Nutrients, Herbs and the Immune System

Healthy Athletes: Probiotics Reduce Illness after Strenuous Exercise

Doctors said that the benefits of probiotics include boosting the immune function, and wanted to test the effects of probiotics in elite athletes. In the study, 20 active professional rugby players took a daily combination of probiotics or a placebo for four weeks, then switched placebo and probiotics for another four weeks. The probiotics combination included several lactobacilli and bifidobacteria varieties.

During the probiotics phases, nearly half of those taking probiotics reported having no respiratory or gut illness symptoms compared to 20 percent of those during the placebo phases. Also during the probiotics phases, those taking probiotics reported 42 percent fewer days of illness compared to the placebo phases.

Reference: Journal of Dietary Supplements; 2013, Vol. 10, No. 3, 171-83

Yeast Beta-Glucan Increased Immunity

After strenuous exercise, the natural immune capacity of mucous membranes that line the air passageways and digestive tract can deteriorate for up to 24 hours, increasing chances for infection.

In the first of two studies, 182 marathon runners took 250 mg of yeast beta-glucan per day, or a placebo, for 28 days immediately after a marathon. Compared to placebo, those who took yeast beta-glucan had 37 percent fewer cold or flu symptoms overall.

In the second study, 60 men and women took a placebo or 250 mg of yeast beta-glucan per day 10 days before attempting a strenuous 50-minute cycling exercise. Two hours after completing the cycling test, compared to placebo, the yeast beta-glucan group had 32 percent higher levels of a salivary antibody, signaling the mucous membranes were stronger, and could resist infection better.