Acute ingestion of approximately 12.8 mmol of dietary nitrate from beetroot juice in healthy adults is associated with a significant correlation between increased red blood cell S-nitrosothiol concentrations and reductions in systolic, diastolic, and mean arterial blood pressure.

When someone eats beetroot juice, the nitrate in it turns into nitrite in the mouth and gut, then enters the blood and gets taken up by red blood cells. Inside the red blood cells, nitrite reacts with molecules to form S-nitrosothiols, which carry nitric oxide to blood vessel walls. The nitric oxide activates a chemical pathway that makes the smooth muscle in the vessel walls relax, causing the vessels to widen and blood pressure to drop.