Arginine may lower stroke risk marker

L-arginine has previously been found to lower blood pressure and is often included in nutritional supplements recommended for heart patients.

But a small trial on middle-aged men shows that the amino acid may also benefit the heart through its effect on homocysteine, increasingly considered a marker for heart disease risk.

In a randomized, placebo-controlled, crossover study, researchers from Pennsylvania State University, Kraft Foods and INRA in France tested the effects of a daily 12g dose of L-arginine on 16 middle-age men with hypercholesterolemia.

After each treatment, the team measured blood circulation variables at rest and during two tasks designed to put the heart under stress.

L-arginine had a modest effect on blood pressure – enough to reduce heart disease risk but not enough to allow someone to stop taking blood pressure lowering medication.

However the researchers also found that its presence in the blood was inversely related to a change in plasma homocysteine.

“This study is the first to describe a haemodynamic mechanism for the hypotensive effect of oral L-arginine and the first to show substantial reductions in homocysteine with oral administration,” say the authors in this month’s issue of the Journal of Nutrition (135, pp212-217).