A new study suggests a combination of Setria glutathione and L-citrulline may be effective at increasing nitric oxide levels after exercise.
Nitric oxide (NO) plays a key role in supporting blood flow and oxygen delivery to muscles after intense exercise, and a new study suggests a combination of Setria Glutathione and L-citrulline may be effective at increasing NO levels in young men after resistance exercise sessions.
The double-blind study, led by Darryn Willoughby, PhD, and published in the Journal of the International Society of Sports Nutrition, investigated the effects of Setria Glutathione and L-citrulline on 60 healthy, resistance-trained males aged 18-30. Setria Glutathione is manufactured by Kyowa Hakko USA Inc. (New York City).
The men were randomly divided into four groups and received either a placebo, 1 gram Setria Glutathione, 2 grams L-citrulline, or a combination of 200mg Setria Glutathione and 2 grams L-citrulline to take daily for one week. At the end of the 7-day period, the men performed resistance exercise sessions involving the elbow flexors and their blood was collected to assess NO levels.
The researchers found that the combination of Setria Glutathione and L-citrulline did in fact increase NO levels in the blood to a significantly greater degree than the placebo. What’s more, at 30 minutes after the exercise, the Setria Glutathione/L-citrulline group was the only group to present such a striking improvement over the control group.
“In the present study, significantly different increases in NOx occurred 30 min following resistance exercise, and only for the L-citrulline and [Setria Glutathione] group,” wrote the study’s authors. The combination also increased levels of plasma cGMP, but not significantly.
The same paper also included an in vitro and rodent study of the effects of the Setria Glutathione and L-citrulline combination, which also found that the combo “has the same positive, long lasting benefit of enhancing nitric oxide across a variety of subjects, as well as blood levels of NOx,” according to a press release.
“In this study, we were able to determine that combining Setria Glutathione with L-citrulline not only increased blood levels of nitrite and NOx, but sustained the increases for a longer period of time, compared to placebo,” said Willoughby. “The results of this first-of-its kind study indicate that Setria Glutathione and L-citrulline may play a role in muscle protein synthesis and muscle performance when combined with resistance exercise.”
McKinley-Barnard S et al. “Combined L-citrulline and glutathione supplementation increases the concentration of markers indicative of nitric oxide synthesis.” Journal of the International Society of Sports Nutrition. Published online June 10, 2015.
Nutritional Outlook Magazine
Photo © iStockphoto.com/spanteldotru