Cranberries are delicious, whether dried and sweetened or served in cranberry sauce, cranberry juice cocktail or cranberry muffins. But there are other reasons to love cranberries. Current scientific research reveals that the tart red berries are among the most healthful of all berries, and that they have more antioxidant activity than almost any other fruit. As the frequency of cancer, heart disease and other chronic conditions rises throughout the world, researchers are increasingly focusing on cranberries to find new ways to promote good health and prevent disease.
Would you be surprised to learn that the tradition of serving cranberry sauce for Thanksgiving is as old as the holiday itself? Cranberries are indigenous to North America and have grown abundantly in the wild for centuries. Native Americans along the East Coast enjoyed wild cranberries cooked with maple syrup or honey, and they most likely shared this treat with colonists at early Thanksgiving feasts.
Native Americans had other uses for cranberries as well, such as using the berries to make dyes and clean wounds.
In 1816, Henry Hall began cultivating cranberries in Dennis, Massachusetts, and by the 1820s American farmers were exporting cranberries to Europe. In 1840, Hall observed that the berries flourished when sand was fortuitously swept into his bog by strong winds, stifling the growth of shallow weeds and supporting healthy growth of the deep-rooted cranberry bushes. This discovery allowed cranberry production to increase greatly; today, the United States produces 154,000 tons of cranberries each year, the majority of which come from Wisconsin and Massachusetts.
Cranberries and Urinary Tract Health
Studies suggests that cranberries and cranberry juice may help maintain a healthy urinary tract by preventing the occurrence of urinary tract infections (UTIs). Scientists once believed that a chemical constituent of cranberries called hippuric acid was responsible for preventing UTIs. Early cranberry studies proposed that hippuric acid helped to acidify urine enough to prevent harmful bacteria from causing an infection. However, subsequent studies have failed to prove this theory or demonstrate that hippuric acid in the urinary tract reaches levels sufficient to inhibit bacterial growth.
More recent research suggests a different reason for cranberry’s urinary health benefits – cranberry may prevent harmful bacteria from adhering to the urinary tract altogether. A 1998 study suggests that compounds called proanthocyanidins, which are found in cranberries, function similarly to the body’s Tamm-Horsfall glycoprotein, which keeps bacteria from adhering to bladder cells.
UTIs are caused by a class of bacteria that includes the E. coli, Proteus and Pseudomonas species. The fimbriae (fringes) that surround these bacteria allow the bacteria to attach to the epithelial cells of the urinary tract and create an infection. However, in an in vitro study published in 1988, researchers showed that bacterial fimbriae are less likely to stick to the urinary tract after cranberry juice consumption. These results suggest that cranberry is more effective at preventing infections than curing them.
In 1994, researchers conducted a large double-blind, placebo-controlled trial that stands out as one of the most important human trials on cranberry and urinary tract health. The researchers gave 153 elderly women 300 milliliters (10 ounces) of cranberry juice per day for six months and noted the subsequent occurrence of UTIs. The juice-drinking participants experienced fewer UTIs than participants in placebo group. Additionally, only 15 percent of the juice group had bacteria in their urine, compared to 28 percent of the placebo group.
Cranberry may have other positive effects on the urinary tract. A few preliminary uncontrolled studies have shown that cranberry juice may help reduce the odor or urine and the occasional burning sensation that accompanies urination. Further research is needed to confirm these benefits.