Cranberry is an evergreen shrub whose fruits and leaves have been used in beverages and food. Cranberries has been used traditionally to treat disorders of the bladder, gut, and liver.

There are basically two major species of cranberry:

• Vaccinium macrocarpon – Also known as the American cranberry
• Vaccinium oxycoccos – The European cranberry

What are the chemical constituents of cranberries?

Cranberries are mainly comprised of

• Water (88%)
• Organic acids, fructose, and Vitamin C
• Flavonoids
• Anthocyanidins and proanthocyanidins (part of the natural plant defense system against microbes)
• Iridoid glycosides (responsible for the taste)

Do cranberries benefit urinary tract health?

Cranberry is currently used as a dietary supplement to treat urinary tract infections (UTIs). Supplements are available as capsules, extracts, powders, and tablets.

Several studies suggest that cranberries may decrease UTI frequency who experience recurrent UTIs and after surgery. As per a study published in the American journal of obstetrics and gynecology, the use of cranberry tablets in women undergoing elective benign gynecologic surgery involving urinary catheterization, the rate of UTI was reduced by half during the postoperative period. However, the usefulness of cranberry in those at low-risk for UTI is less clear.

Vaccinium macrocarpon, the American cranberry, is widely utilized to prevent UTIs. Research suggests that proanthocyanidins and polyphenols present in cranberry interfere with adhesion of bacteria, such as Escherichia coli, to epithelial cells of the urinary tract. This retards the development of pathogen reservoirs in the gut and within the urothelium and suppresses the inflammatory response.

Does cranberry protect against cancer?

Phytochemicals present in cranberries have drawn attention from researchers for their potential anticancer activity. Various in vitro and in vivo studies suggest that the anthocyanin, procyanidin, and flavonol components of cranberries may exert anticancer effects.

Phytochemical extracts from American cranberry have been demonstrated to affect human prostate cancer cell growth. The activity was attributed to cell cycle arrest through cell cycle regulation.

In a study of the chemopreventive activity, cranberry-treated mice with human tumor xenografts had reductions in the average size, weight, and volume of tumor xenografts compared with controls.

Does cranberry protect against cardiometabolic disease?

Cranberries have also demonstrated beneficial cardiometabolic effects in several clinical studies. Growing evidence suggest favorable effects of cranberry intake on blood pressure,  cholesterol profile, endothelial function, glucoregulation, inflammation, and oxidative stress. All these contribute to the reduction of cardiometabolic risk factors.

What role do cranberries play in digestive health?

Cranberries, especially the juice of the berries, are known to inhibit the colonization of pathogens such as Helicobacter pylori and Escherichia coli in the stomach; this, in turn, can offer protection against disorders which involve intestinal inflammation. Chemical constituents present in cranberries such as proanthocyanidins, flavonols, and hydroxycinnamic acids inhibit these pathogens by preventing bacterial adhesion, coaggregation and biofilm formation.

Decades of research have helped to elucidate several health benefits of cranberry. From preventing urinary tract infections to modulating gut microbiota, research on cranberry has provided useful insights regarding the benefits on human health. Further studies with well-designed experiments are warranted to better understand the mechanism of action of the chemical constituents.

Further Reading

• All Cranberries Content