Consumption of the humble white button mushroom may boost the immune system and protect again infection, suggests a new animal study from the US.
If the results can be translated to humans, the research could significantly enhance the health profile of the fungi recently reported to contain high concentrations of super-antioxidants.
A study from Pennsylvania State University showed white button mushrooms to be the richest source of ergothioneine. The sought after super-antioxidant is present in mushrooms at 12 times the levels of wheat germ - once thought to be the highest natural source ofergothioneine.
The new study, published in the Journal of Nutrition, suggests that the mushroom may also be able to boost both innate and acquired immune system health.
"This is the first published study showing effect of white button mushrooms on immune function," lead author Dayong Wu from Tufts University told NutraIngredients.com.
The innate immune system refers to the immune system we are born with, and is the body's first line of defence. The acquired immune system comes into action if a pathogen can get past the innate system and tailors the immune response specifically to deal with the invading organism.
The Tufts University researchers, in collaboration with researchers from China's National Institute of Communicable Disease Control and Prevention, looked at the effect of feeding C57BL/6 mice a diet containing white button mushroom powder (0, 2, or 10 per cent) for 10 weeks on both markers of innate and acquired immune system health.
"Little is known about the immunological effect of a dietary intake of white button mushrooms, which represent 90 per cent of mushrooms consumed in the US," wrote the researchers.
Wu and co-workers reported that supplementation with the mushroom boosted the activity of natural killer (NK) cell activity, and production of tumour necrosis factor- (TNF) and interleukin-2 (IL-2).
Natural-killer cells, or NK cells, are a vital part of the immune system. In addition to killing viruses, they have been shown to kill cancer cells in laboratory tests. Depressed NK activity has been associated with increased cancer incidence as well as an increased susceptibility to colds and infections.
On the other hand, no in the production of IL-6, prostaglandin E2, nitric oxide, and H2O2 in macrophages. In addition, no changes in total T cells were observed.
"These results suggest that increased intake of white button mushrooms may promote innate immunity against tumours and viruses through the enhancement of a key component, NK activity," concluded the researchers.
Significant further research is needed, but Wu told this website: "The findings in this study imply that consuming white button mushrooms may have a benefit in promoting the body's anti-microbial and anti-tumour defence. Therefore, our future direction is to test whether this is true in animal models of viral and bacterial infections, and perhaps for tumours as well.
"On the other hand, we could also conduct a human study to verify our findings in animals regarding the effect of white mushrooms on immune cell functions. Considering these mushrooms are already part of our diet and the safety issue should not be much a concern for human study. At this time, however, we don't have a funding yet to conduct these studies."
Statistics from various groups around the EU, US and Australia as well as the FAO have shown a sharp increase in the demand for mushrooms, as modern consumers are increasingly seeking health-added benefits to their foods.
Processed mushrooms account for 55 per cent of the total world market, largely because of the fungi's short life span. Of this 55 per cent, 50 per cent are canned and 5 per cent are dried. The Netherlands has the strongest hold on canned mushroom processing with a 39 per cent share, closely followed by China.
Forty-five per cent of the world's supply is consumed in un-processed form. This market is making moves to pass processed mushrooms as new consumers, lured by health benefits, are drawn to fresh mushrooms. Statistics from Australia and the FAO indicate that this sector will experience the most growth in the coming years.
Source: Journal of Nutrition
June 2007, Volume 137, Pages 1472-1477
"Dietary Supplementation with White Button Mushroom Enhances Natural Killer Cell Activity in C57BL/6 Mice"
Authors: D. Wu, M. Pae, Z. Ren, Z. Guo, D. Smith and S.N. Meydani