Bitter herbs are fundamental to Phytotherapy's contribution to holistic medicine. They are quite simply herbs that have a bitter taste, ranging from mildly bitter Yarrow to fiercely bitter Rue. Absinthin, a constituent found in Wormwood, is so bitter it can be tasted at dilution's of 1 part in 30, 000 parts of water. The bitterness is often described as being due to a 'bitter principle', but this may be a volatile oil, an alkaloid, iridoid or a sesquiterpene.
A range of physiological responses occur following stimulation of the bitter receptors of the tongue. The taste of bitterness, and no doubt many subtleties of which we are consciously unaware, is transmitted by specific taste buds at the back of the tongue to the central nervous system, triggering a number of reflexes. These reflexes have important ramifications, all of value to the digestive process and general bodily health:
- There is a stimulation of the flow of digestive juices from the exocrine glands of mouth, stomach, pancreas, duodenum and liver, aiding in good digestion of food as well as a range of conditions that have their basis in efficient or allergy distorted digestion.
- Because of this flow of digestive juices there will be an accompanying stimulation of appetite. This is helpful in convalescence as well as problems where there is a reduction of appetite. Unfortunately appetite stimulation is not always desirable!
- The bitters are thought to stimulate a range of liver activities, especially increasing the production of bile, and the release of bile from the gallbladder.
- There is a very mild stimulation of endocrine activities, especially insulin and glucagon secretion by the Islets of Langerhans in the pancreas. Thus diabetics need to take care with bitters as they may change their blood sugar balance. In the hands of a skilled practitioner, however, such remedies may have a role to play in the treatment of non-insulin dependent diabetes.
- Herbalists have long known of the subtle psychological effects of bitter remedies and in some cases bitters may act in an anti-depressant way, for example in post-viral infection depression.
- Through the central reflex there is a stimulation of peristalsis in the tubular muscles of the body.
- The bitters help the gut wall repair damage through stimulating the self-repair mechanisms.
The therapeutic implications of bitters are impressive as the tonic effects go beyond the specifics of digestive hormone activity. As digestion and assimilation of food is fundamental to health, bitter stimulation may improve a condition that has nothing pathologically to do with the digestive process.
There is much overlap in practice between the bitters and tonic remedies, the mechanism of action is not always clear, but it is evident that these herbs act to promote health - yet another wonderful gift of nature.
Bitter stimulation effects are shared by any herb that can trigger the receptor sites on the tongue, but selection of appropriate bitter can be made by considering their inherent strength, other actions and specific indications.
Commonly used Herbal Bitters
Relative intensity of Herbal Bitters
The strength of an action effect is not particularly relevant in the case of bitters, instead a subjective measure of taste intensity approximates more to the degree of physiological response a bitter herb might generate. Thus we can identify 'mild' and 'strong' bitters, but to the bitter neophyte they may all seem too much!
Bitters that are also Anti-Catarrhal : Boneset, Centaury, Golden Seal, Horehound, Yarrow
Bitters that are also Anti-Inflammatory : Chamomile, Golden Seal, Wormwood, Yarrow
Bitters that are also Anti-Microbial : Chamomile, Golden Seal, Mugwort, Southernwood, Wormwood, Yarrow
Bitters that are also Anti-Spasmodic : Chamomile, Rue, White Horehound
Bitters that are also Astringent : Golden Seal, Yarrow
Bitters that are also Carminative: Centaury, Chamomile, Southernwood, Tansy, Wormwood
Bitters that are also Cholagogue : Barberry, Centaury, Gentian, Golden Seal, Mugwort, Southernwood, Tansy, Wormwood
Bitters that are also Demulcent :
Bitters that are also Diaphoretic : Boneset, Yarrow
Bitters that are also Diuretic : Yarrow
Bitters that are also Emmenagogue : Centaury, Gentian, Golden Seal, Mugwort, Rue, Southernwood, Tansy, Wormwood, Yarrow
Bitters that are also Expectorant : Rue, Horehound
Bitters that are also Hepatic : Barberry, Centaury, Gentian, Golden Seal, Mugwort, Rue, Southernwood, Tansy, Wormwood, Yarrow
Bitters that are also Laxative : Barberry, Boneset, Centaury, Gentian, Golden Seal
Bitters that are also Nervine : Centaury, Chamomile, Mugwort
Bitters that are also Tonic : Centaury, Golden Seal, Mugwort, Rue, Horehound, Wormwood, Yarrow
Bitters that are also Vulnerary : Chamomile, Golden Seal, Horehound, Yarrow