Blessed Thistle

Common name: St. Benedict Thistle

Botanical name: Cnicus benedictus

Photo

© Steven Foster

Parts used and where grown

Although native to Europe and Asia, blessed thistle is now cultivated in many areas of the world, including the United States. The leaves, stems, and flowers are all used in herbal preparations.

Blessed thistle has been used in connection with the following conditions (refer to the individual health concern for complete information):

Science Ratings Health Concerns
1Star

Indigestion and heartburn

Poor appetite
3Stars Reliable and relatively consistent scientific data showing a substantial health benefit.
2Stars Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
1Star For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support and/or minimal health benefit.

Historical or traditional use (may or may not be supported by scientific studies)

Folk medicine used blessed thistle tea for digestive problems, including gas, constipation, and stomach upset. This herb was also used—like its well-known relative, milk thistle1 —for liver and gallbladder diseases.

Active constituents

The sesquiterpene lactones, such as cnicin, provide the main beneficial effects of blessed thistle in the treatment of indigestion. The bitterness of these compounds stimulates digestive activity, including the flow of saliva and secretion of gastric juice, which leads to improved appetite and digestion.2 Some pharmacological evidence suggests that blessed thistle may also have anti-inflammatory properties.3

How much is usually taken?

The German Commission E monograph recommends 4–6 grams of blessed thistle per day.4 Alternatively, tincture (1/2 teaspoon [2 ml] three times per day) may be used. Approximately 1/2 teaspoon (2 grams) of the dried herb can also be added to 1 cup (250 ml) of boiling water and steeped 10 to 15 minutes to make a tea. Three cups can be drunk each day.

Are there any side effects or interactions?

Blessed thistle is generally safe and is not associated with side effects. Anyone with allergies to plants in the daisy family should use blessed thistle cautiously.

At the time of writing, there were no well-known drug interactions with blessed thistle.

References

1. Lust JB. The Herb Book. New York: Bantam Books, 1974, 343.

2. Bradley PR (ed). British Herbal Compendium, vol 1. Bournemouth, Dorset, UK: British Herbal Medicine Association, 1992, 126–7.

3. Foster S. 101 Medicinal Herbs. Loveland, CO: Interweave Press, 1998, 32–3.

4. Blumenthal M, Busse WR, Goldberg A, et al. (eds). The Complete Commission E Monographs: Therapeutic Guide to Herbal Medicines. Boston, MA: Integrative Medicine Communications, 1998, 92.