Herbal Tea - Medicinal Concerns

Medicinal Concerns

See also: List of herbs with known adverse effects

Tisanes are often consumed for their physical or medicinal effects, especially for their stimulant, relaxant or sedative properties. The medicinal effects of certain herbs are discussed under herbalism. The medicinal benefits of specific herbs are often anecdotal or controversial, and in some countries (including the United States) makers of tisanes are not allowed to make unsubstantiated claims about the medicinal effects of their products.

While most tisanes are safe for regular consumption, some herbs have toxic or allergenic effects. Among the greatest causes of concern are:

• Comfrey, which contains alkaloids that can cause permanent liver damage with chronic use.
• Lobelia, which contains toxins similar in effect to nicotine.

Tisanes can also have different effects from person to person, and this is further compounded by the problem of potential misidentification. The deadly foxglove, for example, can be mistaken for the much more benign (but still relatively toxic to the liver) comfrey.

The UK does not require herb teas to have any evidence concerning their efficacy, but does treat them technically as food products and require that they are safe for consumption.

Most of the ingredients used in Indian tisanes are non-toxic in nature. However, according to Naithani & Kakkar (2004), "all herbal preparations should be checked for toxic chemical residues to allay consumer fears of exposure to known neuro-toxicant pesticides and to aid in promoting global acceptance of these products".

Depending on the source of the herbal ingredients, teas may be contaminated with pesticides or heavy metals.