Mushrooms are widely acknowledged to contain numerous bioactive compounds that have positive health effects on the body, including immunomodulating, anti-tumour, hypocholesterol and anti-bacterial properties, as well as cardiovascular health benefits.
This bioactive potential and the wide interest in the ‘traditional’ health aspects of the fungus has led to recognition of the term ‘mushroom nutraceuticals,’ explained the research team; a collaboration which included the University of Porto and the Polytechnic Institute of Bragança, Portugal.
“A mushroom nutraceutical is considered a refined or partially refined extract or dried biomass from either mycelium or the fruiting body of a mushroom which is consumed in the form of pharmaceutical formulations, capsules or tablets, as a dietary supplement and has potential therapeutic applications,” wrote first author Filipa Reis.
“Mushrooms are natural matrices of excellence. Their bioactivity has been proved and therefore, their incorporation in foods has been studied.
"However, these new food products have not yet gone to market and most of the mushrooms and their compounds are mainly consumed in their natural form or in dietary supplements,” concluded the researchers.
“Despite interest in such products having grown over the years, in Western countries, mushroom products are not as common as in Asia and legislation needs to be implemented to permit an increase in their consumption,” they added.
Source of natural health-promoting properties
Although most studies on antioxidant properties of mushrooms have been in vitro assays, some in vivo evidence also exists.
One study reported that Agaricus bisporus (champignon) improved liver and heart function in mice, while Pleurotus species was shown to positively influence enzymes involved in the antioxidant defence system in rats.
Other studies have shown that mushrooms exhibit antibacterial, antifungal, antiviral and anti-parasitic properties.
In particular, the widely consumed champignon mushroom has displayed efficacy against gram-positive bacteria – despite a lack of understanding of the mechanism of action involved.
Influencing immunity
Mushrooms can influence immunity through the activation of components from the innate immune system such as natural killer cells, lymphocytes, neutrophils or macrophages. They also have potential chemoprotective properties.
“Numerous studies have confirmed the anti-tumour potential of extracts and compounds obtained from different mushroom species,” wrote the researchers.
“Moreover, many other studies have been undertaken to identify mushroom extracts/fractions/compounds with anti-tumour potential and further develop nutraceuticals and/or pharmaceutical formulations”.
Uses in functional foods
From a commercial point of view, the benefits of mushrooms could lead to the possibility of new functional foods with new flavours.
Mushrooms could be used as a replacement for cereal flours as they are a rich source of dietary fibre, and as bread flour with a high umami intensity. The bread would also benefit from high amounts of the amino acids γ–aminobutyric acid and ergothioneine
Functional cheeses and cheese-related products could also be on the horizon with the help of mushrooms.
One study used mushroom extracts to create a functional cheese-like food which had suggested preventive effects against cancer and thrombosis.
The authors concluded their review by saying there is “enormous potential” of using mushrooms in functional foods.
Safety
Edible mushrooms have generally been shown to have low or zero toxicity, the researchers explained. Nevertheless, some side effects including bloating and/or diarrhoea have been observed from shiitake mushroom consumption.
These issues should addressed in further studies to fully exploit the benefits of mushrooms in functional foods, recommend the researchers.
Source: Trends in Food Science & Technology
Published online, DOI: 10.1016/j.tifs.2017.05.010
“Functional foods based on extracts or compounds derived from mushrooms”
Authors: Filipa S. Reis, Anabela Martins, M. Helena Vasconcelos, Patricia Morales and Isabel C.F.R. Ferreira