For individuals managing Irritable Bowel Syndrome (IBS), the low FODMAP diet is often a recommended strategy to alleviate symptoms. However, navigating this diet can be complex, especially when it comes to commonly consumed foods like mushrooms. Many people assume that all mushrooms are off-limits due to their high FODMAP content. Fortunately, this isn't the case. This article delves into the world of mushrooms, exploring which varieties are low in FODMAPs and how they can be incorporated into a low FODMAP diet.
Understanding FODMAPs
FODMAP is an acronym that stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols. These are short-chain carbohydrates that are poorly absorbed in the small intestine. When these carbohydrates reach the large intestine, they are fermented by gut bacteria, which can lead to symptoms like gas, bloating, abdominal pain, and altered bowel habits in people with IBS. The low FODMAP diet, developed by researchers at Monash University, aims to reduce these symptoms by limiting the intake of high FODMAP foods. It has been shown to reduce symptoms of Irritable Bowel Syndrome in up to 86 % of people with IBS and is designed as a second line diet for IBS after trying to improve symptoms with traditional dietary advice for IBS.
FODMAPs in Common Food Groups
FODMAPs are found in a wide variety of foods, making it challenging to identify which ones to avoid. Key food groups and their common FODMAPs include:
- Fruit: Primarily sorbitol and excess fructose. Examples of fruits high in excess fructose are apples, pears, mangoes, cherries, figs, nashi pears, pears, watermelon and dried fruit. Fruits particularly rich in sorbitol include apples, cherries, nashi pears, peaches and plums.
- Vegetables: Mainly fructans and mannitol. Vegetables particularly rich in fructans include artichoke, garlic, leek, onion and spring onion. Vegetables particularly rich in mannitol include mushrooms and celery.
- Grains and Cereals: Primarily fructans and, to a lesser extent, GOS (galacto-oligosaccharides). Grain and cereal foods particularly rich in fructans include wholemeal bread, rye bread, muesli containing wheat, wheat pasta and rye crispbread.
- Legumes and Pulses: Primarily GOS. Legumes and pulses particularly high in GOS include red kidney beans, split peas, falafels and baked beans.
- Dairy Foods and Alternatives: Mainly lactose. Dairy foods that are high in lactose include soft cheeses, milk and yoghurt.
- Nuts and Seeds: The main FODMAPs present in nuts are GOS and fructans.
It's important to consult resources like the Monash University FODMAP Diet App for the most accurate and up-to-date information on the FODMAP content of specific foods. This app uses a traffic light system to rate foods as low, moderate, or high in FODMAPs.
Why are Mushrooms High FODMAP?
Most mushroom varieties contain mannitol, which is a sugar alcohol. Lion’s mane contains both fructans and mannitol. Black chanterelle, dried, is the only variety that I found that contains the other sugar alcohol, sorbitol.
Read also: Weight Loss: The Mushroom Connection
Low FODMAP Mushrooms
Fortunately, not all mushrooms are high in FODMAPs. Here are some varieties that can be enjoyed in moderation on a low FODMAP diet:
Oyster Mushrooms
Oyster mushrooms are low FODMAP in any amounts, making them a great staple in your diet if you’re following a low FODMAP diet or if you already know you are sensitive to mannitol and need to avoid other mushrooms. They have a mild, delicate flavour that is often described as slightly sweet with a hint of anise. Their taste is subtle compared to more robust varieties like shiitake or portobello. The texture is tender and velvety, becoming slightly chewy when cooked. The texture can vary depending on the variety, with some being more meaty than others. Oyster mushrooms are great as a meat substitute in plant-based recipes due to this texture. However, they are low in protein so this would need to be provided from an alternative source. They can be stir-fried, grilled and made into soups and stews, amongst other uses. It is actually quite easy to grow your own at home. Explore the links below for oyster mushroom growing kits: Thompson-Morgan, GroCycle
Canned Champignon (White Button) Mushrooms
White button mushrooms when fresh are high in the FODMAPs mannitol and fructans, however canned mushrooms are suitable on the low FODMAP diet. But why are canned mushrooms low FODMAP? Well, when they are canned, the water soluble FODMAPs leach out into the water. This makes drained canned button mushrooms low FODMAP mushrooms in a generous serving size of up to 250 g. Canned white button mushrooms have a mild, slightly salty flavour due to the brine in which they are packed. The taste is less earthy and more neutral compared to fresh mushrooms, as some of the natural flavours are diluted in the canning process. The texture of canned white button mushrooms is softer and more uniform compared to fresh mushrooms. They are tender and can sometimes be slightly rubbery, depending on the canning process and storage time. Canned button mushrooms, as well as being low FODMAP mushrooms, are convenient and versatile so can be used in quick and easy recipes. Some ideas include use in soups and stews, pasta or rice dishes, in salads, stir-fries and casseroles and in sauces and gravies.
Shimeji Mushrooms
Fresh shimeji mushrooms are suitable on a low FODMAP diet in amounts of up to 750 g as they have been found to contain no FODMAPs. They are more of a speciality mushroom and it may be tricky to find them. Shimeji mushrooms have a slightly nutty, umami-rich flavour with a hint of bitterness and a firm and crunchy texture when raw. Cooking them removes the bitterness and a savoury, buttery taste develops, making them a flavourful addition to various dishes. On cooking they maintain their shape and firmness, adding a pleasant bite to dishes. They are versatile and can be used in many dishes, including stir-fries, soups, stews and rice dishes and can be added to salads or used as a garnish due to their attractive appearance.
Mushrooms with a Moderate FODMAP Serving Size
Dried Porcini Mushrooms
Porcini mushrooms, also known as penny bun mushrooms, when dried are high in mannitol in large amounts. However, a moderate serving size is 15 g, which is 2 tbsp. This amount is low enough in FODMAPs to be suitable for use in a dish, as long as you avoid any other moderate FODMAP foods in the same meal. Dried porcini mushrooms have a rich, deep, and earthy flavour with some nuttiness and a hint of smokiness. Their umami intensity is increased compared to the fresh mushroom, making them a powerful flavour enhancer in various dishes. When rehydrated, dried porcini mushrooms become tender but retain a slight chewiness. The rehydration process also helps release their concentrated flavours into the soaking liquid, which can be used as a flavourful low FODMAP mushroom broth. They can be added to many meals to add their unique flavour, including soups, stews, risotto, sauces, gravies and in many vegetarian or vegan recipes.
Read also: Are Mushrooms Keto?
Slippery Jack Mushrooms
Slippery Jack, or sticky bun, mushrooms have a decent moderate FODMAP serving size of 61 g, about ¾ of a cup. In larger amounts they are high in the FODMAP mannitol. Again, you would need to ensure you avoid other moderate FODMAP portions of foods in the same meal to avoid potential IBS symptoms. Slippery Jack mushrooms have a mild, slightly nutty flavour with a subtle earthiness. Their taste is relatively delicate compared to more robust mushrooms, making them versatile for various culinary applications. When fresh, Slippery Jacks have a slippery, sticky cap surface, which gives them their name. The flesh is firm and spongy. After cooking, they become tender with a slightly chewy texture. The sliminess of the cap disappears, making them more palatable. Slipper Jacks are used in many European and Russian recipes and are suitable in a variety of dishes. They can be fried, used in soups and stews, pickled, used in stuffings and sauces and in rice dishes.
High FODMAP Mushrooms
Several popular mushroom varieties are high in FODMAPs and should be limited or avoided during the elimination phase of the low FODMAP diet:
Button Mushrooms (Champignons)
Fresh button mushrooms are the most commonly eaten mushrooms in the world. Unfortunately, they are also high FODMAP mushrooms in their fresh form. They contain large amounts of mannitol and are the only mushroom so far tested to contain fructans. This means that they would need to be tested separately to see if you are able to tolerate them, even if your mannitol challenge has been successful in showing no symptoms. White button mushrooms have a mild, earthy flavour that becomes more pronounced and savoury when cooked. Their taste is often described as slightly nutty and subtle, making them versatile for a variety of cooking method. They retain a slightly chewy texture when sautéed or grilled. They are great to use in stir-fries with rice or quinoa, in casseroles and in soups.
Shiitake Mushrooms
Unfortunately fresh shiitake mushrooms are high in FODMAPs as they contain large amounts of mannitol. They have a moderate serving size but it is too small, at 17 g (or just over half a mushroom), to be worth using. Shiitake mushrooms have a rich, savoury flavour with strong umami notes. Their texture is firm and slightly spongy. When cooked they become tender and maintain some chewiness. They are used in a wide variety of dishes, especially in Asian cooking. Dried shiitake mushrooms are also high FODMAP mushrooms, with large amounts of mannitol. They have a low FODMAP serving size of 7 g, however this only equates to about 2 dried mushrooms, which makes them unsuitable during the low FODMAP diet. Shiitake mushrooms are a valued ingredient for their intense flavour and versatility, enhancing a wide range of dishes with their rich umami profile. They are a staple in many cuisines and are particularly prized in Asian cooking for their ability to elevate the taste of many dishes.
Enoki Mushrooms
Fresh enoki mushrooms are high in mannitol. They have a moderate serving size of 12 g, or 3 medium sized mushrooms, otherwise are considered high FODMAP mushrooms. Enoki mushrooms have thin, long stems and small, white caps that give them a distinctive appearance. They are prized for their unique texture and mild flavour, making them a versatile ingredient in a wide range of culinary applications. They are especially popular in Japanese, Korean and Chinese cuisines, where they are used to enhance soups, stir-fries, and salads.
Read also: The Power of Mushrooms
Dried Black Chanterelle Mushrooms
Chanterelle mushrooms, or black trumpets, when dried, are unique in that they are high in the polyol sorbitol, whereas most mushrooms are high in mannitol. These may be a suitable option for you if you discover a sensitivity to mannitol, but not sorbitol. Dried black chanterelle mushrooms are a highly prized ingredient in gourmet cooking, valued for their intense flavour and versatility. Chanterelles have a rich, earthy flavour with subtle smoky and fruity undertones. Their taste is more intense when dried, adding depth to various dishes. They need to be soaked before using in dishes but have a wide range of uses, including adding a meaty texture and umami flavour to many recipes, such as soups, stews, risotto, stuffings and sauces.
Portobello Mushrooms
Fresh portobello mushrooms, also known as portabella or giant cremini mushrooms, are high in mannitol and are unsuitable on the low FODMAP diet in amounts over 15 g. With one portobello mushroom weighing about 85 g, it really isn’t worth using them while you’re following a low FODMAP diet. They are widely used in vegetarian and vegan dishes as a meat substitute for their meaty texture and their size means they are perfect as a burger substitute. They have a rich, earthy flavour with pronounced umami notes. Even after cooking they retain their texture and become tender and juicy. They are good for grilling and stuffing due to their large size, but can also be chopped up and used in a variety of ways.
Red Pine Mushrooms
Red pine mushrooms, also known as saffron milk caps, are high in mannitol in amounts over 27 g. This makes them high FODMAP mushrooms at a reasonable serving size. They have a distinctive, robust flavour. They offer a slightly nutty and earthy taste with hints of fruity and spicy notes. Their flavour is rich, savoury, and can have a slightly resinous quality. When cooked, they become tender but retain a firm and crunchy texture, which makes them suitable for various cooking methods. They are particularly used in Mediterranean and Eastern European cuisines.
Swiss Brown Mushrooms
Swiss brown mushrooms are another high mannitol mushrooms, therefore unsuitable on the low FODMAP diet in any amount. Also known as cremini or baby bella mushrooms, Swiss brown mushrooms have a slightly deeper and earthier flavour compared to white button mushrooms. Their taste is mild, with a subtle nuttiness and rich, savoury undertones. They are versatile and can be used in a variety of dishes from simple sautés to elaborate casseroles as their firm texture holds up well with various cooking methods.
Medicinal Mushrooms and FODMAPs
Lion’s Mane Mushrooms
Lion’s mane mushrooms (Hericium erinaceus) are edible mushrooms found mainly in East Asia. They have been widely used as a food and herbal medicine in traditional Chinese medicine. They are known for their strong bioactive properties and have potential to be used as a neuroprotective agent. Supplement use based on medicinal mushrooms is still in very early stages of development and further research is needed to evaluate the effects and safety of its use. Some studies investigating Lion’s mane mushrooms have shown improvement in mood and cognitive function with daily supplemental use. It is the only mushroom to so far show beneficial effects, which were only see in middle-aged and older adults. Lion’s mane powder is low FODMAP in the serving size of 2 g, which is around the standard size of supplements available. It contains both mannitol and fructan, so care would need to be taken over the use in case of sensitivity to either FODMAP. Studies investigating the effects of Lion’s Mane have typically used up to a maximum of 10 g per day. Even this amount is significantly lower than the moderate FODMAP serving size of 115 g.
Reintroducing Mushrooms
Once you undertake reintroduction, if you tolerate mannitol you will likely be able to reintroduce most of these mushrooms back into your diet. During the elimination phase of the diet, you’ll only be able to include oyster mushrooms. Once you move into the challenge (or reintroduction phase), you’ll be able to test different mushrooms. The mannitol challenge let’s you test button mushrooms in very small amounts, so if you pass that then you know you’ll be able to tolerate other varieties like shitake, portobello and porcini.
The Health Benefits of Mushrooms
Mushrooms offer a unique nutrient profile that supports a variety of health benefits and contributes to improved diet quality. They are rich in essential nutrients, such as B vitamins, selenium, potassium and fibre, addressing some common dietary deficiencies. Mushrooms contain ergosterol, which converts to vitamin D2 upon exposure to UV light, enhancing their nutritional value. This could be especially beneficial for those with limited sun exposure or are otherwise at risk of vitamin D deficiency. Research has indicated potential health benefits such as immune support, anticancer properties and improved metabolic health. They contain bioactive compounds with antioxidant and anti-inflammatory actions. For example, ergothioneine, another unique compound found in mushrooms, acts as a potent antioxidant. More recently, mushrooms have been highlighted for their anti-aging properties. Some studies of limited quality have found that diets including mushrooms, categorised as ‘healthy plant-based’ improve cognitive function, mood and sleep and reduce the risk of all-cause death, dementia and depressive symptoms in diverse populations. However, it is unclear if the effect is due to the plant-based diet or the use of mushrooms themselves. For individuals following plant-based diets, mushrooms serve as an excellent meat substitute due to their umami flavour and meaty texture. Their sustainable production further enhances their appeal as a nutritious and environmentally friendly food choice. making mushrooms a valuable component of a balanced diet.
Canned Foods and FODMAPs
If you’re following a low FODMAP diet for IBS, you might be surprised to learn that some canned foods-like champignon (button) mushrooms-can actually be low FODMAP. This can be confusing, especially since fresh button mushrooms are high in FODMAPs. The key difference lies in how the food is processed. FODMAPs are water-soluble carbohydrates. When high FODMAP foods are canned in water or brine, some of the FODMAPs can leach out of the food and into the liquid (1). This process can reduce the overall FODMAP content of the food. However, the amount of leaching can vary, so it’s not always possible to predict whether a canned product is low FODMAP without lab testing (2). Boiled lentils can contain moderate to high amounts of FODMAPs depending on the serving size, however, canned lentils are slightly lower in FODMAPs and can be enjoyed in ¼ cup serving sizes (1). In canned lentils some of the water-soluble GOS (oligosaccharides) and fructans leach out of the lentils into the water content lowering the FODMAP content (1). Dried chickpeas are considered high FODMAP, however, their canned counterparts are lower in FODMAPs. Again the GOS in the chickpeas leaches out into the water in the can and lowers the chickpea FODMAP level. On the first phase of the low FODMAP diet you can enjoy a ¼ cup serving of canned chickpeas (1). Some canned beans like butter beans, cannellini beans, black beans and red kidney beans also have small low FODMAP serving sizes that can be enjoyed (check the Monash University FODMAP Diet App for more information). While other canned beans like baked beans, borlotti beans, and four bean mix are still high FODMAP despite being canned. Monash University has yet to test a wide range of canned fruit. We do know that canned guava, apricots, pears and peaches are generally considered high FODMAP, although they do have some small low FODMAP serving sizes (check the Monash University FODMAP Diet App for information) (1).
Low FODMAP Recipes with Mushrooms
Looking for a tasty low FODMAP Asian soup? Try this vegan hot and sour soup, which is packed full of flavour. You may notice a few ingredients you haven't seen in our app before. This recipe contains several newly tested foods to look out for in the new update. It even contains MUSHROOMS. I know what you’re thinking… mushrooms are not low FODMAP! However, canned mushrooms have been tested by Monash University and results show that they get the green light. This may be due to the processing methods in canning the mushrooms.
Vegan Hot and Sour Soup## Ingredients:
- Red chilli
- Garlic-infused oil
- Crushed ginger
- Canned champignon mushrooms
- Sesame oil
- Bamboo shoots
- Soy sauce
- Rice wine vinegar
- Balsamic vinegar
- Maple syrup (or brown sugar)
- Low FODMAP vegetable stock
- Cornflour
- Edamame beans
- Green spring onion tips
- Fresh chives
- Firm tofu
Instructions:
- Deseed and finely chop the red chilli (reserve a few slices as garnish), add more to taste if you prefer spicy food. Crush in a pestle and mortar with a pinch of salt, until it forms a very rough chunky paste. Then mix through the garlic-infused oil and crushed ginger.
- Drain the champignon mushrooms. Place in a sieve and wash well under running water.
- Heat a large wok or a large heavy based saucepan over medium-high heat. Add the sesame oil and the sliced mushroom.
- Drain the bamboo shoots, rinse under running water, and if needed slice into thin strips. Once the mushroom has browned, add the chilli paste and the bamboo shoots.
- Meanwhile, mix together the soy sauce, rice wine vinegar, balsamic vinegar, and maple syrup (or brown sugar) in a small bowl.
- Stir the mixture into the pan and cook for a minute, then pour in the low FODMAP vegetable stock. Reduce the heat to low.
- Dissolve the cornflour in 3 tablespoons of warm water and mix through the soup, and allow to simmer for about 3 minutes.
- Then add in the fresh edamame beans (let these simmer for about 6 minutes).
- While the soup simmers, finely chop the green spring onion tips and the fresh chives.
- About 1 minute before you are ready to serve, stir through the tofu (allow to warm).
- Season to taste with more soy sauce, vinegar or red chilli as needed. Then dish into bowls and garnish with the fresh chives, spring onion tips and red chilli slices.
Make sure you buy firm tofu stored in water (drain the water off). Normally champignon (button) mushrooms are high FODMAP, this means you need to buy canned champignon mushrooms in brine, which are lower in FODMAPs.