Tell me about herbs and herbal products
Herbs have been important contributors to the quality of human life for thousands of years. Throughout history plants have served mankind as valuable components of seasonings, teas, cosmetics, dyes and medicines. The term herbs is used to refer not only to herbaceous plants but also to bark, roots, leaves, seeds, flowers and fruit of trees, shrubs and woody vines. 

Recently there has been a resurgence of interest in the use of herbs. Various herbal teas are used in place of caffeine-containing beverages. Dietary recommendations encourage the use of herbal seasonings to flavor food as a way to cut down on the use of table salt. In the following table, there is listed a number of herbs that can be safely used to season food. 

Medical Herbs
There are a number of other herbs, containing active constituents, which may provide useful and healing relief and healing when used in a discriminatory fashion. Chamomile is known for its anti-inflammatory activity; Echinacea for its stimulation of the immune system and providing help for coughs and colds;use of feverfew helps decrease the frequency and severity of migraine headaches; garlic acts as a wide-spectrum antibiotic as well as lowering blood cholesterol levels, reducing blood clots and providing anti-cancer properties; ginger
prevents nausea and motion sickness; gingko improves cerebral flow; peppermint helps resolve irritable bowel syndrome; St. John's wort is a natural anti-depressant; and valerian acts as milk tranquillizer. So as to monitor the safety and efficiency of any herbal preparations, one should purchase herbs in which the active medical agent is guaranteed to be standardized. 

Some view herbal products as natural remedies for the treatment of varied disorders and illness. Self-prescribed herbal preparations are widely used for a whole host of common conditions including insomnia, arthritis, colds, coughs, ulcers, allergies, constipation, infections, high blood pressure, intestinal disorders, premenstrual syndrome, headaches, fever, anemia, weakness, aging, stress, nervousness, sexual disorders, and indigestion. Not all self-prescribed herbal use is justified, safe and reliable. 

Questionable Products
A number of herbal products, such as aloe vera, blue-green manna and bee pollen, have been promoted as possessing special healing and health-promoting properties. One should always be wary of products that are sold as cure-alls, miracle food supplements or panaceas. While the fresh juice of aloe vera may promote wound healing when applied externally, the commercial gels, ointments and creams containing aloe vera have no therapeutic value at all, since the active properties of the fresh juice are unstable and cannot be retained over
time. Furthermore, experiments are unable to verify that blue-green manna (an algae) has any significant health-promoting properties. Likewise, it has not been proven that bee pollen has any valid use as a general tonic, or that it can help in weight reduction, stop premature aging or serve to improve one's athletic performance. 

Are there any health hazards?
Some of the herbs sold today are safe and may have some therapeutic benefits, while others may have no measurable effects. Still others may be toxic and dangerous (see the following table). Over the past decade more than 30 herbal teas have been found to contain substances that cause serious toxicities- including disorders of the liver, nervous system, gastrointestinal tract, as well as blood disorders. 

A number of deaths have been reported after using certain herbal teas. These include pokeweed, oleander, and pennyroyal. Since manufacturers are not required to list potential toxicities on the label, consumers may be exposed to dangerous substances. 

The Food and Drug Administration has expressed concern about the safety of some herbal products and believes that consumers need to be protected from the potential hazards of some herbs. Herbal preparations may contain substances other than the ones declared in the label. For example, ginseng and other herbs have been found to be "spiked" or contaminated with synthetic products and even some common drugs, so as to provide a desired property or stimulatory action. Inadequate labeling and poor standardization of contents is commonly seen with
herbal teas. These practices can contribute to the risk of overdose and toxicity. 

 Furthermore, a number of commonly used herbal teas may be cancer forming, since they contain substances which have been shown to cause tumors in laboratory animals. The list of suspect teas includes those made from bayberry, calamus, coltsfoot, comfrey, and sassafras. 

A number of herbal teas have been shown to contain psychoactive substances. Those producing adverse neurological effects, including hallucinations, are mandrake, nutmeg, periwinkle, yohimbe, lobelia, thornapple (jimsonweed). In addition guarana and mate have a stimulatory effect due to the high levels of caffeine they contain. 

Since many herb teas are rich in tannins, they can bind to drugs and certain vitamins and minerals. This means that there will be a decreased absorption of some essential nutrients as well as decreased effectiveness of some administered medications. 

The potency of herbal beverages, and hence their effectiveness, cannot be accurately predicted since the concentration of active ingredients in the plant material can vary enormously. In addition, people's reaction to a given herb can vary greatly. Since there can be a wide variation of biological activity possible in a particular herb, the desired effect sought after may or may not be obtained. This could lead to the use of stronger brews, which may prove to be dangerous. 

All of the hazardous effects that have been described for the use of herbal teas also applies to the use of powders, pills and capsules that are composed of the same materials found in the teas. Using an herbal product to treat a serious health condition is dangerous and is not recommended. In such a case, safe and proper medical help could be delayed unnecessarily. 

Are there any guidelines I might follow?

1. Refrain from considering herbal beverages as natural panaceas. 

2. Be alert to the toxicities of certain herbs. 

3. Avoid buying unlabeled "loose" or bulk teas. 

4. Read labels carefully, so that only prepackaged teas with safe ingredients are used. 

5. Use moderate amounts of those teas with safe and effective constituents. 

6. Drink no more than 1-2 cups of tea per day on a regular basis, since the long term effects of drinking most herbal teas in large quantities is not known. 

7. People who show allergic response to ragweed, asters, or chrysanthemums should avoid all teas containing marigold, yarrow and chamomile flowers. 

8. Pregnant women should especially use caution in drinking any herbal tea since few have been thoroughly tested for safety. Before using any herbal tea, a pregnant woman should first consult with her physician.
Likewise young children should be restricted in their use of herbal teas.