Combination of Supplements Lowers Blood Pressure

A combination of L-arginine and N-acetylcysteine (NAC) led to impressive reductions in blood pressure and other indicators of heart disease risk in a group of men with type 2 diabetes.

L-arginine, an amino acid (protein building block), is the precursor to nitric oxide, a compound that regulates blood vessel tone and blood pressure. Free radicals can reduce the activity of nitric oxide, so Valentino Martina, MD, of the University of Torino, Italy, and his colleagues decided to also give subjects NAC supplements. They choose NAC because it is a sulfur-containing antioxidant, and sulfur-containing compounds are needed to make nitric oxide.

Martina asked 24 men to take a combination of 1,200 mg L-arginine and 600 mg NAC or placebos daily for six months. All of the men had hypertension, and they stopped taking medications for high-blood pressure 15 days before starting the supplements or placebos.

By the end of the study, men taking L-arginine and NAC had 5-point (mmHg) decreases in both systolic and diastolic blood pressure and significant improvements in endothelial function – that is, blood vessel tone. The men also had numerous other improvements that would likely reduce their risk of coronary heart disease – including decreases in total cholesterol, LDL cholesterol, high-sensitivity C-reactive protein (a marker of inflammation), adhesion molecules (involved in inflammation), and fibrinogen.

“In conclusion,” wrote Martina, “combined NAC and L-arginine administration seems to be a sucessful and well-tolerated antiathergenic therapy...”

Reference: Martina V, Masha A, Gigliardi VR, et al. Long-term N-acetylcysteine and L-arginine administration reduces endothelial activation and systolic blood pressure in hypertensive patients with type 2 diabetes. Diabetes Care, 2008;31:940-944.