New book explains plants as medicines

Letting readers 'decide for themselves'

A new book by botanists at Washington University in St. Louis enlightens both consumers of natural products and herbs and traditional physicians.

Medical Botany, Plants Affecting Human Health, is the second edition of a 1977 book, Medical Botany, published by Walter Lewis, Ph.D., professor emeritus of biology, and Memory Elvin-Lewis, Ph.D., professor of microbiology and ethnobotany in biomedicine in Arts & Sciences at Washington University. John Wiley & Sons, Inc. has just published the 812-page book. The book clarifies and classifies the role that plants and herbs play in human health. The work can be a cornerstone of an individual’s research and practice in this area, whether it be parsing the properties of Echinacea or St. John’s wort, or learning the calcium content in black beans, or the medicinal value of garlic and red wine.

Memory Elvin-Lewis and Walter Lewis, authors of *Medical Botany*, examine *Ehretia* in the Jeanette Goldfarb Plant Growth Facility at Washington University in St. Louis. Ehretia is a West African plant that indigenous people make into a poultice to treat bone injuries.

The book is a cornucopia of information on the benefits of plants, herbs, vitamins, minerals and dental plants as well as the dangers of ingesting certain plants or combining a certain herbal therapy —as one example, flaxseed oil — with conventional treatments — blood thinners — which can put people at risk of developing hemorrhagic stroke. There are countless such descriptions. There are lightly written sidebars in each chapter, extolling the healthy properties of soybeans, for instance, or the good news about chocolate’s benefits. Part I consists of three chapters on injurious plants, including a very long table describing the symptoms of plant poisoning complete with antidotes. There are twelve chapters in Part II that look at every conceivable part of the human body and mind as they relate to plant and herbal treatments, including plants that affect metabolism and the gastrointestinal tract, plants as they relate to cancer, and a thorough table describing every known and documented plant or herbal aphrodisiac. Part III is composed of four chapters on psychoactive plants, dealing with stimulants, hallucinogens and depressants.

For 20 years, the couple has worked with native Amazonian indigenous people in identifying and classifying their uses of plants for a variety of medical uses. They note that the Jivaro Indians of Peru alone use at least 500 species of plants for medicines on a daily basis. Also, they mention that Navajo apprentice healers must learn the medicinal uses of nearly 200 plants; Samoan healers apply between 100 and 200 plant and herb species; and they note that traditional medicine in China, which includes herbal medicine and acupuncture, is being incorporated in varying degrees with conventional medicine.

Elvin-Lewis said that Western physicians generally have little understanding of herbalism, not to mention self-medicating patients, many of whom also take traditional or “newly evolved” herbal medicines. “There still is an uncertainty in the medical community about the value of herbalism, despite the fact that herbs are very much mainstream,” said Elvin-Lewis, a fellow of the International Society of Herbal Medicine in India.

Non-traditional herbal meds can be ‘dicey’

According to Elvin-Lewis, when compounded and prescribed appropriately, the safety of traditional herbal medications is high. It is generally recognized that life-threatening events are rare, when compared to the hundreds of thousands of adverse reactions reported for pharmaceutical products. However, with herbal remedies, in particular, adverse problems are unlikely to be reported because there is often a preconceived notion that the herbs are not harmful.

The authors state that uninformed use of non-traditional plant remedies can be dicey to a person’s health. They note instances of hallucinations with cinnamon and tetracycline, sedative effects with Valerian or passion flower and antihistamines, elevated blood pressure with thizidine diuretic and Ginko biloba, and increased seizures when evening primrose is taken in addition to phenothiazines, active ingredients in a number of pharmaceuticals.

And if you’re going herbal to lose those 15 extra holiday pounds, the book makes clear that you should avoid sparteine-containing herbal treatments for slimming and diabetes control. The authors say that these treatments have been associated with instances of circulatory collapse, respiratory arrest and nerve irregularities. Blossoms of germander in herbal teas or capsules to treat obesity have been shown to cause acute hepatitis. Instances of kidney failure have been found in Japan, China and the United Kingdom in people using various herbal slimming agents.

“We believe that anyone considering taking herbal medications must be well-informed and not rely on unfounded claims found in other-than-scientific literature,” Elvin-Lewis said. “Our book lets readers decide for themselves.”

Lewis said their work reflects the fact that plants are an essential of life.

“Plants feed us, protect us and provide us with medications,” he said. “They are a key component of the fabric of life and are a major part of human history. That’s all reflected in the book.”