(HealthDay News) — Regular consumption of Lentinula edodes (shiitake) mushrooms is associated with improved human immunity, according to a study published online April 11 in the Journal of the American College of Nutrition.

Xiaoshuang Dai, from the University of Florida in Gainesville, and colleagues examined whether consumption of whole, dried shiitake mushrooms could improve human immune function in a study involving 52 healthy adults aged 21 to 41 years. Participants in the four-week, parallel-group study consumed 5 or 10 g mushrooms daily. Blood was drawn and saliva and serum were collected before and after the study.

The researchers observed increased ex vivo proliferation of γδ-T cells and natural killer T-cells (60 percent and two-fold increase, respectively; both P < 0.0001) with four weeks of mushroom consumption. A greater ability to express activation receptors was seen in both cell types with mushroom consumption. There was an increase in secretory immunoglobulin A in saliva and a reduction in C-reactive protein in serum. There was a significantly different pattern of cytokines secreted before and after mushroom consumption, with increased interleukin (IL)-4, IL-10, tumor necrosis factor α, and IL-1α levels, and decreased macrophage inflammatory protein-1α/chemokine C-C ligand 3 levels with consumption.

“Regular L. edodes consumption resulted in improved immunity, as seen by improved cell proliferation and activation and increased sIgA production,” the authors write.

Funding was provided by the U.S. Mushroom Council and the Australian Mushroom Growers Association.

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