Tasting the Seasons: Mushrooms

Mushrooms are surprisingly unique. They are not plants but the fruits of fungi that grow on soil and organic matter like wood, crop residues, and even coffee grounds. Their shapes and forms are countless, and their colours display all the elements of the rainbow.

Mushrooms rise up from organic wastes: yet, they become bountiful and nourishing. (Shu Ting Chang et al. 2017)

⚡️ No time? Save this Quick Card for 5 key insights

Quick Food Science

If we break down mushrooms, we find a complex assembly of hundreds of compounds, including:

Key nutrients

Proteins, with most or all of the essential amino acids – especially oyster mushrooms & white buttons
Dietary fibres that can modulate the gut microbiota and inflammation
Vitamins B, C & D
Essential minerals like selenium, phosphorus, potassium & iron

Bioactive compounds

Polysaccharides, especially ß glucans
Phenolic acids, such as ferulic and caffeic acids
Ergothioneine, a unique amino acid
Carotenoids with structures unique to fungi

So, mushrooms can contribute to our daily requirements for various essential nutrients.

Ergo-what now? These tongue-twister chemicals isolated from mushrooms show health-promoting effects in cell and animal models – such as modulating immune cells, inhibiting cancer cells and reducing oxidation. (Cateni et al. 2022 )

What makes mushrooms special: They provide compounds that are not found in other food sources like ergothioneine and carotenoids with unique structures, offering diversity. For example, ergothioneine is an amino acid with a unique chemical structure and multiple functions in the body, like antioxidant, cytoprotective, and anti-ageing. It’s produced by certain fungi but not by animals or higher plants.

Special mention for Vitamin D

Mushrooms can produce vitamin D when they are exposed to UV light during the growing process. Keep an eye out for mushrooms labelled “UV-treated” or “Rich in vitamin D” at the supermarket.

Q&A Corner

Can you trigger vitamin D production after purchase?

Yes, exposing fresh button mushrooms to midday sun can generate significant amounts of vitamin D2. The amount will depend on the time of day, season, environment, exposure time and type of mushroom.

How does it work? Mushrooms can produce vitamin D2 when exposed to sunlight due to the high concentration of ergosterol in their cell walls. Under UV radiation, ergosterol is transformed into pre-vitamin D2, which then becomes ergocalciferol, or vitamin D2, through a temperature-dependent process.

Slice them up: Slicing mushrooms increases the surface area exposed to sunlight.

Sunbathing your mushrooms

1/ Buy any fresh mushroom you can find, ideally from a local producer.

2/ On a sunny day, slice the fresh mushrooms and place them evenly on a tray exposed directly to midday sunlight for at least 1h

3/ Eat or store in the fridge in a paper punnet

4/ Repeat the next day if you want

Versus supplements: Many variables influence how much vitamin D is produced, including the type of mushroom, time of day, season, latitude, weather conditions, and exposure time. This means that vitamin D generated by mushrooms may not be as reliable as taking a supplement. (Cardwell et al. 2018)

In the human body

What about when we eat them as part of our diet?

Studies on groups of people found that mushrooms in the diet may reduce the risk of chronic diseases, including:

Cancer – 18 grams of mushrooms per day was linked to a 45% lower risk of total cancer, compared to 0 grams, as per a meta-analysis (Ba et al. 2021, Li et al. 2014)
Neurodegenerative diseases – Eating mushrooms regularly was associated with a lower risk of dementia and mild cognitive impairment, as per 2 studies (Zhang et al. 2017, Feng et al. 2019)
Depression – Participants who ate mushrooms had lower odds of having depression, as per a large cross-sectional study (Ba et al. 2021)

How many? These results were found for 18 grams of mushrooms per day. In daily life, it means 126 grams per week or around 2 portions.

Which types of mushrooms? We’re not sure: Human studies usually look at the combined effects of many mushroom types (shiitake, button, field, enoki). The priority is diversity and consistency as part of a balanced diet

Nutrition research is challenging: These results show an association but do not prove causation and come with many limitations. But, combined with lab studies, they suggest that mushrooms deserve a place in our weekly diet.

Back in time: Historical and traditional use

Whole foods like mushrooms are nothing new! People have been using and consuming mushrooms for centuries. There is evidence of their inclusion in the diet of Greeks and Romans, who considered them “the food of the Gods”.

Planetary Health: Growing mushrooms to clean the earth

Mushrooms are also environmental superheroes! Here are 3 ways mushroom cultivation benefits the environment:

1/ By reducing pollutants in the environment

Mushrooms are natural waste decomposers. They break down organic wastes, preventing them from being carelessly disposed of by dumping or burning, which causes pollution.

2/ By helping restore damaged environments

Mushrooms are like forest carers. Their mycelia help filter toxic waste from water in the soil, restore forests, decontaminate the area, and control insect pests.

3/ By replacing some red meat intake, which reduces deforestation & related emissions

If we replace 1/5 of the red meat we eat globally with protein derived from fungi or algae by 2050, we could reduce annual deforestation and related emissions by about 50%, as per a study published in Nature.

So, not only can we enjoy a tasty health-supporting meal but also do our part for the environment, especially if we’re swapping some of our red meat consumption.

Flavour & cooking

The powerful 5th taste: Mushrooms pack a unique, savoury flavour, called umami – also found in meat and fish. They add depth and richness to the overall flavour of a dish.

Interestingly: The umami taste in mushrooms is attributed to a combination of compounds, including glutamate and 5′-nucleotides. (Sun et al. 2020)

Culinary chameleons: They can complement a variety of ingredients, making them versatile in many cuisines, from Italian to Chinese to American. You can grill them, sauté them, or use them in a soup or a stew to add a delicious flavour to your meals.

Ease into them: If you don’t like the texture, start by shredding them into your meals like risotto, omelette, or pasta sauces, or blending them into a broth.

To find out more about different mushroom varieties and connect with mushroom lovers, check out the Mushroom Council.

Q&A Corner

To Wash or Not to Wash? The great debate over washing mushrooms before cooking continues to puzzle many. Different people have different rules. The main concern with washing mushrooms is the excess moisture they can absorb, which can impact their texture and flavour.

Overall: Mushrooms are delicate – take a gentle approach.

1/ Check them out: Give your mushrooms a quick inspection.

2/ Wipe or brush them clean with a dry brush or a damp washcloth to remove any patches of dirt.

3/ The Quick Rinse: If needed, give them a quick rinse under running water.

But if you do, remember to:

Wait until just before cooking
Pat them extra dry with a towel or by transferring them to a salad spinner to get rid of extra moisture

Another thing: When storing, avoid plastic wrap to prevent mushrooms from becoming soggy or moulding prematurely. Instead, opt for a paper bag or cardboard box which prevents condensation.

My favourite ways to eat mushrooms

No-recipe cooking

Cast iron pan – Tear your mushrooms, and add them to a cast iron pan with a little oil. Allow them to cook fast without jiggling them in the pan as this will release water. Instead, they will lightly char and colour. Take off the heat, and sprinkle with salt.
Air fryer – Smother in oil, seasoning, cajun spice blend and fine bread crumbs. Cook for about 12 minutes at 200 for crispy mushrooms.
Oven – Finely chop your mushrooms, and add to a large tray with olive oil and salt. Roast for 20 minutes at 200C. Remove from the oven, stir them, then add paprika, soy sauce and a dash of maple syrup. Stir through and roast for another 15 minutes until deeply coloured.

Mushroom recipes

From the Doctor’s Kitchen app with step-by-step images and nutrition information

Creamy Cashew & Mushroom Pasta

Onion, Mushroom and Miso Soup

Chickpea and Mushroom Curry

Chicken and Mushroom Cacciatore

Mushroom Bourguignon

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