Researchers in one study explained that chronic stress suppresses the immune system, making people more vulnerable to illness. Beta-glucan, doctors believe, helps activate macrophages—the “armed security guard” white blood cells of the immune system that trap and destroy invading bacteria and viruses. In turn, macrophages help launch other immune responses, “T” and “B” cells, that target, kill and produce protective antibodies against future invaders.
In the study, 150 men and women under chronic moderate to high stress, aged 18 to 65, took 250 mg or 500 mg of beta-glucan per day or a placebo. During the four week study, compared to placebo, both beta-glucan groups reported less tension and fatigue, fewer upper respiratory tract infections, and better overall health.