Herbal and Botanical Dietary Supplements

Historic and anecdotal information and scientific data suggest that herbal and botanical dietary supplements have a high level of biologic activity and, in many cases, act as medicines. Despite their widespread use over time, however, scientific evidence supporting their efficacy and safety is lacking. Nevertheless, many herbal remedies are among the most popular dietary supplements purchased and used regularly in the United States. Table 4.4 lists some of these herbal and
botanical dietary supplements, but the information is by no means all-inclusive.
Based on historic uses, several assumptions have been made regarding herbal and botanical dietary supplements, despite a lack of scientific evidence. For example, ginseng (Panax ginseng), which can have an unusual and almost human appearance, is recommended for common ailments such as lack of energy, lagging libido, and a poor immune system.
In addition, many herbal and botanical dietary supplements are promoted for uses that are unsupported or have been disproved. Comfrey (Symphytum officinale) has been and continues to be used for a variety of conditions associated with inflammation, including diseases of the gastrointestinal and respiratory system. No evidence supports these uses, however, and comfrey is among the herbal and botanical dietary supplements currently considered extremely dangerous. Another very popular herbal remedy, echinacea (Echinacea purpurea, Echinacea angustifolia), has been shown in three scientific studies to be ineffective at preventing or decreasing the severity of the common cold.
Perhaps the most common assumption about herbal and botanical dietary supplements is that one name refers to one "herbal medicine." In truth, there are so many common names and parts of various plants that are used that it is sometimes impossible to identify exactly what is encapsulated in an herbal or botanical dietary supplement. Kelp, which is used in folk medicine to treat constipation, bronchitis, emphysema, asthma, indigestion, ulcers, colitis, gallstones, obesity, and genitourinary and reproductive abnormalities in both men and women, actually refers to a huge family of seaweeds and algae. It is extremely difficult to evaluate the efficacy of a substance whose origin cannot be identified.