In test-tube experiments, scientists compared the cardioprotective effects of cranberry juice to those of apple, cocoa, red wine, and green tea. Their findings revealed that cranberry juice contains compounds known to prevent the constriction of blood vessels and, in turn, protect against high blood pressure.
While it's too soon to tell whether cranberry juice can promote cardiovascular health in humans, previous studies have shown that the antioxidant-rich drink may help prevent urinary tract infections and reduce risk of gum disease.
A number of other natural substances are known to shield heart health. Flaxseed may help keep cholesterol in check, for instance, while vitamin D could help curb inflammation (a key risk factor for heart disease).