The amino acid citrulline is converted to an amino acid called arginine, which is important for promoting blood vessel health and increasing nitric oxide production. The endothelial cells line the inner wall of the blood vessels. They produce nitric oxide from arginine that controls blood flow throughout the body. Poorly functioning endothelial cells make you feel chronically tired, physically unfit, and ruin your sex life.
A Japanese study showed that supplementing the diet with L-citrulline (5.6 grams per day for seven days) reduced blood vessel stiffness in middle-aged men. Citrulline is a healthy food supplement that enhances blood vessel health without side effects. (International Journal Cardiology, published online)