Astragalus root extract, a botanical supplement ingredient with a history in traditional medicine as an immune support ingredient, was evidenced in a recent clinical study to modulate immune responses in a way which reduces the impact of maximal-intensity exercise on proper immune function. While moderate exercise is commonly understood to be beneficial to the immune system, research is revealing that strenuous exercise may suppress a healthy immune response by activating immune and endocrine mechanisms due to an inordinate amount of stress. Of the two species typically used in supplements, out of the 2,000 species which exist, the authors of the study used Astragalus membranaceus.
 
In the study, 18 members of the Olympic Polish Rowing Team, all elite athletes with similar diet, exercise programs, and body types, were broken down into a supplement group and a placebo group, and were administered Astragalus Membranaceus Root (AMR) extract at a dose of 500 mg daily throughout the course of a six week intensive training camp. The participants were chosen based on the fact that they were adapted to an elite-level training program, and as a result, had exceptionally high levels of lactic acid.
 
The researchers tested blood samples of the athletes in order to assess concentrations of immune markers, including interleukins 2, 4, and 10, interferon-Y, and lactic acid, as well as subpopulations of three types of immune cells, in order to assess responses to a 2,000 meter maximal intensity test on a rowing ergometer.
 
Following the six-week study duration, AMR supplementation was found to restore a balance in several immunological markers in the athletes, by stabilizing natural killer cells and T-regulatory cells, which was balanced by increases in interferon-Y levels. Additionally, there was a decrease in interleukin 2 levels in reaction to maximal exertion, while interleukin 2/ interleukin 10 levels clearly increased relative to the placebo group.  
 
The authors of the study noted that there was a beneficial immunological response based on the markers of pro- and anti-inflammatory factor levels in the experimental group, which remained in “dynamic balance.”
 
“The discovered immune-tonic effect gives the hope to use AMR in athletes’ daily routine to protect them against Th2-shift related illnesses,” the authors of the study concluded.