid and its phenolic derivatives (Al-Sereitia et al. 1999). Adverse events associated with rosemary involve allergic reactions and pulmonary distress. These events are rare, however (Barceloux 2008).

A cursory survey of the Internet yields a myriad of articles, blogs, and, of course, marketing and sales websites devoted to botanicals, herbs, herbalism, and herbal medicine. These terms are seen in discussions of Ayurvedic, traditional Chinese medicine, and traditional African medicine and seem consubstantial with declarations of fresh air, rest, and proper diet as the basis for achieving and maintaining health and treating a vast spectrum of diseases. Recurrent themes include the “Doctrine of Signatures,” which suggests that the physical appearance of an herb is indicative of therapeutic use; the notion that plants grown in a certain area tend to cure the diseases afflicting that region; the idea that herbs are “holistic;” and the position that the various whole plant extracts in herbal medicines are superior to the single pure component of a drug since the multiple ingredients enhance therapeutic effect and limit side effects.

Throughout world markets, including those in developing countries, species of medicinal plants appear to be playing an increasingly important role; they are abundant, locally available, relatively inexpensive, and consistently associated with safety and efficacy (George 2011). According to a 2008 consumer assessment of herbal product usage, herbal products have gained popularity in recent times and even 10 years ago were used by approximately 20% of the population (Bent 2008).

There seem to be almost as many definitions of these apparently simple plant-related terms as there are examples of the plants that they are purported to describe. Ingredients characterized as botanical or herbal appear in teas, foods, tinctures, oils, extracts, syrups, tablets, lozenges, creams, salves, lotions, and poultices.

The dose and form of a botanical preparation play important roles in its safety. Teas, tinctures, and extracts have very different strengths. The same amount of a botanical may be contained in a cup of tea, a few teaspoons of tincture, or an even smaller quantity of an extract. Each botanical or herb may contain any stable or variable combination and dose of dozens of compounds such as fatty acids, sterols, alkaloids, flavonoids, glycosides, saponins, and others (Rotblatt and Ziment 2002).

Herbs are often perceived as natural and therefore safe, despite the fact that many different side effects have been reported, likely related to varying, unknown, or unstudied active ingredients, contaminants, or interactions with drugs (Bent 2008). Particularly concerning is that the true frequency of side effects for most herbs is not known because most have simply not been tested in large clinical trials and because surveillance systems and compendia of classification such as the German Commission E reports are much less extensive or scientifically substantive than similar works that exist for pharmaceutical products (Blumenthal et al. 1998).

With all due respect to practitioners and well-intended consumers, the best of intentions along with an uncritical view of what botanicals and herbs are or are not and a failure to utilize scientific rigor in anticipating unintended negative consequences of our good intentions may provide a foundation for significant public health concerns. As scientists, we must approach botanicals and herbal-based products with a critical eye, and only on the basis of carefully developed and analyzed data can we consider the safety and efficacy of these products.

 

Roger Clemens, DrPH, CFS, Contributing Editor
Adjunct Professor, Univ. of Southern California School of Pharmacy, Los Angeles, Calif.
[email protected]