Are Mushrooms Low FODMAP? (Yes, Oyster Mushrooms Only)

Michael Eisenwasser 6 min read

Most common mushrooms are high FODMAP. Oyster mushrooms are the exception, and they work as a direct swap in almost any recipe. That one swap is the difference between mushrooms being off the menu during elimination and being a regular part of dinner.

If you've just started the low-FODMAP diet, the mushroom situation looks bleak. Button, cremini, portobello, and Swiss brown mushrooms are all high FODMAP. That takes out most supermarket packs of pre-sliced "cooking mushrooms" in one stroke. But oyster mushrooms rate low at a generous serve, and canned champignons clear the elimination phase too. Between those two options, mushroom risotto, pasta, and stir-fries all stay on the table.

The short answer

Here's the mushroom cheat sheet for the elimination phase:

• Oyster mushrooms: low FODMAP at a 1-cup serve (Monash-rated). Your main choice.
• Canned champignons, drained: low FODMAP at a small serve. Pantry backup.
• Button, cremini, portobello, Swiss brown: high FODMAP at typical serves. Skip during elimination.
• Shiitake (fresh): high FODMAP at typical serves. Dried shiitake is low at a very small serve.
• Enoki: high FODMAP at typical serves.

Always check the Monash app for the current rating, because ratings do get updated. But the oyster-mushroom-as-default pattern has held for years and it's a safe default while you learn your triggers.

Why most mushrooms are a problem

The FODMAP issue with mushrooms is mannitol. Mannitol is a polyol, a sugar alcohol, and it's the "P" in FODMAP. The small intestine absorbs polyols slowly and incompletely. What doesn't get absorbed moves into the large intestine, pulls water in along with it, and gets fermented by gut bacteria. That's what drives the bloating, cramping, and loose stools people get from high-mannitol foods.

Mushrooms concentrate mannitol naturally. A cup of button mushrooms has enough to cross the threshold for most people with IBS. Cremini and portobello are the same species as button mushrooms (Agaricus bisporus) at different maturity stages, so they share the same mannitol problem. Swiss brown is another name for cremini in some countries. Fresh shiitake and enoki fall into the high-FODMAP group for similar polyol reasons.

For a fuller explanation of what the F, O, D, M, A, and P actually stand for, see our primer on what FODMAPs are.

Why oyster mushrooms are different

Oyster mushrooms are a completely different species (Pleurotus ostreatus). Monash has tested them and rated them low FODMAP at a 1-cup cooked serve. That's a real portion, not a garnish. You can put actual mushrooms in your pasta and not worry about it.

Very large serves do start to push into moderate or high-FODMAP territory for polyols, so check the Monash app for the current thresholds. For elimination-phase cooking, 1 cup is plenty for one person in a bowl of pasta, a stir-fry, or a risotto.

Oysters also hold up well in cooking. They have a meatier texture than button mushrooms, a gentle savory flavor, and they brown nicely. If you were using button mushrooms for umami and body, oyster mushrooms do the same job.

Canned champignons: the pantry loophole

Fresh button mushrooms are high FODMAP, but canned champignons (drained) are low FODMAP at a small serve. The reason is simple: mannitol is water soluble. When mushrooms sit in brine for weeks during canning, a chunk of the mannitol leaches out into the liquid. Drain that liquid and you've drained a lot of the FODMAPs with it.

The catch is that this only works if you actually drain them. Giving them a quick rinse under cold water on top of draining is a reasonable extra step. Don't pour the canning liquid into the pan and call it a sauce.

Canned champignons are a practical backup when you can't find oyster mushrooms (they're still not in every supermarket) or when you want something shelf-stable for a weeknight dinner. Texture is softer than fresh, so they work better in saucy dishes than in a sear.

The variable ones: shiitake and enoki

Dried shiitake has a low-FODMAP rating at a very small serve, about enough to flavor a broth or a small stir-fry, not enough to be the main ingredient. Check the Monash app for the current gram amount. Fresh shiitake is high FODMAP at typical serves and should stay out during elimination. The soaking liquid from rehydrating dried shiitake contains leached FODMAPs, so don't pour that into your broth either.

Enoki is high FODMAP as of current Monash testing. The long thin white clumps you see in ramen and hot pot are out for elimination.

These are the mushrooms most people mix up, because the fresh and dried versions rate differently, and because enoki and oyster sit near each other at the grocery store. Read the label, or stick with oyster as your default.

FODMAP stacking: watch the polyols

Mannitol is in mushrooms, but sorbitol and mannitol together show up across a lot of foods. Sweet potato, celery, sugar-free gum, and stone fruit all add to the polyol load. Avocado brings its own polyol, perseitol, which is expected to behave similarly (see our avocado post for more on that).

If you stack several of these in one meal, each at a "safe" serve, you can still end up with symptoms. This is FODMAP stacking, and polyols are one of the groups where it catches people out most often. A 1-cup serve of oyster mushrooms plus a small serve of avocado plus a handful of sweet potato fries is three polyol hits in one meal. Individually fine, together often not.

For elimination, I keep mushrooms in one dish per day, not spread across breakfast, lunch, and dinner.

Direct swaps in the recipes you already cook

You don't have to rewrite your cooking. A few patterns:

• Stir-fries. Slice oyster mushrooms into strips, sear hard in a hot pan, add near the end. They absorb soy sauce or tamari well. Skip garlic and onion, use garlic-infused oil and the green tops of scallions.
• Pasta. Sautéed oyster mushrooms with garlic-infused olive oil, salt, black pepper, and parsley make a weekday pasta. Add a handful of spinach at the end.
• Risotto. Use oyster mushrooms instead of cremini. Cook the rice in a low-FODMAP stock and finish with parmesan.
• Soups and stews. Add oyster mushrooms in the last 10 to 15 minutes so they keep some bite. Canned champignons (drained) work here too if you want something softer.
• Omelets. A small handful of sliced oyster mushrooms cooked in butter before adding eggs.

For more produce that stays in during elimination, see our low-FODMAP vegetable list. For full recipes, browse our low-FODMAP recipes.

Hidden sources to watch

• Mushroom stock cubes and extract seasonings usually use button or cremini. Unless the label specifies oyster, assume high FODMAP.
• Restaurant mushroom dishes. A mushroom pasta at a restaurant is almost certainly cremini or a button mix, and the sauce is built on onion and garlic. Order something else and save mushrooms for home.
• Mixed mushroom packs. "Wild mushroom mix" at the supermarket usually contains high-FODMAP varieties. Buy single-variety oyster instead.

The one-line version

Buy oyster mushrooms. Keep a can of drained champignons in the pantry as backup. Skip button, cremini, portobello, fresh shiitake, and enoki during elimination. Reintroduce polyols after the elimination phase to find out what your actual tolerance looks like, and test fresh button mushrooms then if you want them back.

Mushrooms aren't off the menu on low FODMAP. You just need to know which one to buy.

Track your symptoms and discover patterns with FODMAP Tracker. Includes a database of 1,000+ foods with FODMAP ratings.