By Jack Challem
Copyright 2000 by Jack Challem, The Nutrition Reporter™
All rights reserved. This article originally appeared in Let's Live magazine.
Thousands of years ago, the Chinese were taking ginkgo to keep aging minds sharp. In ancient Greece, women used the herb Queen Anne's lace as a contraceptive. And for centuries, Native Americans used echinacea to fight infections.
Herbal medicines have been used by every human society to treat one ailment or another, and archeologists have even discovered remnants of herbal remedies in 60,000-year-old Neanderthal burial sites. But for most of the 20th century, American physicians-enamored by synthetic drugs and influenced by pharmaceutical advertising-have been quick to dismiss herbs as crude and unproven folk remedies.
That's now starting to change. New scientific evidence supports the benefits of herbal medicines, and more consumers are opting for natural and nontoxic treatments.
"Keep in mind that 25 percent of our conventional prescription drugs are derived directly or indirectly from plants," explains Varro Tyler, Ph.D., professor emeritus at Purdue University, West Lafayette, Ind. "And these 25 percent of drugs furnish the template for 90 percent of modern synthetic drugs."
Aspirin, perhaps the most common drug for treating headaches, originally came from willow bark. Quinine, used to prevent malaria infections, was once obtained from the bark of a Peruvian tree. Vinblastine, a drug used to treat leukemia, comes from periwinkle plants. And digitalis, a heart stimulant, is still made from pressed foxglove leaves.
"So there's ample precedent for natural products having health benefits," adds Tyler.
Why Are Herbs Antioxidants?
Herbal medicines may be steeped in folklore, but in recent years, methodical research has borne out many of their traditional health benefits. Contributing to the growing acceptance of herbal medicines is the "free radical" theory of aging.
Free radicals are hazardous molecules found in pollutants and also produced when the body converts food to energy. These molecules oxidize, or damage, normal cells. In doing so, they accelerate the aging process and set the stage for most degenerative diseases, including heart disease and cancer. Free radicals, however, can be quenched by antioxidants, of which the best known ones are probably vitamins C and E.
As the free radical theory of aging gained momentum in the scientific community, researchers began investigating the antioxidant properties of plants. It turned out that the lion's share of antioxidants in fruits, vegetables, herbs, and other plant foods aren't in the form of vitamins. Most of the antioxidants occur as phenols, polyphenols and flavonoids, three large and related families of antioxidant compounds, according to Ronald L. Prior, Ph.D., a researcher at Tufts University, Medford, Mass.
All of these compounds protect plants from free radicals, which are generated by sunlight, pollutants, and weather-related stresses. When people eat plant foods, they acquire the protective benefits of these antioxidants. Some polyphenols and flavonoids also influence the function of genes and have hormone-like properties, much the way some vitamins do.
James A. Duke, Ph.D., a respected medical botanist and author of The Green Pharmacy (Rodale, 1997) believes that many phenols, polyphenols, and flavonoids are practically essential nutrients, based on the fact that people and other animals regularly consumed these compounds over millions of years of evolution.
While all plants contain polyphenols and flavonoids, genetic differences between plants lead to distinctly different chemical "fingerprints" of these compounds. That's why one herb may have certain health benefits, while another has very different effects. For example, the distinctive chemical structure of ginkgolides, found in ginkgo, exert their effect primarily on blood vessels in the brain. In contrast, the echinosides and other compounds in echinacea have different chemical structures, which turn on disease-fighting immune cells.
Do Herbs Help Regulate Metabolism?
In addition to being antioxidants, herbs also work in other important ways-providing near-essential compounds that normalize the body's activities. For example, the berries of saw palmetto, a small palm tree that grows in the southeastern United States, inhibit the activity of an enzyme involved in causing benign prostate enlargement. St. John's wort lifts mood partly by blocking the activity of monoamine oxidase, an enzyme that promotes feelings of depression.
Recently, molecular biologists have begun unraveling the most basic details of how some herbs work. Rajesh Agarwal, Ph.D., and his colleagues at the AMC Cancer Research Center, Denver, have investigated how silymarin, an antioxidant extract from milk thistle seeds, inhibits the growth of breast, prostate, and skin cancer cells.
In one experiment, Agarwal looked studies defects in the cell cycle of breast cancer cells. Cell growth and replication are controlled by what is, in effect, a biological clock, and growth takes place in well defined steps in the cell cycle. However, cancer cells often have defects in this cell cycle.
Agarwal found that silymarin inhibited the growth of breast cancer cells by stopping the cell cycle-essentially by stopping the clock-when cancer-causing DNA was about to be replicated for news cells. The cancer-halting effect of silymarin was related to the dose of the herb, and larger amounts were more effective than smaller amounts in stopping the growth of breast cancer cells.
Are Herbs Drugs or Foods?
So, are herbal medicines drugs or foods?
Many of the phenols, polyphenols, and flavonoids found in herbal medicines are also found in fruits and vegetables, and they are a big part of the reason why such foods reduce the risk of cancer and other diseases. These compounds have been part of the diets of humans and primates for millions of years.
Pharmaceutical drugs and herbal medicines work in very different ways, says Tyler. Most drugs are based on single, or "mono," compounds. Even when these compounds are derived from herbs, they have a singular action in the body. In contrast, "herbs seem to work in many different ways," and generally have a low risk of side effects, according to Tyler.
The other advantage to herbs, points out Duke, is that their multiple compounds tend to act in a synergistic fashion; the sum benefits are greater than those of any single part.
Herbs, then, are more similar to a dinner salad in chemical composition than to a modern pharmaceutical drug. In a sense, herbal medicines provide a concentrated dose of natural antioxidants and other important health-promoting compounds. While herbal medicines should never substitute for a wholesome diet, they can provide and replenish many biologically active compounds that contribute to health.
A Potpourri of Herbs
These are some of the most popular herbal supplements sold. The dosage recommendations are general, because potencies vary among the many different preparation methods and brands. In general, follow label directions, the guidance of a knowledgeable physician, or the instructions in books written by herbal experts.
Immune Booster: Echinacea
Research: Echinacea turns on some of the body's immune cells. Recent studies have confirmed that echinacea can bolster resistance to colds and flus.
Cautions: People with autoimmune disorders, such as lupus and AIDS, should take echinacea under a physician's supervision.
Dosage: 300-800 mg daily.
Hot Tips: The immune-enhancing effect takes several weeks to build up.
Blood Thinner: Garlic
Research: Many people think of garlic as a food or condiment rather than as an herb. There's probably more science to back it up than on any other herb. It's a natural blood thinner and cholesterol-lowering herb. Garlic is also a powerful immune stimulant that can help you resist disease.
Cautions: Exercise caution when combining large doses of garlic with other blood thinners, such as ginkgo, aspirin, and the drug Coumadin.
Dosage: 400-7,000 mg daily.
Hot Tips: Every form of garlic has health benefits. Cook with garlic for taste, or take capsules for convenience.
Brain Preserver: Ginkgo
Research: A study in the Journal of the American Medical Association recently reported that ginkgo supplements can slow the progression of Alzheimer's disease. The obvious question: why wait that long to take it?
Cautions: Ginkgo is a blood thinner, so exercise caution if you regularly take other blood thinners, such as aspirin.
Dosage: 40 mg three times daily.
Hot Tips: A ginkgo extract known as EGb 761 has been extensively tested and shown to enhance mental function.
Antiinflammatory: Cat's Claw
Research: Cat's claw is a traditional Peruvian folk remedy for inflammation and arthritis. Recent studies have found that it is a powerful antioxidant and antiinflammatory, giving credence to its historical use. Cat's claw also inhibits the body's production of "nuclear factor kappa-B," which promotes inflammatory reactions.
Cautions: People receiving a skin graft or organ transplant should not take cat's claw. Excessive intake may result in diarrhea.
Dosage: 150-250 mg daily.
Hot Tips: Cat's claw may also reduce the long term risk of cancer.
Stress Fighter: Ginseng
Research: Considered an "adaptogen" because it helps people adapt to stress, ginseng functions as a general tonic that increases well being. The antioxidants it contains may protect the brain from damage.
Cautions: Ginseng may make some people may feel anxious or overstimulated.
Dosage: 400-500 mg daily.
Hot Tips: Siberian ginseng enhances resistance to stress, whereas Panax ginseng increases physican and mental stamina.
Heart Strengthener: Hawthorn
Research: The berries of this tree can strengthen a weak heart. It does so gently and apparently without the side effects of other types of heart stimulants.
Cautions: If you are currently taking medication for heart failure, consult with your physician before taking hawthorn. so you don't overmedicate yourself.
Dosage: 240-480 mg daily
Hot Tips: Hawthorn is a powerful antioxidant, and it may also ease inflammation.
Circulation Enhancer: Horse Chestnut
Research: This herb, made from the seed pod of the horse chestnut tree, can benefit many circulatory disorders, including intermittent claudication (also known as "restless legs").
Cautions: Horse chestnut appears safe.
Dosage: 200-400 mg daily.
Hot Tips: Although scientific evidence is lacking, horse chestnut may be beneficial for varicose veins and hemmorhoids.
Antioxidant: Pycnogenol®
Research: Various tree barks have long been used medicinally. Pycnogenol® might be best considered an herbal antioxidant. Derived from the bark of French maritime pine trees, it has potent antiinflammatory properties.
Cautions: No documented side effects, even at high dosages.
Dosage: 25-100 mg daily.
Hot Tips: There is some preliminary evidence that Pycnogenol® may reduce symptoms of attention deficit disorder.
Anti-Depressant: St. John's wort
Research: St. John's wort is the premier natural antidepressant. In a review of the research on this herb, the British Medical Journal found that it worked better than prescription antidepressant drugs and had fewer side effects.
Cautions: It sometimes increases skin and eye sensitivity to sunlight.
Dosage: 300 mg daily.
Hot Tips: St. John's wort usually takes about one month to have a noticeable effect.
Prostate Healer: Saw palmetto
Research: The berries of this small palm tree ease urinary problems associated with benign prostatic hyperplasia, more commonly known as enlarged prostate. The condition is common in men over age 50. Two recent studies, in the Journal of the American Medical Association and Urology, have confirmed the benefits of saw palmetto. ,
Cautions: In rare instances, saw palmetto may upset the stomach.
Dosage: 160 mg twice daily.
Hot Tips: If you're around age 50, consider taking saw palmetto to prevent prostate enlargement. Take it with food.
Detoxifier: Milk Thistle
Research: Silymarin, the antioxidant complex extracted from milk thistle, exerts many of its benefit effects on the liver, the body's chemical processing organ. In Europe, it is used to treat cirrhosis and alcoholic liver disease. One recent study found it to improve glucose control in diabetes.
Cautions: Silymarin is free of side effects.
Dosage: 150-600 mg daily.
Hot Tips: Many people take silymarin or milk thistle as a "tonic" or anti-stress supplement.
Beautiful Skin: Chamomile
Research: This gentle herb is a traditional European remedy for upset stomach. Considerable research shows that, used topically, it helps condition the skin.
Cautions: People with hayfever may cross-react to chamomile.
Dosage: 200-400 mg daily.
Hot Tips: For upset stomach, brew a cup of chamomile tea, which is available in teabags. For skin, look for cosmetic products that use chamomile.
Restful Sleep: Valerian
Research: Valerian is a natural sedative commonly used in Europe to treat insomnia and other sleep disorders. As a testament to its effectiveness, more than 80 sleep remedies in the United Kingdom contain valerian. It can also be used to treat general anxiety and restlessness.
Cautions: If you take valerian and drive, watch for signs of drowsiness.
Dosage: 150-400 mg nightly.
Hot Tips: Valerian has an awful odor, so capsules and tinctures may be the preferred forms.
The information provided by Jack Challem and The Nutrition Reporter™ newsletter is strictly educational and not intended as medical advice. For diagnosis and treatment, consult your physician.