Herbal tea


Herbal teas or herb teas, technically known as herbal infusions, and less commonly called tisanes, are beverages made from the infusion or decoction of any herbs, spices, or other plant material in water that is not derived from the tea plant. Many herbs used in teas/tisanes are also used in herbal medicine and in folk medicine. Herbal teas are not technically teas because they are not brewed from the tea plant.
The term "herbal tea" is often used to distinguish these infusions from true teas, which are prepared from the tea plant or, more rarely, its close relatives . Beverages actually created from tea and combined with material from other plants are known as "blended teas", "scented teas", or "flavored teas". Examples include jasmine tea, genmaicha, and Earl Grey tea. Unlike true teas, most tisanes do not naturally contain caffeine.
A number of plants, however, do contain psychoactive compounds, such as caffeine or another stimulant, like theobromine, cocaine or ephedrine. Some have the opposite effect, acting as a sedative. Some common infusions have specific names such as [Mate (drink)|mate] and rooibos.

Etymology

Dictionaries commonly record that the word tea is used to refer to other plants beside the tea plant and to beverages made from these other plants. The term herbal tea is well established and more common than tisane for this usage
Furthermore, in the Etymology of tea, the most ancient term for tea was 荼 which originally referred to various plants such as sow thistle, chicory, or smartweed, and was later used to exclusively refer to Camellia sinensis.
The word tisane was rare in its modern sense before the 20th century, when it was borrowed in the modern sense from French. This is why some people feel it should be pronounced as in French, but the original English pronunciation continues to be more common in US English and especially in UK English.
The word had already existed in late Middle English in the sense of "medicinal drink" and had already been borrowed from French. The Old French word came from the Latin word ptisana, which came from the Ancient Greek word πτισάνη, which meant "peeled" barley, in other words pearl barley, and a drink made from this that is similar to modern barley water.

Composition and usage

Herbal teas can be made with any part of a plant, including fresh or dried flowers, fruit, leaves, stems, seeds, or roots. These parts may be steeped fully raw or processed in some way.
Herbal infusions may be made by pouring hot or boiling water over the plant parts and letting them steep for some time. The infusion temperature and time can vary depending on the type of plant part used and its properties. For example, some plant parts are covered in oils, which may take some time to separate. Brewing with cold water will also take much longer, usually several hours.
An herbal tea may be strained or not.
Some herbal teas are blends that include various herbs or plant parts. Herbal infusions may also be sweetened, spiced, salted, or combined with other additives, like milk or lemon juice.

Varieties

Herbal teas can be made from any edible plant material, below is a list of common herbal infusions. Some herbal teas are made from plants which contain caffeine, and other herbal infusions may contain other psychoactive compounds. However, many other common herbal teas have not been shown psychoactive properties when compared to placebos, though they may still have some physical effects.
Many herbal teas on the market may also be blends which include various herbs or plant parts. These blends may also include additives, like flavorings.

Caffeinated infusions

Other psychoactive infusions

Non-caffeinated and non-psychoactive infusions

Health risks

While most herbal teas are safe for regular consumption, some herbs have toxic or allergenic effects. Among the greatest causes of concern are:
Herbal teas 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 comfrey. Care must be taken not to use any poisonous plants.
The US does not require herbal teas to have any evidence concerning their efficacy, but does treat them technically as food products and require that they be safe for consumption.
Fruit or fruit-flavored tea is usually acidic and thus may contribute to erosion of tooth enamel.

Adverse herb–drug interactions

Some phytochemicals found in herbs and fruits can adversely interact with others and over the counter or prescription medications, among other ways by affecting their metabolism by the body. Herbs and fruits that inhibit or induce the body's Cytochrome P450 enzyme complex function can either cause the drug to be dangerously ineffective, or increase its effective absorbed dose to potentially toxic levels, respectively. Best known examples of adverse herb‑drug interactions are grapefruit or St John's wort, contraindicated for several medications including Paxlovid and oral contraceptives, but other herbs also affect the CYP enzyme family, showing herb‑drug interactions.

Contamination

Depending on the source of the herbal ingredients, herbal teas, like any crop, may be contaminated with pesticides or heavy metals.
According to Naithani & Kakkar, "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".