Uprooting herbal myths
Uprooting Herbal Myths
From Consumers Union
The notion of herbal remedies once evoked images of faraway lands, mystical healers and exotic shops scented with incense. But today, herbal products are moving headlong into the mainstream.
Bayer Corporation, maker of Bayer Aspirin and One-A-Day vitamins, is launching a line of One-A-Day Specialized Supplements, which combine herbs with vitamins or minerals. Other corporate giants, including American Home Products, SmithKline Beecham, and Warner-Lambert, have their own herbal-supplement lines either in the works or already on the shelves.
And the products won't be tucked away in some obscure corner of the local health-food store; they'll be sold in supermarkets, large retail chains, and major drugstores, right alongside the conventional over-the-counter drugs.
The herbal-image makeover stems partly from recent research showing that some remedies - such as feverfew for migraine, ginger for nausea, saw palmetto for symptoms of prostate enlargement and St. John's-wort for minor depression - may indeed be, at least, mildly effective. Those findings help dispel one myth about herbal remedies: that they're all based on nothing more than folklore or Eastern traditions, with little or no scientific support.
But the upgraded image of herbal remedies may help perpetuate the opposite - and potentially more harmful - type of misconception, which glorifies herbs, overstates their benefits and obscures their possible risks.
Here are six such myths.
Myth:
Herbs are natural, so they must be safe and effective.
Truth:
"Natural" is hardly synonymous with "safe"--just think of hemlock or poisonous mushrooms. And while most herbal remedies are believed to be benign, at least in the short run, there are numerous exceptions.
Probably all herbs have the potential to cause allergic reactions, and many herbs can produce side effects, such as stomach upset or diarrhea from saw palmetto or feverfew. Overdosing or overuse can lead to greater danger. Taking high doses of ephedra (ma huang), for example, can cause high blood pressure, heart palpitations, stroke, seizure, and even death. Taking licorice or cascara sagrada bark for more than a few weeks can deplete potassium levels and, in turn, cause muscle weakness and potentially deadly heart-rhythm irregularities. Moreover, certain herbs can harm people with certain diseases, or interact dangerously with conventional drugs.
Some herbal products may be contaminated with pesticides or toxic chemicals, such as arsenic, mercury and lead; that's most often found in chopped-plant products and various Asian remedies. Other herbal products, usually pills or extracts, may be illegally spiked with potentially harmful prescription drugs, including steroids and diazepam (Valium).
"Natural" is not synonymous with "effective," either. Herb enthusiasts claim that the multiple compounds in plant remedies work in a synergistic, or mutually enhancing way, and that "natural" compounds are absorbed more readily than synthetic ones. But while herbs do contain numerous compounds, their effect often stems from a single active ingredient - such as kawain for the calming effect of kava kava, or capsaicin for the pain-relieving effect of hot pepper. Moreover, the body can't tell whether the compound comes straight from a plant or is synthesized in a lab.
Once scientists replicate the chemical structure of a "natural" substance, the copy has exactly the same effect on the body. For example, salicin and its synthetic twin salicylic acid, the active ingredient in early aspirin-like products, are equally effective, both for headaches and for inflammation. Acetylsalicylic acid - a derivative developed to reduce side effects and used today in all aspirin products - also works equally well. However, you'd have to drink about 10 cups of white-willow-bark tea or take dozens of capsules before you'd get enough salicin to equal the amount of acetylsalicylic acid in a single standard aspirin tablet.
Myth:
Herbs must be safe and effective because they've been used for thousands of years.
Truth:
Traditional healers never knew about the risks of many herbs, for two reasons. Certain health problems -- such as cancer caused by chemicals in borage, coltsfoot, comfrey, life root and sassafras root -- may not show up for years, so it's hard to pin them on the herb without a long-term study. Other serious problems occur too infrequently to be noticed except by a large study or by gathering numerous isolated case reports.
As for effectiveness, people have used such herbs as alfalfa, chaparral, goldenseal, pennyroyal and yucca for centuries. But modern research has debunked many of their purported benefits -- and confirmed none of them.
Myth:
You don't need to tell your doctor you're taking herbs.
Truth:
In one survey, three out of four people who took herbal supplements said that they never told their doctor. That's unwise.
Adverse reactions to herbs may go undiagnosed -- and mistreated -- if your doctor doesn't know what you're taking. That's particularly worrisome for people who have a chronic disease. For example, echinacea may aggravate rheumatoid arthritis or other disorders caused by misdirected immune activity; eleuthero may send blood pressure soaring in people with hypertension; and devil's claw root may make gastric or duodenal ulcers worse.
Further, some herbs may interact harmfully with the drugs your doctor prescribes. Herbal laxatives such as flaxseed, guar gum and psyllium can slow the absorption of most medications. Garlic, ginger and ginkgo biloba may inhibit clotting, which could cause excessive bleeding if you're taking other, more powerful blood thinners such as aspirin or warfarin (Coumadin). And ginseng and gotu kola may lower blood sugar excessively in people taking conventional diabetic drugs to control sugar levels.
Myth:
If the label says an herb works, there must be some scientific evidence that it does.
Truth:
The label for one saw palmetto supplement says it "promotes prostate and urinary well-being." Another, for goldenseal, says it helps "reduce inflammation of mucous membranes." Most makers of herbal products now make such claims - and they almost never have to provide any proof.
Since passage of the Dietary Supplement Health and Education Act of 1994, the Food and Drug Administration has had to allow such unproven claims, provided the label describes only how the product affects the body's "structure or function," rather than promising to treat or prevent any disease. Of course, men wouldn't care about their "urinary well-being" if they weren't really hoping to treat symptoms of an enlarged prostate; nor would people care about "inflammation of mucous membranes" if they didn't have a head cold. While the maker is supposed to have some substantiation for the claims, the FDA rarely asks to see it.
Myth:
All products that say they contain a particular herb are essentially the same.
Truth:
The same herb often comes in several different forms: a tea, an alcohol-and-water tincture, a pill, even a patch. But not all forms produce the same effects. Tea made from saw palmetto probably has no health benefits, since the active compounds don't dissolve in water. And while the active chemical in ginkgo, white willow bark or milk thistle does dissolve, even the strongest tea is probably too weak to do any good.
Further, different parts of the same herb can have different effects. Dandelion leaves may act as a diuretic, the roots as a laxative. While the Chinese eat ginkgo seeds, only ginkgo leaves contain the active compounds -- and only processed ginkgo leaves are safe to take internally. And sassafras remedies are made from the root, the one part of the plant that's potentially carcinogenic.
Finally, the potency and purity of individual plants can differ appreciably, depending on how and where they're grown and how they're stored and handled.
More and more manufacturers are trying to standardize their products by combining batches and isolating the active compounds. But manufacturers often disagree on which ingredients to include and what dose to use. Analyses of ginseng and St. John's-wort products have found radically different amounts of the active ingredients in different brands. And it's often impossible to spot the difference, since manufacturers are required to list only the plant and the part used, not the name or amount of the supposedly active ingredient. Even if they did list it, there's no guarantee you'd get what the label says, since no government agency or other independent group monitors the potency and purity of herbal products.
Myth:
There's not much you need to know about how to take herbs.
Truth:
All conventional medications are sold in standardized doses and provide information about the appropriate use, side effects and precautions. Moreover, prescription drugs are taken under a doctor's guidance.
There are no such safeguards in the largely unregulated herbal jungle. So you may need to know even more about herbal remedies than you do about medications. Unfortunately, information about herbs can be just as unreliable as their quality.
Summing up
While some studies have suggested that certain herbs may be beneficial, romanticizing all "natural" remedies and ignoring their potential risks can lead to disappointing - or dangerous-results. Herbs can cause allergic reactions, side effects, and drug interactions, especially if you take too much of the herb or use it for too long. And because herbal remedies are virtually unregulated, you can't rely on their potency or purity – or on the claims made on the label. To use herbs as safely and effectively as possible:
- Tell your doctor about any herbal remedies - and any other dietary supplements or nonprescription drugs - that you take.
- Consult your doctor before taking herbal remedies if you have a chronic disease or if you are taking medications.
- Avoid herbal remedies if you're pregnant, may become pregnant or are breast-feeding; give them to children only under a doctor's supervision.
- Consult a reliable source of information about dosages and precautions.
- If you suspect a problem, stop immediately and call your doctor.
- To report adverse effects, contact the FDA's MedWatch program (see "For more information," below).
For more information
Herbs of Choice, by Varro Tyler, Ph.D. Haworth Press, 1994. $39.95, hardcover; $14.95, softcover. Call 800-342-9678. An update,
Tyler's Herbs of Choice, prepared by James Robbers, Ph.D., may be available for $49.95 (hardcover) by the end of the year.
American Herbal Products Association's Botanical Safety Handbook. $39.95. Call CRC Press at 800-272-7737. World Health Organization. Comprehensive reports on 28 herbs. Price and publication date not yet determined, but should be available by the end of this year or early next year. Call 518-436-9686. (E-mail: qcorp@compuserve.com)
The U.S. Pharmacopeia (USP). Free fact sheets on a few common herbs; comprehensive reports for $25 each. Material on more herbs may be available soon. Call 301-816-8223. (www.usp.org/did/mgraphs/botanica/index.htm)
FDA MedWatch monitoring program. To report adverse effects, call 800-FDA-1088. (www.fda.gov/medwatch/report/consumer/consumer.htm)
Copyright © Consumers Union of U.S., Inc., 1999
Back to Top
Table of Contents for This Section
