Fortunately, a 512-page scientific evaluation of herbal supplements, The ABC Clinical Guide to Herbs, was just published by the American Botanical Council, a non-profit education and research group to which I belong. Although intended as a reference book for doctors and other health professionals, it's rich in facts for consumers, too.
Mark Blumenthal, the book's editor and executive director of the council, helped me review the five best-selling herbs. Bottom line: Each remedy can work--but perhaps not in the way you think it does!
1. Gingko biloba
Why take it? To improve short-term memory and cognitive functioning in older people and those with dementia and early Alzheimer's disease, and to relieve leg pain due to poor circulation (a condition called intermittent claudication). Ginkgo improved memory and concentration in healthy adults in some studies, but not others, so the benefits are unclear.
How safe? Adverse effects are rare and usually mild, such as gastrointestinal upset. Theoretically, ginkgo might interact with anticoagulants, such as aspirin and coumadin, to promote bleeding. To be safe, consult a doctor before mixing ginkgo and anticoagulants, and avoid ginkgo if you are allergic to it, have a bleeding disorder or will undergo surgery within a week.
How much? 120mg to 240mg daily, divided into two or three doses, for memory loss and dementia. 120mg to 160mg daily, divided into two or three doses, for leg pain.
Most-tested brands: Ginkgold, Ginkoba, Ginkai.
2. Garlic supplements
Why take them? To help prevent or reverse cardiovascular disease. Garlic can fight arterial plaque, improve the elasticity of arteries, reduce blood clotting, and slightly lower cholesterol, triglycerides and high blood pressure. Best evidence: In a German study of 152 subjects with significant plaque buildup, taking 900mg garlic powder tablets a day for four years caused plaque to shrink 2.6%. Plaque increased 15.6% in non-garlic takers.
How safe? Side effects include allergic reaction, upset stomach and increased blood-clotting time. Taking with aspirin or coumadin might increase chances of prolonged bleeding. Avoid garlic for at least one week pre-surgery.
How much? Garlic powder (standardized): 200mg to 300mg, three times daily. AGE (aged garlic extract): 300mg to 800mg, three times daily.
Most-tested brands: Kwai, Kyolic.
3. Echinacea
Why take it? To help reduce cold and flu symptoms. Studies show it can cut days off those illnesses by 30% to 40%. Some people take echinacea regularly, hoping to prevent colds and flu, but there's no scientific evidence it works.
How safe? Extremely safe. Rare allergic reactions. No known drug interactions. Some people caution against using echinacea if you have an autoimmune disease, such as lupus or HIV, but there are no known cases of harm.
How much? Juice: 6ml to 9ml daily. Tincture: five drops, one to three times daily. Or follow package directions.
Most-tested brands: Echinaguard, Echinaforce.
4. Saw palmetto
Why take it? To reduce non-malignant enlargement of the prostate gland or benign prostatic hyperplasia (BPH) in men over age 50. Evidence is compelling that saw palmetto improves urine flow and lessens the need to urinate at night. New studies show it shrinks prostate tissue and lowers levels of the hormone associated with BPH. In studies, it worked as well as the leading prescription drug, with 90% fewer side effects.
How safe? Extremely safe. Gastrointestinal disturbance and other mild problems hit 2% of users. No known drug interactions. Do not take saw palmetto without first getting a diagnosis of prostate trouble from a health professional.
How much? Extract: 160mg twice daily, or 320mg once daily.
Most-tested brand: Prostactive.
5. Asian ginseng (Panax ginseng)
Why take it? To stimulate immune functioning and boost disease resistance. "That's why I take ginseng," Blumenthal says. Most people who take it are hoping for increased athletic performance, endurance and energy, but unfortunately, tests don't support those claims. Other research shows American ginseng (Panax quinquefolius) can help maintain normal blood sugar levels in Type 2 diabetics.
How safe? No adverse effects are known. If you take coumadin, zidovudine (an HIV drug) or phenelzine (an anti-depressant), consult a doctor before taking ginseng. Diabetics may need to adjust insulin dosages.
How much? Two 100mg capsules daily, standardized to 4% ginsenosides.
Most-tested brand: Ginsana.
Smart ways to buy and use any herbal supplement: Buy from a reliable source.
- Buy a brand that says "standardized" on the label; this means the product has a fixed percentage of specific compounds.
Read labels carefully and follow directions for doses, usage, storage and other precautions.
- Tell your doctor which supplements and medications you are taking; interactions could occur.
- If you notice any adverse effects, consult a doctor.
The ABC Clinical Guide to Herbs (American Botanical Council, $49.95) is available
at herbalgram.org or 800-373-7105.
This book can be used for continuing education credits for health professionals.
Copyright 2004 Jean Carper. Printed first in USA Weekend. All rights reserved.
For more information from Jean Carper, go to www.jeancarper.com
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