© 2023 MJH Life Sciences™ and Nutritional Outlook. All rights reserved.
A brief look at the new sports market for nitric oxide ingredients
Serious athletes train hard and pay keen attention to how they nourish their bodies. Sports supplements formulated to keep athletes in peak condition generally fall into one of two categories: endurance enhancers or recovery aids. In recent years, the sports nutrition category has flourished with many new ingredients that are backed by scientific studies-much to the delight of the category’s core consumers who have become increasingly wary of products that deliver little more than empty promises.
Of the aforementioned sports dietary supplement ingredient categories, endurance is currently the most rapidly evolving. Sports supplements that enhance endurance typically center on the premise of increasing the body’s natural production of nitric oxide (NO), which increases blood flow (vasodilation), thereby improving the body’s ability to make heightened use of oxygen and nutrients in the muscles. The result is, ideally, an increase in performance potential.
As a precursor to nitric oxide, L-arginine has long been a go-to endurance enhancing ingredient, but there is substantial buzz around a new crop of products capable of producing a similar, if not improved, effect.
Launched in May, Nitrosigine from Nutrition 21 LLC (Purchase, NY) is a patented source of inositol-stabilized arginine silicate with FDA new dietary ingredient (NDI) status. In a preclinical study led by James Russell of the University of Alberta, researchers investigated its metabolic effects and found that it raised blood arginine levels and was “more biologically effective” than arginine hydrochloride.
Pointing to Nitrosigine’s enhancement of coronary blood flow, Russell deems the ingredient a good fit for sports nutrition.
Researchers from Kyowa Hakko USA (New York City), led by Darryn Willoughby of Baylor University, recently discovered that the potential of the amino acid L-citrulline rivals that of L-arginine. The company presented its latest findings earlier this year.
“Our study found 1.6-fold increases in arginine blood levels with L-citrulline administration as compared to L-arginine administration,” said Danielle Citrolo, PharmD, manager of technical services for Kyowa Hakko USA. “This tells us we are able to achieve more effective levels of blood arginine with citrulline than by taking arginine itself. Our data presented was in animals, but this was also demonstrated in humans by Schwedhelm E. et al.”
Kyowa Hakko conducted two human studies-one that focused on blood flow enhancement and one on recovery benefits.
In the first study, researchers confirmed an increase in peripheral blood flow by monitoring the temperature of a hand immersed in cold water. “Supplementation with citrulline enhanced the blood flow in the hand, and it was statistically significant as compared to baseline,” said Citrolo. “Oral citrulline (800mg) showed an effect in raising body surface temperature in the neck, shoulders, and right palm. We believe this is most likely due to increased blood flow due to citrulline-induced vasodilation.”
The second study focused on blood pressure, using the ankle as the point of measurement (the brachial-ankle pulse). Researchers found that after seven days of L-citrulline supplementation there was a statistically significant improvement in the blood pressure, leading to the conclusion that short-term L-citrulline supplementation possibly delivers functional improvement for arterial stiffness.
Vinitrox from Nexira (Rouen, France), anothervasodilation ingredient, is comprised of apple and grape polyphenols. According to Mathieu Dondain, director of marketing and communication, preliminary ex vivo and in vitro studies have confirmed ViNitrox’s specific vasodilating properties.
“The first study conducted by Nexira showed ViNitrox’s dilating effect on the endothelium in isolated rat aortas,” he says, adding that the ex vivo study confirmed increased vasodilation by 50%. “These vasodilating properties have been confirmed and demonstrated by two other studies which show that ViNitrox significantly boosts NO production and induces endothelial NO synthase (eNOS) activation.”
Sidebar: Recovery Roundup
Ingredients that help muscles recover post-training are an important part of increasing athletic performance:
Sidebar: Performance Boosters
Ingredients that deliver performance increase can give athletes a competitive advantage: