Does Flaxseed Cause Gas? (It Can, Here’s How…)


The short answer is that yes, flaxseed can cause gas! Typically, it’s not excessive, but in some people it’s worse than others.

There are a couple of ways this can happen, I’ll go through each one quickly.

If none of these seem like the cause of your gas, it could be something else in your diet.

High Fiber in Flaxseed Can Cause Gas

flaxseed package

Gas is produced when fiber or certain carbohydrates ferment in your large intestine (your small intestine can’t digest them fast enough).

Bacteria can digest some of that gas, but if you’re introducing more fiber to your diet than you’re used to, most of that gas has to come out a different way.

Take a look at the main nutrients in flaxseed:

Nutrient Amount (in 100 g flaxseed)
Calories 534
Carbohydrates 28.9 g
Fiber 27.3 g
Fat 42.2 g
Protein 18.3 g

Almost a quarter of flaxseed by weight is fiber! In fact, basically all the carbohydrates are fiber, which is why it can still be eaten by those on a keto diet.

If you’re just having a teaspoon of flaxseed, it’s probably not an issue, but if you’re eating a couple tablespoons or more it could be.

Over time, your gut should get better at digesting it (usually take a few weeks of regular consumption for this adjustment to take place).

Side note: If you’re eating whole flaxseed, make sure to chew them well. Your body can’t digest them if the shell is fully in tact.


Fiber is known to cause gas, and flaxseed has a ton of fiber. If you’ve recently started eating more flax, limit how much you eat while your gut adapts to the extra fiber.

Flaxseed Can Go Bad

The other potential issue, which I’ve experienced first hand, is that ground flax can go bad fairly easily.

block of ground flax

If exposed to any air or moisture, it goes bad quite quick. You can tell either because it starts to clump together, or because it starts to smell weird.

You should store it in the fridge if you buy flax in amounts that take you more than a few weeks to eat.

Personally, it took me a while to recognize that some flax I had went bad and was causing gas and other stomach issues.

If you’re noticing stomach pains and discomfort as well, that could be a sign your flax is rancid.


If you think your flaxseed might have gone bad, get some fresh flax and test it for a few days to see if your flatulence disappears.

About the author

Dale Cudmore

Your friendly neighborhood vegan from Toronto. Chemical engineer turned semi-professional soccer player and freelance nutrition writer. I've been vegan for years and try to make life easier for others by sharing what I've learned.