Herbal Drugs - Effects on the Body
Effects on the Body
Some widely used herbal remedies include chamomile, echinacea, garlic, ginkgo, ginseng, green tea, saw palmetto, St. John's wort, and valerian.
Chamomile
Chamomile is a popular herbal remedy. The plant's daisy-like flowers smell like apples. Chamomile tea, made from dried flowers, is said to produce a calming effect and to ease an upset stomach. According to Penelope Ody in The Complete Medicinal Herbal, "One home-dried flower can give more flavor than a tea bag of commercial offerings." Despite its widespread use, chamomile tea may bring on severe respiratory reactions if consumed by people with allergies to ragweed and certain flowers.
Echinacea
Several varieties of echinacea, also called the purple coneflower, are said to strengthen the body's immune system and fight colds and flu. Before Europeans arrived in the New World, echinacea was used by Native Americans to treat respiratory infections, inflammation of the eyes, toothaches, and snakebites. Colonists quickly adopted the use of the herb. In the nineteenth century, European Americans used echinacea as a "blood purifier," believing that it cleared the blood of disease-causing toxinsHarmful, poisonous, or capable of causing death..
Whether echinacea is really an effective substance in treating or preventing colds is debatable. Sixteen clinical trialsScientific experiments that test the effect of a drug in humans., or scientific tests, involving more than 3,000 patients have produced mixed results. A 2003 study funded by NCCAM looked at the use of the herb as a cold treatment in children age two through eleven. Researchers found that the "use of echinacea from the onset of symptoms did not lessen the number of days the cold lasted or the severity of the symptoms." Furthermore, researchers suggested that additional studies be conducted "to determine whether echinacea has any role in preventing colds."
Echinacea is not known to interact negatively with any other drugs. However, it can cause serious reactions in people with allergies to certain plants and flowers. Additionally, it is not recommended for use by people suffering from diseases of the immune system. In Germany, echinacea is valued as an immune-boosting herb and is often combined with antibiotics to treat bacterial infections. No studies have evaluated the safety or effectiveness of this combination.
Garlic
According to Mark Blumenthal, founder and executive director of the American Botanical Council, garlic dietary supplements were the top-selling herbal supplement in the United States in 2004. Fresh and dried garlic is used to treat the common cold, coughs, bronchitis, fever, and inflammation of the mouth. More than two dozen clinical trials have tested garlic's cholesterolPronounced kuh-LESS-tuhr-ol; an essential substance made of carbon, hydrogen, and oxygen that is found in animal cells and body fluids; in high amounts, it may be deposited in blood vessels, resulting in dangerous blockages of blood flow.-lowering properties. Preliminary results indicate that garlic can actually reduce cholesterol levels, but the degree of reduction was rather low, at about 10 percent overall.
In April of 2005, results of a German study on Kwai garlic were detailed in a press release posted on the American Botanical Council Web site. The study showed "that garlic can play a role in preventing and potentially reversing or dispersing arteriosclerotic plaque formation." This means that the active ingredients in garlic help to flush away the clogging deposits that can build up inside blood vessels. In addition, garlic may actually stop plaque from developing in the first place. The presence of plaque in the blood vessels "can lead to a number of cardiovascular illnessesIllnesses involving the heart and blood vessels., including high blood pressure and strokeA loss of feeling, consciousness, or movement caused by the breaking or blocking of a blood vessel in the brain.," noted the press release.
On the downside, the use of garlic supplements can cause bad breath, body odor, and intestinal gas. Depending on the brand and dosage taken, a garlicky smell may be excreted through the skin and mouth of garlic supplement users. Although odor-free garlic pills are available, herbalists generally agree that some of the herb's medicinal value is lost during processing.
Garlic is also used in the treatment of menstrual pain and diabetes, although its effectiveness for these conditions has not been determined.
Ginkgo
The wild maidenhair tree, or ginkgo tree, dates back "at least 200 million years," noted Ody, "but cultivated trees survived in Far Eastern Temple gardens." The tree grows in eastern China and is known for its shade-producing fan-shaped leaves. In 1730, the tree was brought to Europe from China. It was not until the 1950s that a German researcher investigated the properties of the ginkgo leaf for possible medical use. Asian herbalists brew teas from ginkgo to treat memory loss and asthma. Ginkgo supplements began catching on in the United States in the 1980s.
Ginkgo contains a substance that helps dilate, or open up, blood vessels, thus improving blood circulation throughout the body. It is often used to relieve the pain associated with poor circulation in the legs. The herb is also said to improve, or at least stabilize, age-related memory loss and the mental confusion that accompanies Alzheimer's diseaseA brain disease that usually strikes older individuals and results in memory loss, impaired thinking, and personality changes; symptoms worsen over time.. These actions are credited to gingko's ability to increase blood flow to the brain.
Ginseng
Ginseng is a Chinese herb, but a ginseng-like herb grows in North America. The ginseng plant has five leaflets per leaf, bright red berries, and roots that are believed to have a variety of medicinal uses. When dried, the roots are considered a type of "general tonic" that protects users from disease, increases stamina and sexual power, and aids in concentration. It reportedly takes several weeks of regular use for the effects of ginseng to kick in. As of 2004, few studies of ginseng had been conducted in the United States. Although used in China for more than five centuries, the herb has "only recently become popular in the West," explained Andrew Weil and Winifred Rosen in From Chocolate to Morphine, "and Western scientists still do not understand it very well."
Green Tea
Green tea is widely regarded as an immune-system booster. Herbalists from the Far East claim it helps prevent stomach cancer. It also has a rather unusual effect. Because of its high fluoride content, green tea may reduce the risk of tooth decay. Its caffeine content can cause nervousness and insomnia in some individuals.
Saw Palmetto
Saw palmetto grows along the southern coastal regions of the United States. Tea made from the plant's berries is used to relieve urination problems caused by an enlarged prostateA male reproductive gland. gland. Sixteen short-term clinical trials involving approximately 3,000 men indicate that saw palmetto is effective for this use, although long-term trials need to be done to confirm the herb's effectiveness. The herb improves urine flow and is commonly prescribed in Europe for men with an enlarged prostate. Saw palmetto is also available in tablet and capsule form.
St. John's Wort
St. John's wort, a low-growing bush with yellow flowers, contains about ten different compounds that can exert effects on the human body. The dried buds and flowers of this plant are used to treat depression and anxiety. Studies on the herb involving thousands of patients were conducted throughout the 1990s. The results showed that St. John's wort seemed to work about as well as prescription antidepressants on mildly to moderately depressed patients—with fewer side effects. (A separate entry on antidepressants is available in this encyclopedia.)
In early 2005, a European study confirmed these results but went one step further. The British Medical Journal reported on the study in its February 11, 2005 issue, noting that German researchers found St. John's wort equally effective in patients who had been diagnosed with moderate to severe levels of major depression. The National Institutes of Health (NIH), however, maintains that St. John's wort has not been proven effective in treating severe depression.
Valerian
Valerian grows naturally in Europe and Asia and was brought to North America. Its rhizomes, or underground stems, are used to make teas and other herbal remedies for nervous tension and insomnia. Weil and Rosen described valerian as "a strong natural sedativeA drug used to treat anxiety and calm people down. that does not depress vital functions or cause the kind of dependence that sleeping pills do." Experts claim that fresh valerian is far superior to pills and capsules because the manufacturing process makes the rhizomes lose their strength. Some users swear by its calming effects, even if it does smell like stinky gym shoes.
Lesser-Known Herbs
In late 2004 and early 2005, the American Botanical Council published new research results on butterbur and elderberry. An extract of the European butterbur root significantly reduced the number of migraine headache attacks in children and adolescents, according to a four-month study documented in Headache. Migraines are especially difficult to treat in children, and conventional drugs often fail to relieve young patients' pain. The butterbur remedy, though, cut the number of migraine episodes in half for more than three out of four children in the study.
Results of trials using elderberry for flu symptoms were promising as well. The European elder tree has creamy white flowers and bluish-black berries. The flowers and berries of the plant have gained popularity in the United States in the treatment of coughs, colds, fever, and flu. In clinical trials cited in "The ABC Clinical Guide to Elder Berry," elderberry syrup was shown to be effective in reducing flu symptoms. "The treatment group recovered significantly faster (by days two or three) than the control groupIn a drug test, the group that does not receive the drug being tested. (by day six)," according to the guide.
Ephedra and Other Potentially Dangerous Herbs
The long-term health effects of herbals have not yet been determined. Some herbals, however, are known to cause serious side effects. Among them are ephedra, comfrey, kava, and pennyroyal. (A separate entry on ephedra is available in this encyclopedia.)
The Chinese herbal remedy ephedra, also called ma huang (ma-HWANG), received more press coverage in the early 2000s than any other herb. The twigs of this desert plant have been used as a treatment for asthma for thousands of years. Ephedra contains amphetaminesPronounced am-FETT-uh-meens; stimulant drugs that increase mental alertness, reduce appetite, and help keep users awake.-like substances that can have a powerful stimulating effect on the heart. (A separate entry on amphetamines is available in this encyclopedia.) Until it was banned by the FDA in 2004, ephedra was most often taken by young and middle-aged adults for weight loss, increased energy, and bodybuilding. Serious side effects associated with ephedra include high blood pressure, irregular heart rate, seizures, heart attacks, and strokes. According to FDA figures, the use of this herbal stimulant has been linked to 155 deaths. As of early 2005, the controversy surrounding ephedra—and its ban—had not been settled.
Herbalists have prescribed comfrey tea and pills to treat back pain, ulcers, and diarrhea. Ointments were used traditionally to heal bone fractures. However, the FDA advised dietary supplement manufacturers to take comfrey off the market in 2001 because of mounting evidence that comfrey tea and pills can cause severe damage to the liver. The FDA also noted a lack of evidence for comfrey's effectiveness.
Kava is taken from the roots of a plant found on the South Pacific islands. The root can be chewed or brewed into a tea, but capsule and tablet forms are also available. This spicy herb is related to black pepper. Kava acts as an herbal depressantsSubstances that slow down the activity of an organism or one of its parts., reportedly bringing on feelings of relaxation and numbness in the user. In the 1990s, it was a popular remedy for stress and anxiety. It has also been used for its anestheticA substance used to deaden pain. properties. Preliminary research shows that regular use of kava reduces anxiety, tension, and agitation without the side effects of prescription anti-anxiety drugs such as benzodiazepinesA type of drug used to treat anxiety.. (A separate entry on benzodiazepines is available in this encyclopedia.) Weil and Rosen noted, however, that "cases of severe liver disease" have been reported "in people using kava; as a result, its popularity has dropped off sharply" in both the United States and Europe since the early 2000s.
Pennyroyal is a widely available herb of the mint family. It is usually consumed as a tea and used for digestive disorders, colds, and skin diseases. At high doses, it can cause pregnant women to abort their babies. Also, it is known to be toxic to the liver.
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