The botanical definition of a herb is any seed-bearing plant that does not have a woody stem and dies down to the ground after flowering. Throughout history, herbs have been used to prevent and treat disease. Herbs were once considered a part of folklore but today they are more popular than ever. It is estimated that about one in six Americans uses herbs to treat illness or boost health. The six most popular herbal medicinal products in the U.S. today are: ginkgo biloba , St. John’s wort, ginseng, echinacea, saw palmetto, and kava.
Ginkgo Biloba is also called “maidenhair.” Today it is marketed to enhance memory and to treat some circulatory diseases. Supplements have not been found to reduce the incidence of dementia or protect against cognitive decline in older patients. However, there is some evidence that it may benefit mood and attention in healthy adults.
Side effects can include GI distress, headache, dizziness, and allergic skin reactions. It also can cause bleeding, when combined with warfarin or aspirin, elevated blood pressure when combined with a thiazide diuretic and coma when combined with the antidepressant trazodon
St. John’s Wort is claimed to promote mental well-being since it does contain low doses of the chemical found in Prozac. The results of clinical trials suggest that it is effective for the treatment of depression. Side effects include sensitivity to sunlight, anxiety, dry mouth, dizziness, GI symptoms, fatigue, headache, sexual dysfunction, interactions with antidepressants, birth control pills, digoxin, warfarin, and seizure-control drugs, antibiotics, immunosuppressants, and HIV medications.
Ginseng today is popular for its effects on cardiovascular health, the central nervous system, endocrine function, and sexual function,. However, controlled trials have been questionable when investigating other claims of immune system benefits, lowering of blood glucose and blood pressure. It may not be safe for those taking warfarin and has been found to interact with other medications such as estrogens, corticosteroids, antidepressants, and morphine. Side effects include diarrhea, headache, and insomnia.
Echinacea is known for its claim to treat colds, flu and infections. It is hypothesized to act as an immune system stimulant, but there is little evidence that it is beneficial in either preventing or treating the common cold. Very few side effects have been reported, but allergies are possible.
Saw Palmetto today is marketed to treat prostate enlargement and therefore improve urinary flow. There is some evidence of its effectiveness with mild to moderate improvement in urinary symptoms and flow measures; however, other trials report no improvement. There appears to be no drug interactions and only mild side effects of abdominal pain, decreased libido, headache, fatigue, nausea, and rhinitis.
Kava is marketed today to relieve stress and anxiety. A review of the effectiveness concluded that administration is effective in reducing anxiety. However, using this herb may not be the safest way to relieve stress. In 2002 the FDA issued a warning about kava since it may cause liver damage, including hepatitis, cirrhosis, and liver failure. It has been taken off the market in many European countries and in Canada, Australia, and Singapore.
Things to consider when taking any herbal product:
- If you are taking other medications, consult your physician before taking herbs.
- Do not take any herbal supplement for two weeks before surgery.
- Do not take herbs if you are pregnant.
- Do not give herbs to children in any form.
- Do not assume herbal products are safe; many can be toxic.
- Read the label ingredients and the list of precautions.
- Start with low doses and immediately stop if side effects occur.
- Do not take combinations of herbs.
- Do not use herbs for long periods of time.
SOURCE: Smolin, Lori A, Grosvenor, Mary B. Nutrition: Science and Applicatons Third Edition. Wiley, 2013.