Mushroom polysaccharide extracts show promise for helping counter the depression in immune function that accompanies strenuous prolonged exertion and heavy training1. Polysaccharides from Ganoderma lucidum prevented exercised-induced suppression of haematopoetic parameters in mice and 100mg/day of a purified beta-glucan preparation from Pleurotus ostreatus maintained natural killer cell activity and reduced the frequency of upper respiratory tract infections (URTI) in elite athletes2-4.
The ability of mushrooms to help prevent URTI is due to their common immune-modulating action and is not specific to any one species (1-3g/day).
1. Exercise and the immune response. Keast D, Cameron K, Morton AR. Sports Med. 1988 Apr;5(4):248-67.
2. Immunomodulatory effect of Ganoderma lucidum polysaccharides (GLP) on long-term heavy-load exercising mice. Shi Y, Cai D, Wang X, Liu X. Int J Vitam Nutr Res. 2012 Dec;82(6):383-90.
3. Effect of Pleuran (β-glucan from Pleurotus ostreatus) supplementation on cellular immune response after intensive exercise in elite athletes. Bobovčák M, Kuniaková R, Gabriž J, Majtán J. Appl Physiol Nutr Metab. 2010 Dec;35(6):755-62.
4. Pleuran (β-glucan from Pleurotus ostreatus) supplementation, cellular immune response and respiratory tract infections in athletes. Bergendiova K, Tibenska E, Majtan J. Eur J Appl Physiol. 2011 Sep;111(9):2033-40.