A 'green' diet-based approach to cardiovascular health? Is inorganic nitrate the answer?

Ingestion of fruit and vegetables rich in inorganic nitrate (NO(3)(-)) has emerged as an effective method for acutely elevating vascular nitric oxide (NO) levels through formation of an NO(2)(-) intermediate. As such a number of beneficial effects of NO(3)(-) and NO(2)(-) ingestion have been demonstrated including reductions in blood pressure, measures of arterial stiffness and platelet activity. The pathway for NO generation from such dietary interventions involves the activity of facultative oral microflora that facilitate the reduction of inorganic NO(3)(-), ingested in the diet, to inorganic NO(2)(-). This NO(2)(-) then eventually enters the circulation where, through the activity of one or more of a range of distinct NO(2)(-) reductases, it is chemically reduced to NO. This pathway provides an alternative route for in vivo NO generation that could be utilized for therapeutic benefit in those cardiovascular disease states where reduced bioavailable NO is thought to contribute to pathogenesis. Indeed, the cardiovascular benefits of NO(2)(-) and NO(3)(-) are now starting to be translated in patients in several clinical trials. In this review, we discuss recent evidence supporting the potential utility of delivery of NO(3)(-) or NO(2)(-) for the treatment of cardiovascular diseases.