Why Do Onions Make you Fart? | 8 Great Cures for Flatulence

Yep, we are back there again! The unpleasant side effects to a good curry. Indian food is super tasty, yet we can all be left feeling the effects the next day. Curries use a lot of one ingredient… Onions! And while they taste great, they can produce some unwanted side effects. Today we will look at answering the question, why do onions make you fart? And give some really effective solutions to reduce tummy trouble.

Quick Answer | Why Do Onions Make You Fart?

Onions are full of a certain type of sugar called fructans. Fructans react with your inner gut flora and create lots of gas. Also, all vegetables are alkalising, when they mix with your stomach acid it produces a bubbling reaction. Think of it a little like dropping bicarbonate of soda in a jar of vinegar.

Here’s a quick video to demonstrate the kind of effect we are talking about

Do Onions Cause Stomach Gas? | Curry and What You Need to Know...

If you didn’t think there are onions in curry then its time to think again. Most types of curry dishes contain onions, even if you can’t see them…


Hell yes.

Most curries you’ll eat are made with an onion base gravy. It is made up almost entirely of onions, along with a few other vegetables, and often some other spices (which can also cause flatulence… We are looking at you Mr. Chilli)

But back to the matter at hand. Why do onions make you fart?

Well, it bubbles down to a couple of things (pun intended)…


Here’s something surprising. Onions are high in a type of sugar called fructose. You’ll find fructose in plenty of other fruits and vegetables. Fructose is a naturally occurring sugar. Sugars cannot be fully absorbed by the body, meaning they are present in your digestive tract all the way to the end of the line.

When you eat onions they take a little time to work their way through your system. While they are ‘on the way down’ they react with the bacteria found in your gut. Sugars are an ideal food for fermentation. A byproduct of this process is the production of gas.

You know what another name is for ‘gas’ found in your gut? Or… More appropriately, gas that makes its way out of your gut?

That’s right.



If you are suffering from a ‘gas attack’ after eating a food full of onions, like a good curry, then you might notice another attribute.

In fact, other people might just notice it too. 

Onions also happen to be really high in sulphurous compounds. Sulphur tends to smell quite bad, so it stands to reason that any ‘byproduct’, released as these compounds are digested, will smell quite bad too. 

Often, along with ring sting, you’ll find that your ‘emissions’ aren’t exactly the sweetest smelling things around.

Disgusting, right?

Listen, just blame it on the dog.

Farts Man pinching his nose

Mixing Acids and Alkalines

Most of you will already know that your stomach contains acid. This is what dissolves and breaks down food once you have eaten it.

Onions, like most vegetables happen to be an alkaline. When you combine an acid with an alkaline you get a fizzing and bubbling reaction. If you’ve ever added a mentos mint to a bottle of cola you’ll have seen a strong reaction. Imagine this happening on a smaller scale in your stomach and it is easy to see why you might feel a little gassy after eating so many onions.

Are Foods That Make You Fart Bad for You?

Absolutely not.

Medical data shows that the average human farts between 5 and 15 times per day (amateurs)! If you were to hold this in it can actually be pretty bad for you, not to mention that it is quite painful.

Farting is a normal part of digestion. The millions upon millions of bacteria located in your gut go to work on all foodstuffs. As they work away on breaking down the food, they produce gas as a byproduct which eventually works its way out.

In fact, fructans can be really good for you. They feed the ‘good’ bacteria located in your gut.

Foods that make you fart are not bad for you, it is an entirely normal process (even if the other half doesn’t think so).

How do You Avoid Gas from Onions?

Alright, so you aren’t going to give up on foods containing plenty of onions, so we are going to have to come up with a few solutions.

Here are some top tips to avoiding gas from onions and what you can do to make life a little less fragrant…

1) Try to Avoid Raw Onions...

Any food which is eaten raw is harder for the body to break down. This means it will have a greater effect, especially when it comes to flatulence…

The answer?

Cook your onions. If they are in a curry then this should be the case anyway. When would you eat raw onions with Indian food?

Well, freshly fried poppadoms are traditionally served with a raw onion salsa, give this a miss especially if you are going to be in company in the near future.

2) Eat Other foods that Reduce Gas...

Here’s the good news. Curry often contains other ingredients that work to reduce the effects of those pesky onions.

What do I mean?

Tomatoes contain tonnes of Potassium, which helps to reduce bloating.

Another great way to reduce gas is to eat plenty of rice. Rice is very easily digested, and is a great source of fibre, keeping you regular without any blockages. Easy in, easy out!

3) Try and Stay Away from Fizzy Drinks...

We have already seen that onions produce a fizzing effect in the stomach and lead to the creation excessive gas. 

Fizzy drinks like soda or beer both contain added carbon dioxide (as well as pesky sugars). By adding to the gas in your stomach you are only going to make a bad problem worse.

4) Eat Slower and Take Smaller Bites...

Look, I get it.

You have a plate full of delicious Dopiaza in front of you and you are hungry…

Coincidentally ‘Dopiaza’ means ‘Double Onions’…

If you take smaller bites and eat slower you are not going to be adding extra air to your gut as you swallow. Once that air has made its way in, it has to find a way out. Generally this happens in one of two ways, neither of which is pleasant, or polite.

5) Drink Peppermint Tea...

Peppermint tea is absolutely amazing for reducing bloating. Mint contains oils that relax your gut slightly, they also aid in dissipating a build-up of noxious gasses.

A curry followed by a cuppa?

Sounds great to us!

6) Avoid Gas from Other ‘Contributors’...

What do I mean by ‘other contributors’? 

Well if you are a fan of Dhansak then you’ll be in for double trouble, as it also contains an awful lot of lentils.

Lentils, are similar to onions in a way. They also contain a type of fructan that increases the likelihood of a bottom-burp!

7) Use Medication...

Listen, if you love onion based curries as much as I do then you might have to resort to a few secret weapons.

Like what?

Well you can easily buy supplements that reduce the likelihood of a ‘blow out’. There are plenty of products like Beano or others such as Windsettlers that reduce the amount of gas caused by eating onion based foods.

There are plenty of other anti-gas options available too!

8) Anti Fart Pants?

Alright, perhaps not too serious, but when you’ve gotta go, you’ve got to go! Just because you have eaten too many onions doesn’t mean everyone else has to suffer!

Think I’m joking?

Check these out…

Final Thoughts | Why Do Onions Make You Fart?

Onions are tasty and a key ingredient to many Indian dishes. Why do onions make your fart? They cause reactions in your gut. They are full of naturally occurring sugars that react with your gut biome to make excessive gas. They are also sulphurous, so that gas is gonna stink! Using a combination of the above tactics you should be able to limit any toxic emissions. Now you are armed with the knowledge, why not check out some of my delicious onion based curry recipes… Have you tried anti fart pants? Let me know in the comments!

Enjoy Making Curry Yourself?

Hey folks, thanks for reading this article. I hope you found it useful, and that you learned something new allowing you to make your curry extra special. Here are a few things that can really elevate your curry game to the next level. 

These are affiliate links, so if you use them I receive a small commission, but this won't cost you any extra. In all honesty, I use very similar items myself, and wouldn't hesitate to recommend them to my friends.

A Complete Curry Kit: - Literally, everything you'll need to make curry all in one place. Cookware, storage, utensils, even the spices! This is my dedicated guide to getting you up and running all for the price of few takeaways.

Curry pans: - You need one, and one only. A frying pan exactly like this is really easy to use, and is exactly the type that authentic Indian chefs use to make the type of curry that you'll have in your local takeaway. You can see my full reviews of several pans right here...

Spice Storage: - Being organised is half the battle in making great curry. Spices can be notoriously hard to keep tidy. That's why I tend to use a spice rack like this. You can arrange your spices by size, heat, or any way you choose. I've got a detailed review of several Indian spice racks in this guide.

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