Lingonberries are a fruit that is rich in flavonoid compounds, which have been shown by previous studies to reduce the risks of cardiovascular disease and death.  Flavanols, a sub-group of flavonoids, have been shown to inhibit the development of atherosclerosis in animal models, to improve endothelial function and platelet reactivity, and to reduce blood pressure in humans.  Anne Kivimaki, from the University of Helsinki (Finland), and colleagues compared the effects of long-term dietary treatments with juices made from Finnish berries, cranberry (Vaccinium oxycoccos), lingonberry (Vaccinium vitis-idaea) and blackcurrant (Ribes nigrum) on blood pressure and vascular function, administering the juices for an eight-week period to rats with high blood pressure.  Whereas lingonberry juice improved the functioning of blood vessels, neither cranberry or blackcurrant juices had the same effect.   Reporting that: “Lingonberry juice normalized the impaired endothelium-dependent relaxation of the arteries apparently via [nitric oxide] and [endothelium-derived hyperpolarizing factor], the team concludes that:  “Long-term lingonberry juice treatment improves endothelium-dependent vasodilatation.”