From the Guidelines
Arginine supplements can cause a decrease in blood pressure, as evidenced by a study published by Nagaya et al, which found a 9% decrease in mean pulmonary arterial pressure and a modest decrease in mean systemic arterial pressure with oral L-arginine supplementation 1.
Key Findings
- The study found that oral supplementation of L-arginine (0.5 g/10 kg body weight) significantly increased plasma L-citrulline, indicating enhancement of NO production 1.
- Supplemental L-arginine produced a 9% decrease in mean pulmonary arterial pressure (mPAP) and a 16% decrease in pulmonary vascular resistance (PVR) 1.
- L-arginine modestly decreased mean systemic arterial pressure (92 ± 4 to 87 ± 3 mm Hg, p < 0.05) 1.
Mechanism of Action
- Arginine works by potentially increasing nitric oxide production in the body, which helps blood vessels relax and dilate, improving blood flow and potentially lowering blood pressure 1.
Important Considerations
- The effect of arginine supplements on blood pressure may not be consistent across all populations, and more research is needed to fully understand its effects 1.
- Potential drawbacks of arginine supplementation may include an increase in the concentration of polyamines, which are proproliferative 1.
- Arginine supplements may interact with certain medications, including blood pressure medications, erectile dysfunction drugs, and blood thinners, so consulting with a healthcare provider before starting supplementation is important.
From the Research
Arginine Supplementation and Blood Pressure
- The effect of arginine supplementation on blood pressure has been studied in several trials, with most showing a decrease in blood pressure 2, 3, 4, 5.
- A meta-analysis of 11 randomized, double-blind, placebo-controlled trials found that oral L-arginine supplementation significantly lowered systolic blood pressure by 5.39 mmHg and diastolic blood pressure by 2.66 mmHg 2.
- Another study found that L-arginine supplementation lowered blood pressure by 5.39/2.66 mmHg, which is comparable to the effects of diet changes and exercise implementation 3.
- A single-blind, controlled, crossover dietary intervention study found that L-arginine-rich diets decreased blood pressure in healthy volunteers, with a decrease in systolic blood pressure of 6.2 mmHg and diastolic blood pressure of 5.0-6.8 mmHg 4.
- An umbrella review of meta-analyses found that L-arginine supplementation reduced systolic and diastolic blood pressure in hypertensive adults by 2.2-5.4 mmHg and 2.7-3.1 mmHg, respectively 5.
Mechanism of Action
- The mechanism by which arginine supplementation lowers blood pressure is thought to be related to its role as a substrate for nitric oxide synthase, which produces nitric oxide, a vasodilator 6, 3.
- The "L-arginine paradox" refers to the phenomenon where elevated plasma arginine concentrations increase endogenous nitric oxide production, despite normal plasma arginine concentrations exceeding the Michaelis constant of nitric oxide synthase 3.