The nature of herbs

There are a million kinds of plants, and humans have named just about every one of them. Yet, we have been able to focus attention on a small fraction that suit our needs. A few hundred are collected or cultivated in huge amounts for food, building materials, clothing, and other common applications. By far, the greatest number of plants for any use other than gardening (flowers, greenery, shade, etc) has been to aid human health. Worldwide, about 50,000 species of plants have been adopted as medicines. Still, only a fraction of them are relied upon in large quantity. For example, in the practice of European herbal medicine there are about 300 species that were in common use during the 20th century, of which 175 were depicted in Künzle's Comprehensive Guide to Herbal Healing; about 100 of those were used frequently.

This trend toward focusing on a small number of herbs is based, in part, on the work of a few herbal practitioners and scholars who devoted considerable time to the investigation of individual species of interest. In order for an herb to enter into regular usage, it has to have been described with sufficient accuracy-and enthusiasm-that subsequent generations can rely on what has been reported. Over time, plants with powerful effects that are too difficult to control are eliminated from routine use and described as toxic. When two herbs have similar therapeutic uses, one may be retained over the other for reasons of easier access to the medicinal material. Some herbs thought to have remarkable benefits turn out to rarely produce the effect described earlier, and are dropped. Attention is turned to making the best of those that remain.

Once an herb has been deemed reliable in beneficial effect, safe for virtually all users, and able to be found when needed, the next task is to make sure that those in future generations are able to obtain the correct materials. This has been one of the primary roles of the great herbals, especially the illustrated herbals. Still, different plants may have gross features that are similar, and herbs described in the herbals may go by numerous names, generating considerable confusion, which has limited the development of herbalism. It was easy for errors to be introduced and for remedies to go wrong.

We are fortunate that a systematic means of describing plants and naming them has emerged. In relation to the requirements for understanding medicinal plants, botanists subdivide the plants by family, then subdivide the family by genus, and genus by species (sometimes further, by variety). Plant families are marked by having similarities in their general structures; hence, the Pinaceae includes a wide variety of evergreen trees and shrubs with tight leaves, and the Asteracea have showy flowers and includes daisies, dandelions, sunflowers, and many other garden flowers and weeds. The genus links plants that form natural groupings with more similar features. Within a genus, the plants may look similar; sometimes even botanists can easily mistake two species of the same genus due to natural variability in the way the plant grows. Therefore, they must examine the detailed structure of the plant leaves, the flowers (if present), and vascular system to place a plant within one species or another. Microscopic examination may give the requisite information, revealing fibrous structural components and storage cells.

This system of differentiating plants and naming them was given to us by the Swedish scientist Carl Linnaeus (1707-1778) and it has been a tremendous benefit to herbalists. It was not fully utilized until the end of the 19th century, at which point all the European medicinal herbs were identified by these botanical names.

Today, we can specify the botanical name of a plant and it will have the same meaning everywhere in the world. The clinical experiences with using a single species or two closely related species of the same genus in entirely different cultures can now be directly compared. Some herbs have been used not only in Europe, but by the natives of America, by the Chinese, the Africans, and others. The combined knowledge of the herbs from different cultures can be a powerful tool in understanding their potential applications. Modern laboratory and clinical evaluations only make sense when the botanical species under study is clearly identified.

Most herbs have one or two main applications even though they may have dozens of minor uses. We understand that the primary uses of the herb are the direct result of particular groups of active constituents (e.g., terpenes, alkaloids, flavonoids, etc.). Each plant contains thousands of biochemicals, but most of them are either physiologically inactive (or of little activity) or are present in such small amounts as to have no significant effect (unless isolated in high concentration). Fragrant herbs frequently owe their action to the volatile oils that give them their fragrance. Bitter herbs frequently owe their action to alkaloids, saponins, or flavonoids that contribute bitterness.

Yet, unlike isolated chemicals used as drugs, herbal remedies often rely on numerous active ingredients from one or more plant materials that may have a general effect on the body, such as improving digestion or purifying the blood. Promoting digestive functions and relieving digestive distress is one of the central components of herbal healing across the globe because of the long-held belief in the role of diet and the importance of transforming the foods consumed into useful essences for the body. The role of blood purification is particularly important to the European tradition, where it was considered that accumulations of toxic materials in the blood could make the body susceptible to numerous diseases.

Several different plants would be considered of use in treating such conditions and would be combined together. The principles of formulation are diverse, and could depend on the nature of the plant materials themselves, their claimed effect in the body, or some combination thereof.

As an example, Father Künzle described the following unnamed, but easily recognized, medical condition to which he also presented a unique herbal cure: "Many persons are permanently indisposed without really being confined to bed. Lack of appetite makes them refuse even the best sausage [a treat desired by most people]. They suffer from obstinate constipation, have pressure on the chest and stomach, and their head aches and seems on fire. They rarely find sleep, and when they do, it is troubled with bad dreams or nightmares. They consult many physicians and annoy them to exasperation. They reel and totter like a victorious party leader after celebrating an election. They put forth a piteous wail of lamentation like organ pipes, often with a full orchestra into the bargain."

While this colorful explanation may not fit a particular disease recognized today, most health practitioners will sense that he was describing something akin to what is often seen today. According to Künzle: "Such people ought to take a so-called 'spring cure' for a week or a fortnight [two weeks] if they seriously wish to recover. They should send Tony and Jack out to the nearest brushwood with a basket and knife and let them cut as many sprigs as possible from all the thorny bushes that can be found: rosethorn, blackthorn, whitethorn, common barberry, shoots of blackberries, raspberries, pines, beeches, hazels, cherry trees, oaks, larches, ashes, and poplars. Shoots of currants, gooseberries, and fruit trees may be added. Put a handful of this mixture in a pan with two liters of water and let it boil. Add sugar and make your patient drink one or two liters of this tea daily. It cleans and purifies the whole body. It will restore health of persons who really are pitifully ill....The grave-digger can put his shovel back in the shed...."

I have no idea if this spring cure, formulated randomly from spiked sprigs and other branches and shoots as available at the locale, really works, but I must admit it sounds good to me. It is likely that these plants have little toxicity. Natural products specialists will note immediately that the list of ingredients Künzle has proposed is going to be rich in phenolic compounds, mainly flavonoids (including tannins found in the bark of branches and stems). These are understood today to be one of the most interesting groups of herbal compounds because of their low toxicity and wide ranging therapeutic potential. Included among their actions are inhibiting viral infections, reducing allergy reactions, enhancing capillary integrity, and substantial antioxidant effects. Perhaps this would take care of some of the ailing patients. Today, similar flavonoids from pine bark, grape seeds, and other sources are claimed to have remarkable benefits for those troubled by erratic complaints.

The property attributed to these spiked sprigs by herbalists is a blood purifier. This term is sometimes rendered as alterative, implying that the use of the herbs gradually leads one towards a healthier state: altering the body from sick condition to a healthy one. Such terms are still relayed from earlier books, but they are sufficiently vague that they don't inform one about the herbs' activities in the modern context. At the time Künzle was working, blood purifiers were often diuretics that purged out toxins via the urine. Today, it is common for herbalists to speak of them as stimulants to the liver's enzymatic detoxification system. If someone takes an herb or herb formula and gets better, doesn't that really mean that it served as an alterative, regardless of whether the herb has been so designated? And if illness is perceived to be a matter of impure blood, then anything that helps will serve as a blood purifier. So, the definitions may remain unclear, but a reflection of the overall functions of the herbs.

Due to progress in chemistry, an investigative method first applied to herbal medicine during the 19th century, it is often possible to identify very precisely the components of an herb that are responsible for the effects that have long been described by herbalists. Frequently, the chemical analysis is accompanied by laboratory experiments-pharmacology studies-that confirm the connection between an herb ingredient and a specific type of effect. The active constituent, after being isolated from the rest of the plant, is tested in laboratory animals to confirm (or deny) that it produces an effect related to the claimed benefit of the whole herb. It is rare that a carefully controlled clinical trial is performed with herbs, due to numerous factors that make such tests expensive, time consuming, and subject to easy criticism.

Plants are like warehouses of hundreds of chemicals, and it is of little value to list off all the types of substances present, as is sometimes done in herb guides. Surely, an herb may contain essential oils, fixed oils, tannins, flavonoids, alkaloids, sterols, glycosides, and the rest of the list (including virtually all vitamins, amino acids, and other substances common to all plants). Instead, one must identify the materials that are present in sufficient quantity to produce an effect that has been described by herbalists when the herb is given in the usual dosage. In many cases, a single main active constituent or group of constituents of similar nature can be found. For example, anise seed contains a relatively large amount of essential oil (still only a few percent of the whole herb material), which is believed to be responsible for most of the proclaimed benefits of using the herb. Over 90% of its essential oil is one chemical constituent: anethole. Thus, whatever the laboratory researchers can find out about anethole will pretty much describe what this herb does as a crude product. A single constituent can certainly have more than one effect on the body, but it is usually the case that there will only be two or three significant actions of any biochemical. Some herbs have more than one major active constituent, and two (or more) of these constituents may contribute to each of the various therapeutic actions ascribed to the herb.

All herbs, no matter how valuable to health, have the potential for adverse effects, at least in some individuals, or in some manner of use. Some people may develop an allergy to one or more constituents of a plant, and others may simply have some hypersensitivity or intolerance to a constituent (yielding an unpredictable, idiosyncratic response). At some dosage, if one takes enough, the herb may become toxic to the body or, at the least, cause an undesired reaction (such as nausea, vomiting, diarrhea, or headache). If an herb is taken in a moderately high dosage, not enough to cause an adverse reaction immediately, prolonged ingestion of it might still cause effects that are detrimental in rare instances. Some active constituents may accumulate over time if the amount consumed is sufficient to overwhelm the rate of elimination.

It is important for herbalists to present cautions about herb use. Some cautions are based on known effects, something that may have been observed in people using the herb or something that was revealed in laboratory experiments. Others are based on lack of knowledge and a desire to avoid problems that could theoretically arise. For example, pregnant women are advised to either avoid use of herbs, use a lower dose of herbs, or use herbs only for a short time, because the potential impact of large amounts, especially if consumed regularly, is either unknown or theoretically problematic.

Many people feel that herbal medicine was suppressed by those who promoted the use of drugs. This is not a true depiction of the situation. Drug therapies, when they first became widely available, were embraced enthusiastically and almost universally by both doctors and patients. The potency, reliability, and ease of use apparent in the drug therapies available during the first half of the 20th century was sufficient to convince most people that this was certainly the direction that medicine ought to follow. The remarkable difference between the high rate of death by infection before penicillin and after its introduction could leave little doubt about its efficacy and appropriateness. Similarly, the acceptance was great for opium-derived pain relievers (morphine and its analogues), powerful anti-inflammatories (corticosteroids and non-steroidal anti-inflammatories), birth control pills, and numerous other medical achievements. It was only after almost the entire population had come to rely heavily and regularly on these drugs that the concept that this might not be the way to go became a significant concern. For those who then turned to herbs and other natural remedies, it was often an unrecognized luxury to be able to do so: these same individuals may have been saved from death, deformity, or debility by previous use of antibiotics, vaccines, and other modern medical interventions.

What had happened was not a conspiracy by doctors, pharmaceutical firms, and regulatory agencies (e.g., FDA) to displace herbs and make people dependent on drugs; rather, it was an across the board acquiescence to the process of discarding several valuable aspects of traditional life style, thus making herbs less attractive and drugs more attractive.

Herbs were set aside because they were perceived as having a low efficacy, slow action, inconvenient administration, and unreliable composition. Consider Künzle's spring cure. One first has to find a "Tony and Jack" willing to go out in the frosty early spring air and collect thorny sprigs (which are increasingly hard to find within the city). Then, one has to take the time to boil it up, and drink the bitter decoction (flavored with sugar, but, not what modern people have come to like in a medicine). This has to be continued for a week or more. Consider how much more convenient it is to take a single analgesic drug tablet for a headache, and a couple of capsules of fiber for the constipation. Further, one expects from these pills to get results right away, not after a week or two.

What people are slowly coming to realize is that a gentle action is not the same as low efficacy; that a slow action does not imply an undesirable outcome; and that inconvenient administration can be largely resolved, as long as one is able to tolerate things in a more natural form. Increasingly, drugs are being viewed not just as powerful remedies but as harsh remedies. The gentle action of herbs, therefore, has attained a certain degree of attractiveness. Why stop the body from producing stomach acid that is otherwise needed for good digestion, when one can eat right and take an herb that will improve the digestive function?

Few can argue with the desirability of fast action, but many more are awakening to the fact that something that works quickly often leaves the disease intact, there to be treated again and again and again, each time with increasing threat of drug side effects. The slow action of herbs is just right for an accompaniment to a gradual change in life style (even a temporary change) until more solid health is attained. While it may be increasingly inconvenient to go out and collect herbs and cook them up, large herbal companies have arisen to address the demands of a huge global market. They have hired people to raise, harvest, and process the herbs into a form that is ready to use. By carefully selecting from the full range of available herbs, the manufacturer can often produce remedies that have a tolerable taste (if not actually pleasant) or can prepare ready to ingest forms, such as teabags for brewing a tea, or powders and extracts made into convenient pills.

Consider the use of orange blossom, an ingredient of some of Kunzle's herbal teas. In the addendum to Herbs and Weeds that was added in 1975, it is mentioned that:

Orange blossoms are considered to be a pleasant and absolutely harmless sedative for the nerves which explains why they are mainly used as an ingredient in teas to calm the nerves and to encourage sleep. They are also suitable for correcting the scent and taste in remedies.

These blossoms would be difficult to come by in many locations, so the modern efforts to gather herbs from around the globe resolves that problem. The safety and mild action are desired by those who worry about the potency of drug sedatives or potential adverse effects of strong-acting herbs, and the blossoms make the herb tea more pleasant to drink.

The problem of unreliability of herb resources-variability in the origin and quality of the herb materials-has been addressed by applying advanced quality control measures in making herbal products. Manufacturers are able to employ botanist consultants to confirm the identity of materials and chemical analysts to assure that key active ingredients are present (and in adequate quantity). Food safety laboratories or in-house scientists are able to check for bacteria, yeasts, heavy metals, and pesticides. Pharmacy authorities have surveyed the known literature to determine which herbs are generally recognized as safe and what cautions should be pursued (as was done for the German Commission E). Nowhere are these quality control efforts more intensively pursued than in Europe, where herbs have remained a part of the health care system throughout the 20th century, when the stringent drug standards were developed.