Because of its high tannin content, raspberry leaf tea can be useful for ailments that cause intestinal inflammation and discomfort, such as diarrhea. The tannins reduce swelling by constricting minute blood vessels called capillaries; this prevents oozing or leaking of fluids in the intestines. The herb's astringent quality has inspired other uses as well, including a raspberry leaf tea mouthwash and gargle to soothe canker sores and sore throats.
Some herbalists tout raspberry tea as the ideal beverage to sip throughout pregnancy, because it's helpful for morning sickness and for ''stabilizing'' the uterus, especially in women prone to miscarriage. Indeed, pregnant women throughout the world have drunk raspberry tea without any adverse reactions reported for either themselves or the developing fetus. However, the scientific evidence for raspberry's benefits during pregnancy--or its potential health risks--is scanty and contradictory. The bottom line is that there have been no clinical studies to confirm the effectiveness or safety of raspberry remedies during pregnancy.
When buying raspberry tea in tea bag form, be sure to check the label to confirm that raspberry leaf is the main ingredient. Some teas are simply flavored with raspberry essence and, while they may be pleasant-tasting, such products cannot be expected to provide therapeutic benefit.
