With such a wide choice of mushrooms to incorporate into our diets, it can be challenging trying to decide which varieties we should have on our plate (from the more familiar white button mushroom, shiitake, reishi to the lesser known cordyceps, lion’s mane and shaga), what their nutritional benefits are and the effect they have on our bodies.
Mushrooms are a nutritionally dense high-plant protein source whose health benefits far surpass what is known about the common portobello mushroom – which is often little or nothing. They contain essential amino acids and should feature in most vegan and vegetarian diets; and be more prominent in the dining habits of meat eaters.
Mushrooms as medicine?
These mushrooms have been around a long time. China has been using medicinal mushrooms in Traditional Chinese Medicine (TCM) since ancient times for their therapeutic properties: they are antibiotic, anti-parasitic, anti-inflammatory, anti-cancer and anti-viral. Some studies go further to describe mushrooms as anti-obesity and anti-diabetic. Most of the mushrooms are edible, with the exception being reishi – they are too tough to eat but can be consumed (like the others) in a capsule or powdered form.
So, what are the active ingredients in mushrooms?
- Beta glucans – these are naturally occurring long chain polysaccharides, the most studied being (1,3)-beta-glucans which are a source of dietary fibre for our gut. These polysaccharides act as prebiotics in the digestive system, therefore playing a role in improving our gut microbiota. Beta-glucans are known to have healing and immunostimulating properties – by improving the function of both macrophages (which engulf microbes) and natural killer (NK) cells. In addition, they have anti-carcinogenic properties and can inhibit tumour growth (by activating the NK cells and microphages cytotoxicity). Recent studies show that beta-glucans are effective at reducing cholesterol levels.
Polysaccharides also have anti-oxidative characteristics which are usually accompanied by increased activity of the liver oxidative enzymes like superoxide dismutase (SOD), glutathione peroxidase and catalase which are key for detoxification.
- Proteogylcans(aka glycoproteins) – these are polysaccharide-protein complexes which also have immunomodulatory and anti-tumoural properties.
- Triterpenes have an anti-inflammatory effect on our bodies by suppressing tumour necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) which are inflammatory cytokines that affect B-lymphocyte cell function . Increased production of these cytokines is linked to many diseases.
- Sterols – these are a type of fat. Most fungi have ergosterol as their major sterol which has antiviral and anti-tumour properties.
In Part II, the common medicinal mushrooms and their specific actions will be discussed.