If you find that eating mushrooms leaves you bloated shortly afterwards, you’re not alone. Mushrooms are one of the many foods that can cause gas – but, if you’ve ever wondered why, and if there’s anything you can do to stop it, this is the post for you.
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Why Do Mushrooms Cause Gas?
The main reason why mushrooms cause gas is that they contain manitol, one of a group of substances known as sugar alcohols that can ferment in your large intestine causing gas.
Now, just because the word alcohol is used, that doesn’t mean you can get giddy on mushrooms (well, not the supermarket type of mushroom anyway), sugar alcohols don’t actually have anything to do with booze.
They get the name alcohol because of their chemical compostion (if you want the full science, then this is a good primer) rather than because they can get you drunk.
Sugar alcohols are most commonly used as sweeteners – sorbitol, xylitol and erythritol are all examples you might be familiar with – but, they are also found naturally in many fruits and vegetables – including mushrooms – and this the most common reason why mushrooms can lead you to produce gas.
You see, mannitol, and the other sugar alcohols, are what’s known as FODMAPs.
What The Heck are FODMAPs?
The name is a shortened version of their super-snappy full title – Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols – and they are a very common cause of excess gas.
Mannitol is one of the polyol group that make-up the P in FODMAP.
‘Unlike most of the foods we eat, the sugars in FODMAPs can’t be digested by the body,’ explains gastroenterologist Professor Peter Whorwell, author of Take Control of Your IBS.
He explains that, when FODMAPs enter your large intestine, the gut bacteria that live there then use them as fuel. As they do this they produce chemicals that can irritate the gut lining and make gas.
Not everyone finds this gas a problem, most of us pass gas up to 30 times a day often without noticing, but, in people with a sensitive digestive system (aka irritable bowel syndrome or IBS), the gas can be plentiful and also cause digestive issues like bloating, gas pain/abdominal pain or cramps.
How to Prevent Getting Gassy From Mushrooms
While some people who experience painful gas and bloating after eating mushrooms may have to cut them out of their diet (more on that in a minute), if your wind or bloating is more embarrassing than uncomfortable, there are also a few ways you can help reduce the risk of mushrooms causing digestive symptoms.
Firstly, pick types of mushrooms that have lower mannitol levels – the lowest levels are found in oyster mushrooms, while button mushrooms are more likely to cause gas and bloating as they contain the highest amounts of this natural sugar.
There’s a good guide as to exactly which mushrooms have the highest potential for gas production here.
Cook Your Mushrooms
Mannitol is water soluble so you might find that cooking mushrooms in water reduces some of the sugar content and also their bloat potential.
For the same reason, if your find you only fart after eating raw mushrooms, you might want to try cooking your mushrooms to see if this helps.
Raw food of any kind can generally be a bit harder for the body to breakdown – and this alone can mean it produces gas as it spends more time in the intestinal tract.
Chew Your Mushrooms Well
If you don’t chew any food well it leaves the stomach and arrives in the small intestine in larger chunks than it should.
Again, this means it takes it longer for the digestive tract to break it down – and the longer food hangs around the gut, the more chance the gut bacteria have to work on it and produce excessive gas.
Eat Your Mushies Slowly
If you bolt food down you swallow air and this can trigger bloating (also a common reason why people bloat after doing exercise). Rushing your mushies could see them being blamed for causing gas when they actually have nothing to do with it!
Avoid a Gas Pile On
There are a number of other foods that have a reputation for causing gas – beans, lentils, cruciferous vegetables like broccoli or cauliflower – even chia seeds.
The more of these foods there are in a meal, the more gas will be produced and, you might tip into the threshold where a little bit of wind becomes a lot, leading to gas pains or other unpleasant symptoms.
Before you give up mushrooms completely, make sure you’re not eating them on combinations that overload your system
Switch Up Your Meals
One of the biggest problems when trying to work out if a food is a cause of bloating or not, is that people are creatures of habit. We tend to eat the same meals over and over again.
What this can mean is that while you might think that mushrooms cause gas and bloating – actually it’s the fact that you always have them on toast (and toasted frozen bread is actually a very underrated cause of bloating) that’s triggering your upset stomach.
Which brings us to a very important issue…
How to Tell if Mushrooms are Causing Your Gas
After all, most of us don’t tend to eat one food at a time. So, how do you know that eating mushrooms is actually what’s causing you to produce gas?
The number one way to determine this would be to keep a food diary.
These help you spot patterns between what you’ve eaten and any resulting symptoms.
For some tips on how to keep a good food diary, check out our post on how to keep a good food diary here
You can also download some templates that help you here.
If you do find that you start to get gas or bloating within a few hours of eating mushrooms, then start with the tips above to see if this helps.
If it doesn’t, or, your food diary shows you that your symptoms are also triggered by other foods that contain mannitol (cauliflower and snowpeas are also high in mannitol), you might need to look at reducing the FODMAP levels of your diet.
This isn’t something that you should do completely alone as it’s very complex to cut high FODMAP food out of a diet without blaming the wrong things, or, cutting out healthy food that you perhaps don’t need to, so, if you’re thinking about it, then, read the book The Complete Low FODMAP Diet by doctors Sue Shepherd and Peter Gibson which explains exactly how you should start thinking about altering your diet in this way.
Find The Complete Low FODMAP diet book here.
The book is written by the team that discovered the link between FODMAPs and IBS symptoms like gas and bloating and they clearly explain about how to try and find which FODMAPs might be causing your digestive issues – and in what amounts you might be able to tolerate them.
Should You Stop Eating Mushrooms?
Mushrooms are actually pretty healthy foods..
In fact, according to a famous study at Tufts University, even just a handful of button mushrooms has the ability to improve immune function – and other mushrooms are also known for having effects on immunity.
On top of this, according to researchers at Penn State University people who regularly eat mushrooms can find their mood improves. They say the vitamin D, B vitamins and antioxidants found in mushrooms might all play a role in mental health symptoms.
Mushrooms might also help with weight loss if you use them as a substitute for meat. They contain few calories (just 22 per 100g) so swapping them for all, or even just some, of the meat in a dish can reduce your calorie intake.
In one study, where people tried this swap for four days, they cut their calories by 420 and their fat intake by 30g.
So, unless your digestive health is really upset by mushrooms, it’s better to try and keep them in your diet and just handle the gas instead.
Quick Ways to Reduce Mushroom Bloating
Good ways to release gas in your system and reduce bloating include drinking peppermint tea which helps deflate bloating, gentle exercise helps move gas through the system (vigorous exercise can actually cause the opposite though) and the yoga pose, child pose, or rest pose as you’ll know if you do Pilates, also relaxes the gut in a way that encourages the movement of air.
Find our how to do child pose here.
We’ve got some other suggestions in our post on tips to release gas and bloating here.
So, there you have it a quick guide as to why mushrooms make you gassy and, how to reduce your risk. Remember though if your gas worries you, you notice any changes in your bowel habits, or if you get bloating that doesn’t go away, please do see a doctor just to check there’s not something else going on.
Who is The Wellness Nerd?
My name is Helen Foster and I’m a health journalist and wellness author. Publications I’ve written for include Women’s Health, Reader’s Digest, Body and Soul, Good Health at the Daily Mail and more. I have also written 16 books on health and nutrition.