Cranberries are among the top foods with proven health benefits, according to Amy Howell, a researcher at Rutgers University.
Cranberries are full of antioxidants, which protects cells from damage by unstable molecules called free radicals.
The National Institutes of Health is funding research on the cranberry's effects on heart disease, yeast infections and other conditions, and other researchers are investigating its potential against cancer, stroke and viral infections.
So far, research has found:
Drinking cranberry juice can block urinary infections by binding to bacteria so they can't adhere to cell walls. While women often drink unsweetened cranberry juice to treat an infection, there's no hard evidence that works.
A compound Howell discovered in cranberries, proanthocyanidine, prevents plaque formation on teeth; mouthwashes containing it are being developed to prevent periodontal disease.
In some people, regular cranberry juice consumption for months can kill the H. pylori bacteria, which can cause stomach cancer and ulcers.
Preliminary research also shows:
Drinking cranberry juice daily may increase levels of HDL, or good cholesterol and reduce levels of LDL, or bad cholesterol.
Cranberries may prevent tumors from growing rapidly or starting in the first place.
Extracts of chemicals in cranberries prevent breast cancer cells from multiplying in a test tube; whether that would work in women is unknown.