Inhaltsstoff-Glossar

Arginine

What Is Arginine?

Arginine is one of the 21 proteinogenic amino acids in the human body. It serves both as a building block for new proteins and as a substrate for important endogenous substances such as nitric oxide (NO). Arginine is a component of both the nitric oxide cycle and the urea cycle, where it contributes to the detoxification of toxic ammonia.

Where Does Arginine Naturally Occur?

Arginine is considered a conditionally essential amino acid, meaning that it must be obtained through the diet only under certain circumstances, such as during growth or illness. Under normal conditions, the body is able to synthesize sufficient amounts to meet its own needs. As a proteinogenic amino acid, arginine is present at concentrations of approximately 5% to 15% in a variety of foods. Many plant-based foods, including peanuts, pumpkin seeds, and peas, are particularly rich sources of arginine.

What Is the Primary Function of Arginine in the Body?

The body requires arginine to produce nitric oxide. During the nitric oxide cycle, arginine is converted into citrulline while one molecule of nitric oxide is released. The nitric oxide produced in this way performs numerous important functions within the body. For example, nitric oxide is involved in regulating neural stem cells and plays a role in biological aging by maintaining endothelial health and stimulating mitochondrial activity. Furthermore, nitric oxide promotes the production of cyclic guanosine monophosphate (cGMP), a signaling molecule that induces relaxation, dilates blood vessels, and is therefore essential for healthy circulation and, among other things, erectile function.

During illness, stress, hypertension, diabetes, and other health conditions, the body increasingly utilizes arginine within the urea cycle. As a consequence, less arginine remains available for the nitric oxide cycle, causing nitric oxide levels in the body to decline. This may lead to complications such as increased inflammatory processes and higher levels of reactive oxygen species. In situations where the body can no longer synthesize sufficient arginine, arginine becomes an essential amino acid that should be obtained through the diet or supplementation.

Benefits

May have positive effects during prolonged stress
May improve vascular function in people with diabetes
May reduce both systolic and diastolic blood pressure in individuals with hypertension

What Are the Benefits of Arginine Supplementation?

Supplementation with arginine can temporarily increase arginine concentrations in the blood serum. Studies have shown that supplementation with up to 9 g of arginine can increase serum concentrations by approximately 70% to 180%. Single doses exceeding 10 g are more likely to cause side effects such as gastrointestinal discomfort and are absorbed less efficiently.

Arginine is considered to have relatively low bioavailability. Oral doses up to 6 g have a bioavailability of approximately 70%, whereas doses of 10 g or more achieve only about 20% bioavailability. Lower doses are therefore considerably more efficient for intestinal absorption. An optimal and very well tolerated single dose is generally considered to be between 3 g and 6 g.

Particularly in individuals suffering from chronic stress or health conditions, arginine supplementation may provide positive effects. Under these circumstances, arginine may shift from being a conditionally essential amino acid to an essential one. People with diabetes who consumed 8 g of arginine daily for 21 days showed improved vascular function and reduced oxidative stress caused by free radicals. During long-term supplementation over 18 months, arginine also increased the likelihood of restoring normal glucose tolerance in people with diabetes.

Arginine supplementation may increase nitric oxide levels and improve blood flow where circulation is impaired. In patients with hypertension, arginine supplementation has been shown to reduce both systolic and diastolic blood pressure.