The Cardioprotective Role of Nitrate-Rich Vegetables

Abstract

Nitric oxide (NO) is an inorganic radical produced by both the non-enzymatic nitrate (NO₃^-)-nitrite (NO₂^-)-NO pathway and enzymatic reactions catalyzed by nitric oxide synthase (NOS). Also, as nitrate and nitrite from dietary and other endogenous sources can be reduced back to nitric oxide in vivo, the endogenous NO level can be increased through the consumption of nitrate-rich vegetables. Ingestion of dietary NO₃^- has beneficial effects which have been attributed to a subsequent increase in NO: a signaling molecule that may regulate various systems, including the cardiovascular system. A diet rich in NO₃^- from green leafy and root vegetables has cardioprotective effects, with beetroot products being particularly good sources of NO₃^-. For example, various studies have demonstrated a significant increase in nitrite levels (regarded as markers of NO) in plasma after the intake of beetroot juice. The present review describes the current literature concerning the role of nitrate-rich vegetables (especially beetroot products) in the prophylaxis and treatment of cardiovascular diseases (CVDs). This review is based on studies identified in electronic databases, including PubMed, ScienceDirect, Web of Knowledge, Sci Finder, Web of Science, and SCOPUS.

Keywords: beetroot; cardiovascular disease; nitrate; nitric oxide; vegetable.

Figure 1

The nitrate (NO₃⁻)/nitrite (NO₂⁻)/nitric oxide (NO) pathways and beneficial action of nitric oxide in cardiovascular system. Concentrations market for NO₃⁻, NO₂⁻ and NO are those detected (NO₃⁻ and NO₂⁻) or estimated (NO) in blood ([7], modified).

Figure 2

Nitrate content in selected vegetables and their cardioprotective potential. (+) cardioprotective potential; (?) no data about cardioprotective properties.

Figure 3

The therapeutic potential of beetroot products for CVDs and their main biological properties.