Blueberry

Botanical name: Vaccinium spp.

Blueberry.jpg

© Steven Foster

Parts used and where grown

Blueberry is closely related to the European bilberry (Vaccinium myrtillus). Several species of blueberries exist—including V. pallidum and V. corymbosum—and grow throughout the United States. Blueberry leaves are the primary part of the plant used medicinally. However, the berries are occasionally used.

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

Rating Health Concerns
1Star

Common cold/sore throat

Diarrhoea

Urinary tract infection
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)

According to traditional herbal textbooks, a tea made from blueberry leaves was considered helpful in diabetes, urinary tract infections, and poor appetite.1 The berries were a prized commodity among the indigenous peoples of North America.

Active constituents

Tannins make up as much as 10% of blueberry leaves. The astringent nature of tannins likely accounts for the usefulness of blueberry leaf in treating diarrhoea.2 The astringent effect may also be soothing for sore throats.3 Bilberry, blueberry’s European cousin, is used primarily for maintaining blood vessels, particularly those in the eyes. Some preliminary evidence indicates that anthocyanosides, the bioflavonoid complex common to bilberrry and blueberry may help people with diabetes, particularly if they have damage to the retina (retinopathy). However, these studies are primarily based on a standardized extract from bilberry fruit.4

How much is usually taken?

A tea is prepared by combining 1 cup (250 ml) boiling water and 1–2 teaspoons (5–10 grams) of dried leaves and steeping for 15 minutes. As many as 6 cups (1,500 ml) each day may be taken for diarrhoea and 3 cups (750 ml) each day for diabetes. Alternatively, 1 teaspoon (5 ml) of tincture can also be used three times per day.

Are there any side effects or interactions?

If the tea does not significantly reduce diarrhoea within two to three days, consult with a healthcare practitioner. Fresh (but not dried) berries tend to be laxative and should be avoided in cases of diarrhoea.5

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

References

1. Tilford GL. Edible and Medicinal Plants of the West. Missoula, MT: Mountain Press Publishing Company, 1997, 80–1.

2. Tyler V. Herbs of Choice: The Therapeutic Use of Phytomedicinals. New York: Pharmaceutical Products Press, 1994, 52–4.

3. Schilcher H. Phytotherapy in Paediatrics. Stuttgart, Germany: Medpharm Scientific Publishers, 1997, 126–7.

4. Passariello N, Bisesti V, Sgambato S. Influence of anthocyanosides on the microcirculation and lipid picture in diabetic and dyslipic subjects. Gazz Med Ital 1979;138:563–6.

5. Tyler V. Herbs of Choice: The Therapeutic Use of Phytomedicinals. New York: Pharmaceutical Products Press, 1994, 52–4.