Orlando, Florida, Wednesday, March 2, 2004 – The results of a clinical trial investigating the effects of Jarrow Formulas’ L-Arginine (L-arg) were presented by Dr. Shiela West of the University of Pennsylvania at the annual American Heart Association meeting held November 9-12, 2003 in Orlando, FL.

L-Arginine is the precursor for the potent vasodilator nitric oxide, and a growing body of research shows that L-arg lowers blood pressure (BP) and total peripheral vascular resistance (TPR).

Dr. West’s team measured the effects of short-term, oral L-arg supplements (12 g/d for 3 weeks) on systemic hemodynamics in 16 hypercholesterolemic men with normal BP.  In this randomized, double-blind, two-period crossover design, L-arg tablets (1 g each) and matched placebos (microcrystalline cellulose) were provided by Jarrow Formulas. 

Following each supplement period, hemodynamic measures were collected via impedance cardiography during a 30-minute baseline rest period at rest and during 2 behavioral stressor tasks (a brief public speaking task and the foot cold pressor, separated by a 20 min recovery period).  Compared to levels collected during placebo, L-arg significantly reduced systolic BP (- 3.1 mmHg, p<.05) and diastolic BP (-2.2 mmHg, p<.001), and these changes were equally evident at rest and during acute laboratory stressors.  BP reductions were associated with a significant decrease in cardiac output (-0.3 L/min, p<.01), and these changes were mediated by small reductions in stroke volume (-2.6  ml/beat, p = 0.07).  Plasma arginine increased 54% during the supplement period vs. placebo (p<0.0001).  Homocysteine (Hcy) decreased from 14.1 ± 1.1 umol/l during placebo to 12.0 ± 0.2 umol/l with L-arg (p = 0.03), and reductions were largest in subjects with the biggest increases in plasma L-arg (r = -0.49, p = .07).

In conclusion, 12g L-arg supplementation significantly lowered blood pressure and Hcy levels during a three-week period.   “This study is the first to examine systemic hemodynamic effects of oral L-Arginine and the first to report reductions in homocysteine with oral L-Arginine,” said Sid Shastri, Vice President, Product Development at Jarrow Formulas. “Lower homocysteine may be one of many mechanisms, including modulation of endothelial nitric oxide, for the well-documented cardiovascular effects of L-Arginine.”
 For more technical information, contact Sid Shastri, Vice President, Product Development or for all other inquiries Mark Becker, Director, Advertising/Communications toll free at (800) 726-0886 or access the Jarrow Formulas Web site at www.Jarrow.com.

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