Manufacturer study adds evidence supporting more bioavailable form of arginine

Inositol-stabilized arginine is more bioavailable than arginine hydrochloride (HCL), according to new research by sports nutrition ingredient specialist Nutrition 21.

The results, presented at the Nutrition 2018 conference, hosted by the American Society for Nutrition last month in Boston, builds on the manufacturer’s previous studies exploring the bioavailability of inositol-stabilized arginine compared to arginine HCL.

The compound is often used in sports nutrition products to increase blood flow.

The company markets a commercial form of inositol-stabilized arginine, sold under the brand name Nitrosigine. The FDA had no objections for a New Dietary Ingredient notification for Nitrosigine back in 2013, and it achieved self-affirmed GRAS in 2014.

According to the company, the present study further elucidates a potential mechanism which makes Nitrosigine superior to arginine HCL.

“These new findings clearly demonstrate that Nitrosigine and arginine are not metabolized the same way,” said James Komorowski, MS, CNS, chief science officer of Nutrition 21 and a co-author of the study.

“With the discovery that Nitrosigine inhibits the enzyme responsible for the breakdown of arginine, we now better understand why Nitrosigine is significantly better absorbed and more bioavailable than arginine HCL.”

Study details

Ten healthy males were divided into two groups, one supplementing with Nitrosigine and the other with arginine HCL.

The intervention period lasted for 15 days, after which researchers analyzed arginase and ADMA levels—two enzymes known to inhibit arginine levels and nitrous oxide synthesis respectively to increase blood flow.

Participants then refrained from supplementation for seven days (known as a ‘wash-out period’) before crossing over to take the other supplement for another 15 days.

Blood sample analysis suggested that arginase levels were inhibited after participants took Nitrosigine, whereas there were no effects on ADMA levels. Arginine HCL, on the other hand, did not significantly affect either enzyme.

These results add to Nutrition 21’s body of evidence of Nitrosigine’s bioavailability. In 2016, the company presented results from a study that looked at plasma arginine levels after supplementation, in which Nitrosigine significantly increased plasma arginine levels for up to six hours post-dose compared to one hour for arginine HCL.

Source: Nutrition 2018 Conference

Poster presentation, Boston, MA, USA, June 9 – 12, 2018

Arginase inhibition by inositol-stabilized arginine silicate (ASI; Nitrosigine); a novel mechanism by which ASI enhances arginine bioavailability

Authors: Komorowski J, Perez Ojalvo S, Sylla S, Veledar E