Research Links L-Citrulline and Heart Health

NEW YORKNew data on L-citrulline might help expand its use to include heart health and overall wellness, according to new research from Kyowa Hakko Bio. Taking L-citrulline is 1.6 times more effective at elevating plasma L-arginine levels than taking arginine alone, and findings also associate citrulline supplementation with reduced sensitivity to cold by increasing blood flow to the skin.

The research will be presented by Darryn Willoughby, Ph.D., an International Society of Sports Nutrition (ISSN) Fellow and associate professor of exercise and nutritional biochemistry and molecular physiology at Baylor University. Willoughby will speak at the ISSN Conference and Expo in Colorado Springs on June 14 and 15.

Nitric oxide (NO) is a key molecular and cellular messenger in the body used to increase blood flow through dilation of blood vessels. Arginine, a precursor to NO, has been the standard means of triggering increased production of NO in the body. The new research suggests citrulline may be a more effective way of elevating arginine levels and NO in the body.

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," Willoughby said. Preliminary research with oral L-citrulline has shown elevated plasma L-arginine concentration and augmented NO-dependent signaling."

Findings also indicate a short-term citrulline supplementation could functionally improve atrial stiffness in humans by increasing vascular relaxation and increasing blood flow to the body.

Citrulline may find new applications in the muscle building, fatigue relief and energy markets considering the link between NO production and athletic performance.

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.

Previous research shows L-citrulline-malate supplementation can also enhance the body's use of amino acids during exercise.