A review and meta-analysis of clinical trials concluded that beta-glucans, found in yeast, grains, mushrooms and other foods, improved fatigue and boosted vigor (energy and vitality), and mood state compared with a placebo.¹ The findings were reported in the August 2025 issue of the Nature publication European Journal of Clinical Nutrition.

“Despite numerous systematic reviews focusing on beta-glucans, none have specifically addressed their effects on fatigue,” Masahiro Muroya and colleagues at the University of Tsukuba in Japan noted.

Among the 10 studies that evaluate the effects of beta-glucans on fatigue, four found significantly lower fatigue scores among participants who received beta-glucans in comparison with a placebo. A third of the nine studies that evaluated vigor found improvements in the beta-glucan-treated groups. And in the 10 studies that assessed beta-glucans’ effects on mood state, seven demonstrated improvements compared with the placebo.

The researchers determined that it may be necessary to consume beta-glucans for at least four weeks to improve fatigue. They noted that there may be benefits for people experiencing physical or mental stress, such as those who engage in regular exercise or have mental health issues.

“The findings from this systematic review and meta-analysis suggest that beta-glucans hold promise as a potential intervention for reducing feelings of fatigue among healthy individuals,” they concluded.

Muroya and associates analyzed data from 12 randomized, placebo-controlled trials that included a total of 1,449 healthy men and women. Beta-glucans used in the trials were derived from reishi and shiitake mushrooms, oats, algae or baker’s yeast. Dosages ranged from 1–2 mg to 1,000 mg and trials lasted 10 days to 16 weeks.