Raspberry (Rubus ideaeus) is a deciduous bush from the Rosaceae family that grows up to 6 ft (2 m) high, with erect and thorny stems, a thin spine and perennial roots. The bush is well-known for its fruit, a red spherical berry that grows continuously on the branches. Cymes (clusters) of white flowers bloom in late spring to early summer. Raspberries can be grown in many temperate countries, in either dry or moist wooded areas.
Raspberry leaves are used as an astringent and stimulant. High concentrations of tannin found in the plant are the source of its astringent effects. It also contains flavonoids, pectin, citric and malic acids, and a crystallizable fruit sugar and water. Raspberries are high in minerals, especially iron, magnesium, and calcium. Raspberry is well regarded as a women's herb. The leaves are brewed into a tea that is used during pregnancy as well as to increase breast milk after the baby is born. Some women use tea made from raspberry leaves to regulate their menstrual cycles and to decrease heavy menstrual flow. It is also used for gastrointestinal disorders, respiratory illness, the cardiovascular system and for sores in the mouth and throat. The fruit has been found be anticarcinogenic.
Raspberry leaves have been used for centuries by women during pregnancy. But it wasn't until a 1941 study in the British medical journal Lancet that raspberry leaves were scientifically confirmed to contain a complex biochemical that is a uterine relaxant. Raspberry leaves are commonly used throughout pregnancy for many reasons, including helping morning sickness, preventing miscarriage, strengthening the uterus, regulating contractions, and relaxing the uterus during labor. Some pet breeders give a tincture of red raspberry leaves to pregnant cats who are likely to have difficulty in kittening.
Because it is an astringent, raspberry is a gentle antidiarrheal. It is also used to reduce nausea and vomiting, usually for morning sickness.
Mouth and throat sores
Raspberry tea is helpful for healing mouth and throat sores when used as a mouthwash or gargle. It can also be used for bleeding gums and other oral inflammations. Some herbalists recommend it for colds, measles, and coughs.
The fruit of the raspberry may help prevent cancer, according to a January 1999 report in Cancer Weekly Plus. "Ellagic acid in raspberries has been shown in previous studies to be effective in inhibiting cancers in rats and mice," the study detailed. "The compound is…at especially high levels in blackberries and raspberries." Researchers at the Hollings Cancer Center at the Medical University of South Carolina in Charleston gave one cup of raspberries a day to each participant for one year. The study concluded that "… eating red raspberries may possibly prevent cancer by inhibiting the abnormal division of cells and promoting the normal death of healthy cells."
A 2001 study has found that black raspberries appear to be as helpful as red raspberries in preveting or slowing the growth of cancer. Black raspberries, according to an article in the journal Cancer Research, help to protect against esophageal cancer, which is the sixth-leading cause of deaths from cancer worldwide.
Esophageal cancer is one of the deadliest forms of the disease—five-year survival rates range from 8% to 12%. Researchers think that ellagic acid is not the only beneficial compound in raspberries, however, and are presently studying other substances found in the fruit.
Some studies have shown that raspberries may help reduce glucose levels and therefore may be helpful to people with diabetes.
Raspberry leaf tea can be made by adding 1 tsp of the leaf to one cup of boiling water. The leaf should be infused for 10 min and then strained. The infusion can be taken once or twice a day. During pregnancy, use 0.5 oz of leaf to one pt of boiling water and drink once a day. For infant diarrhea, dilute this infusion by 50%. A tincture made of raspbery leaf can be taken three times a day, in 2–4 ml doses.
Wilted raspberry leaves develop a mild poison that may make people ill. When picking the leaves for the tea, the user should make sure that the plant is flowering. Leaves used for steeping to make tea must be fully dried. Another important precaution is to be sure that the raspberries are not contaminated by a gastrointestinal parasite called Cyclospora. The parasite causes a disease called cyclosporiasis, which caused several serious outbreaks in the mid-1990s in the United States and Canada. The Cyclospora parasite was found in raspberries imported from Guatemala.
Although raspberry is used as an antidiarrheal herb, overuse may actually cause diarrhea. In addition, some people may be allergic to raspberries and other berries. Lastly, the tea may sometimes be too tonifying in the early stages of pregnancy; it should be discontinued if contractions increase.
No known adverse interactions with other medications have been reported.
Weiner, Michael. Weiner's Herbal. New York: Quantum Books, 1990.
Ackers, Marta-Louise, and Barbara L. Hervaldt. "An outbreak in 1997 of cyclosporiasis associated with imported raspberries." New England Journal of Medicine (May 29, 1997): 1545-9.
"Black Raspberries Show Multiple Defenses in Thwarting Cancer." Cancer Weekly (November 13, 2001): 24.
Henderson, Charles W. "Red Raspberries May Help Fight Cancer." Cancer Weekly Plus (January 18, 1999).
Katherine Y. Kim
Rebecca J. Frey, PhD