Data shows L-citrulline is 1.6 times more effective at elevating plasma L-arginine levels.
A standard way to raise the body’s blood circulation has been to increase nitric oxide production by way of L-arginine supplementation. L-arginine is a precursor to nitric oxide. Nitric oxide is a key molecular and cellular messenger that increases blood flow by dilating blood vessels. Now, researchers from ingredient supplier Kyowa Hakko Bio (New York City) say new rat studies indicate that another amino acid, L-citrulline, may actually help raise plasma L-arginine levels beyond what supplementation with just L-arginine alone can do. The company is presenting its data at next week’s International Society of Sports Nutrition Conference and Expo.
Specifically, the firm says data shows L-citrulline is 1.6 times more effective at elevating plasma L-arginine levels compared to supplementing with arginine alone.
“The importance of L-citrulline for ergogenic support is because L-citrulline is not subject to pre-systemic elimination and could be a more efficient way to elevate extracellular L-arginine levels. Preliminary research with oral L-citrulline has shown elevated plasma L-arginine concentration and augmented NO-dependent signaling,” said Dr. Darryn Willoughby, who will present the research data at the conference. Willoughby is an International Society of Sports Nutrition Fellow and associate professor of exercise and nutritional biochemistry and molecular physiology at Baylor University.
Additionally, the studies showed that L-citrulline supplementation reduced the body’s sensitivity to cold temperature by increasing blood flow to the skin.
The company says all of this new evidence may have applications not only for improving circulation and reducing sensitivity to cold, but also for heart health and sports nutrition due to nitric oxide benefits. “Compared to L-arginine, L-citrulline may be an alternative approach at NO-induced increases in muscle blood flow that may provide an anabolic approach to exercise training,” Willoughby said.