Are Medicinal Plants and Herbs Poisonous?
"Many people believe that because medicines are herbal (natural) or traditional, they are safe (or carry no risk for harm). However, traditional medicines and practices can cause harmful, adverse reactions, if the product or therapy is of poor quality, or it is taken inappropriately or in conjunction with other medicines." — World Health Organization (WHO)
My brother had a regular customer who patronized his eatery every day to socialize with friends. A market seller, he retired after having made a fortune in the stock market, when he successfully cashed in during the 1997 Asian Financial Crisis.
Planning to keep himself healthy so as to prolong his life and enjoy his wealth, he consumed a lot of so-called "health products", bought from a highly reputable health-product network-marketing company (name withheld), but died some 2 years later. Did these products kill him?
Misconception About Herbalism
Herbalism is a traditional medicinal practice, based on the use of plants and plant extracts. Just because these substances are 100% natural, many people are under the misconception that they have no major side-effects. Nothing can be further than the truth, as the next section, "The Nature of Medicinal Plants and Herbs", clearly shows.
Ancient Alternatives: TCM and Herbal Side Effects
Aloe Vera Side Effects
Ginseng, for example, has traditionally been touted and prized by the Chinese as a cure for a number of medical conditions. Medscape.com says:
"In 1979, the term "ginseng abuse syndrome" was coined, as a result of a study of 133 people who took ginseng for 1 month... At a dose of more than 15 g/d, some subjects experienced depression. Fourteen patients experienced ginseng abuse syndrome, which is characterized by symptoms of hypertension, nervousness, sleeplessness, skin eruption, and morning diarrhea... Vaginal bleeding has also been reported in cases related to ginseng use."
As another example, Aloe Vera is widely used in the traditional herbal medicine of many countries. In Ayurvedic medicine, it is used as a multipurpose skin treatment, partly because it contains saponin, an anti-microbial agent. As the video on the right, "Aloe Vera Side Effects", clearly says, "Any issues associated with Aloe Vera usually only occur as a result of excessive intake..."
There is clearly a limit as to how much herbal medicine one can consume, as the graph on the right shows. Anything in excess can be detrimental or even fatal, due to toxicity.
The Nature of Medicinal Plants and Herbs
All medicinal plants and herbs produce 2 kinds of metabolites:
- Primary metabolites, which are substances such as carbohydrates, proteins, and fats that are necessary for normal growth, development, and reproduction.
- Secondary metabolites, which are substances that help plants defend themselves against attack from a wide variety of predators, such as insects, fungi, and herbivorous mammals. While these substances are toxic to plant predators, they may be capable of treating human diseases.
Plants, by the way, are not philanthropists in that they do not produce secondary metabolites for the expressed purpose of benefiting human beings. If these substances have any beneficial benefits to mankind, it's purely incidental. Does this make sense to you?
Medicinal plants and herbs have been used in Traditional Chinese Medicine and Indian ayurvedic medicine for a very long time. Being substances that help them to defend against attack from predators, secondary metabolites are essentially toxic in nature. The Chinese has a saying, 以毒抗毒, meaning "using poison to counter poison." If you understand this concept, then the question, "Are medicinal plants and herbs poisonous?", as well as the associated question as to whether overdosage is harmful, becomes crystal clear.
So Is Herbalism Really Effective?
In recent years, the search for drugs and dietary supplements derived from plants has increased dramatically. Many of the herbs and spices used by humans in cuisines yield useful medicinal compounds. Such use of herbs and spices to season food developed, in part, as a response to the threat of food-borne pathogens. Studies have shown that recipes in tropical climates are the most highly spiced. Due to the abundance of pathogens in these climates, the tendency is to use spices that have the most potent antimicrobial activity. Because vegetables are more resistant to spoilage, they are generally spiced less than meat In all cultures.
According to the World Health Organization, some 25% of modern drugs in the United States are derived from plants. A research, carried out in 2001, found that 122 compounds used in mainstream medicine were derived from plants. Of these, 80% were used in the same or similar manner as in traditional medicine. Thus far, at least 12,000 secondary metabolites have been isolated, a number that is said to be less than 10% of the total. Notwithstanding, most of these are derivatives of a few basic biochemical structures.
Most modern herbalists concede that in emergencies where time is of the essence, e.g. heart attacks, pharmaceuticals are more effective. However, they contend that herbs are more superior over the long term in that they can provide nutritional and immunological support in a way that pharmaceuticals cannot. Herbalists view their goal as prevention, as well as cure.
Dosage, however, is, in general, an outstanding issue for herbal treatments. From a pharmacological perspective, herbal medicines taken in whole form generally cannot guarantee a consistent dosage or drug quality, since different specimens of even the same plant species may vary in chemical content.
While pharmaceutical medicine prefers the use of single ingredients because the dosage can be more easily quantified, herbalists, on the other hand, argue that the different phytochemicals in herbs do interact among themselves to enhance the therapeutic effects of the herb and dilute toxicity. They also reject the idea that herbal synergism can be duplicated with synthetic chemicals, claiming that trace components may alter the drug response. In specific cases, these claims of synergy and multi-functionality have been supported by science. However, the question remains as to how widely these specific cases can be generalized.