The willow is a symbol of the changeable human spirit and of immortality. In the Shaker tradition, numerous song references are made to the willow. “I will not be like a stubborn oak, but I will be like the willow tree. . .,” one song begins. Another song starts, “Yielding and simple may I be like a pliant willow tree.” These and many other references to the willow remind us of a capacity for change.
So many willows
Botanically, the genus Salix, to which the willows belong, is itself a symbol of change. The genus contains more than 400 species, primarily native to the Northern Hemisphere, with some species growing south to the equator as well. In China alone, there are more than 250 willow species. They hybridize readily, and for the botanist, the genus represents a taxonomic nightmare. There are more than fifty species of willows in the eastern United States, and California has more than thirty species. The willow family (Salicaceae) is represented by two genera, Salix and the poplars (Populus). Salix is the classical name for the willow tree.
Of the eighty or more species of willows occurring in North America, most are low-growing shrubs. About a third of the species are trees. In addition to the native species, several European and Asian species are cultivated in American horticulture. A number of these, including European white willow (Salix alba), have been naturalized in this country. The European white willow and the American black willow (S. nigra) are both more or less typical of the genus, in terms of botanical characteristics and medicinal use. Most herb books mention the main source of willow bark as S. alba. Black willow is one of the most common willow species in North America, and was probably the most widely used species among Native American groups.
The black willow is one of the loftiest representatives of the genus in North America, growing to a height of thirty to forty feet. Sometimes it may become a massive tree more than 100 feet tall. It was commonly used as a material as well as a medicine. Willow switches were often used as horse whips, and were used when a combination of toughness and elasticity were required, such as in the manufacture of rustic chairs and baskets. The tough, stringy bark was used for making cords and mats, fishing nets, harnesses, and more. Its high tannin content made it suitable for tanning and dyeing. Willow switches were commonly used by Native Americans as a building material for the frames of temporary shelters, sweat lodges, and furniture. Women and children wove sunshades from the leafy stems for long journeys.
Native Americans used numerous willow species. S. nigra root bark was used by the Houma as a blood thinner. The Chippewa used the root for diarrhea, and in combination with other herbs to treat indigestion. The Creek used the root tea as an anti-inflammatory for rheumatism and to reduce fevers. The Penobscot used willow bark as a cold remedy, and smoked the leaves to relieve asthma. The Ojibwa used one willow species to treat colds. Many tribes used the leaves as a poultice for wounds and sores. The Kiowa rubbed the leaves on their bodies to treat rheumatic pains, and chewed the leaves to relieve toothaches. The Chickasaw used the roots of one willow species to treat headaches. The Montagnais made a poultice of the leaves that was applied to the forehead to relieve headaches. In short, Native Americans from Florida to California to Alaska used willow bark as modern Americans use aspirin. In American folk traditions, the bark was used as a blood thinner (like aspirin), and to treat fevers.
Toward modern medicine
Willow bark’s modern history began in the mid-eighteenth century. Reverend Edward Stone wrote a short note published in the Philosophical Transactions of the Royal Society in London, in which he reported on the successful use of white willow bark to treat intermittent fevers (malaria). From this one report, willow bark became a popular substitute for Peruvian bark or cinchona (source of quinine) among European and American physicians of the late-eighteenth and early-nineteenth centuries. In his American Dispensatory (1813), James Thatcher tells the story. “In 1763, Mr. Stone, an English clergyman, presented a paper to the Royal Society, on the beneficial effects of the Salix alba, or white willow, in intermittent fevers; and Dr. Cullen, on this authority, and from the sensible qualities it possesses, recommends it, in his Materia medica, as a substitute for the cinchona. Mr. Stone gathered the bark in the summer, when it was full of sap; dried it by gentle heat, and gave a drachm of it powdered every four hours, betwixt the fits. In a few obstinate cases he mixed it with one-fifth part of the cinchona. Some judicious physicians here, says Dr. Cutler, made trial of the bark of white willow, and recommend it as a valuable substitute for the Peruvian bark. They have used principally the bark of the root.”
White willow is the “classic” willow, used medicinally since the time of the ancient Greeks. Many willow species are used interchangeably. Writing in King’s American Dispensatory in the early 1900s, H. W. Felter and J. U. Lloyd state: “There are numerous species of Salix, many of which, undoubtedly, possess analogous medicinal virtues. The best rule to follow is to select those whose barks possess great bitterness, combined with astringency.”
While white willow is listed in most of the herbal literature as a primary source for willow bark, four other European species are recognized as sources of medicinal willow. These include S. fragilis, S. purpurea, S. daphnoides, and S. pentandra. All except S. daphnoides are naturalized in North America. White willow contains only small amounts of the active constituent salicin (0.5 to 1.0 percent), whereas the other recognized species contain much higher amounts. S. purpurea contains 6.1 to 8.5 percent salicins; S. daphnoides contains 4.9 to 6.4 percent; and S. fragilis contains 3.9 to 10.2 percent. The total content of salicin is highest in spring or summer and lowest in winter.
Comparisons to aspirin
Salicin is a white or colorless, silky, shining crystalline substance, found in most species of willows and in poplars. It is the primary chemical component responsible for the therapeutic qualities of willows, including fever-reducing, mild anti-inflammatory, and mild pain-relieving and blood-thinning effects.
Willow has emerged as the best-known herbal alternative to nonsteroidal anti-inflammatory synthetic drugs. While aspirin is chemically related to analgesic compounds in willow bark, aspirin, contrary to popular belief, was never derived from willow. Aspirin was discovered as a result of research on compounds found in willow (as well as a number of other plant species).
In ancient times, willow was used for the treatment of the pain of arthritis and rheumatism. People made special clay pots in which willow was soaked in olive oil, then submerged their ailing joints in the pots to help relieve pain. Seldom used in the ensuing centuries, modern interest in willow was sparked in 1763 by a French scientist, Leroux. He first isolated salicin from willow bark and published his findings in 1830. In 1838, salicylic acid was prepared from salicin. In 1839, salicylic acid (also called spiric acid) was also obtained from the flowerbuds of Filipendula ulmaria (also known as Spirea ulmaria). Salicylic acid was used to reduce the discomfort of rheumatic fever, as well as for rheumatic pains, lumbago, sciatica, and for its diuretic activity. However, it caused numerous side effects such as roaring in the ears, vertigo, and profuse sweating, and it was extremely irritating to the stomach.
In the 1890s, a chemist under the employ of Heinrich Dreser, director of a research group at Bayer in Germany, brought a sample of acetyl salicylic acid to Dreser. The researchers were interested in developing a safer, non-irritating derivative of salicylic acid. To see if it produced local irritation like salicylic acid did, Dreser tested acetyl salicylic acid on the gills of live goldfish. It proved to be far less irritating. Clinical trials were initiated, and in 1899 Bayer launched this new form of salicylic acid. At first it was called acteyl-spiric-acid (from the form of salicylic acid isolated from Spirea), then asperic acid, and finally it came to be known as aspirin. Before long, it became the most widely used drug in the world, second only to alcohol.
In modern herbal practice, willow bark teas and extracts are still used. Willow bark contains compounds called phenolic glycosides esters, including salicin and related compounds, such as fragilin, temulacin, and others, collectively known as salicortin. When the bark is exposed to high temperatures, these compounds are transformed into salicin. Intestinal microorganisms transform these compounds into saligenin, which becomes oxidized in the liver and blood, to produce salicylic acid, which has pain-relieving effects.
How much is enough?
The question then becomes whether you can take enough willow bark to achieve pain-relieving effects. According to the late Varro Tyler, Ph.D., the answer is probably not, at least not in doses large enough to treat arthritis. A standard dose of willow is 1 to 2 g of the powdered bark (about 1/4 to 1/2 teaspoon), corresponding to 20 to 40 mg of salicin. Taken three times a day, it could deliver as much as 120 mg of salicin. Tyler calculated that, based on the low salicin levels in most commercial willow bark samples, it would take between 6 cups and 1.25 gallons of willow bark tea to achieve a single dose of salicin equivalent to an average daily dose of aspirin high enough to treat arthritic pain. Another problem with drinking willow bark tea is its astringent taste. The first time I tried to drink a strong tea of willow bark to treat a fever was, in fact, the last time I tried it.
The solution comes in producing a willow bark product that contains enough salicin to deliver an effective dose. Standardized willow bark products that contain 41 mg of salicin per 270-mg capsule of willow bark extract are available at health-food stores. According to the German Commission E monograph on willow bark, the bark should contain at least 1 percent salicin, with a daily dose of 60 to 120 mg of total salicin.
Despite its long-term use for purposes similar to aspirin, there have been few clinical studies on the effectiveness of willow bark preparations. The most recent study was published in the American Journal of Medicine in 2000. The study looked at the “treatment of low back pain exacerbations with willow bark extract.” Two hundred and ten patients with chronic low-back pain were recruited for the study. The patients received willow bark extract with either 120 mg of salicin (low dose), a higher dose with 240 mg of salicin, or a placebo. The study lasted for four weeks. Data was available on 191 patients at the end of the study. Those receiving a high dose showed response after only one week of treatment. Thirty-nine percent of patients in the high-dose group and 21 percent in the low-dose group (only 6 percent in the placebo group) were pain-free in the last week of treatment. The authors concluded that willow bark extract may be safe and useful for the treatment of low-back pain. The positive outcome of this trial may help pave the way for further studies.
For more than 2,000 years, people of the Northern Hemisphere have utilized the bark of willow species. Today, aspirin, perhaps the most popular twentieth-century drug, serves the same purpose. Properly formulated willow bark products that deliver a predictable level of active constituents can have similar effects. Hidden in the history of the willow is the knowledge that plants hold many unrevealed secrets for the future benefit of the human race.
Chrubasik, S., et al. “Treatment of low back pain exacerbations
with willow bark extract: a randomized double-blind study.”
American Journal of Medicine 2000, 109: 9–14.
Foster, S. Herbs for Your Health. Loveland, Colorado: Interweave Press, 1996.
Foster S., and Tyler, V. E. Tyler’s Honest Herbal (4th ed.). Binghamton, New York: Haworth Herbal Press, 1999.
Tyler, V. E. Herbs of Choice: The Therapeutic Use of Phytomedicinals. Binghamton, New York: Pharmaceutical Products Press, 1994.
C a p s u l e s
Valerian-hops combination improves sleep
If two herbs can be commonly associated with sleep, they are valerian (Valeriana officinalis) and hops (Humulus lupulus). Valerian’s reputation as an herbal antispasmodic and sleep aid did not emerge until about 500 years ago. Hops has been recognized for its sleep-inducing qualities since ancient times. Because of its bitter flavor and ability to produce relaxation, hops emerged as the perfect flavoring ingredient for beer many centuries ago.
At least eleven clinical studies have assessed the benefits of valerian preparations on reducing the time it takes to fall asleep and improving sleep quality and the length of a full night’s rest. The results have been generally positive. Most of the studies from the 1980s looked at the effect of valerian on sleep when given just before bedtime, on an acute basis. A recent clinical study suggested that it might require taking a valerian preparation for a month or more before experiencing significant benefits in improving sleep quality.
Far fewer studies have been conducted on hops. Traditionally, hops was used as a sleep aid, and the two herbs have long been used in combination. At least two studies have shown that a combination of hops and valerian may interact with GABA-ergic receptor systems, thus inducing brain hormones to heighten a good night’s sleep. Both contain amino acids that may chemically activate this hormone system, but a single active constituent from either plant that improves chemical mechanisms related to sleep has yet to be identified. Therefore, researchers suggest the “full extract” must be regarded as the active substance.
Sleep disorders are one of the most common health complaints in industrialized societies, experienced by between 20 and 30 percent of the population. Therefore, finding a safe and effective herbal sleep aid with few or no side effects is appealing. Recently, researchers at German and Swiss institutions conducted a pilot study on the effects of a fixed-extract valerian-hops combination called Ze 91019 in thirty patients with mild to moderate non-organic insomnia. The product, manufactured by Zeller AG in Switzerland, is sold in several European countries under various trade names. In the United States, the product is marketed under the name Alluna® and advertised on national television as a “natural sleep aid.”
In the open, uncontrolled pilot study, patients selected had been sent to a sleep laboratory for diagnosis. Once they agreed to participate, they received two tablets each evening for two weeks. Each tablet contained 250 mg of a valerian extract and 60 mg of a hops extract. After two weeks, the patients were reassessed by the sleep laboratory using a battery of tests, measuring the amount of time it took to go to sleep, length of sleep, and how refreshed the patients felt upon awakening. Overall sleep efficiency increased, and numbers on several parameters, including sleep latency (the time between turning off the light and falling asleep) and total waking time (while lying in bed), decreased significantly. The ratio of true sleep time compared to time spent in bed also improved. No adverse effects were recorded. The researchers stated that the successful results of the pilot study set the stage for a larger controlled clinical study. (1)
Garlic and cancer
Garlic is a food, medicine, and flavoring. Its complex chemistry has lent itself to hundreds of documented uses, ranging from Hippocrates prescribing it for lung ailments to the ancient Chinese using it for sadness and depression. In recent years, many epidemiological and pharmacological studies have shown that various foods such as soybeans, broccoli, and Alliums (such as garlic and onions) may affect the incidence of cancer rates among various populations. Animal and laboratory studies have provided evidence that garlic may produce cancer-protective or anticancer effects for cancers of the stomach, head and neck, colon, lung, breast, and prostate.
Researchers at the Department of Epidemiology at the University of North Carolina at Chapel Hill recently published an assessment of nineteen studies that reported relative estimates of how garlic consumption may affect cancer incidence. Using a complex statistical analysis of the studies and their quality, the assessment revealed that a high intake of fresh or cooked garlic may have a protective effect in stomach and colorectal cancers. Four studies and one case-control report on garlic supplements showed that the supplements did not appear to reduce the risk of cancer in specific populations. The researchers found that some of the studies were conducted on too few participants, some were poorly designed, and some may have had biased results.
The authors concluded that the available studies suggest a
preventive effect of garlic consumption in stomach and colorectal
However, they caution that limitations of existing studies point to the need for more definitive research and improvement of nutritional epidemiological data. Most readers of The Herb Companion probably prefer their garlic in haute cuisine rather than capsules, anyway.
(1) Fussel, A., et al. “Effect of a fixed valerian-hop extract combination (Ze 91019) on sleep polygraphy in patients with non-organic insomnia: a pilot study.” European Journal of Medical Research 2000, 5:385–390.
(2) Fleischauer, A. T., and L. Arab. “Garlic and cancer: a critical review of the epidemiologic literature.” Journal of Nutrition (Supplement) 2001, 1032S–1040S.