Blueberries do often cause excessive gas, especially when you eat a relatively large serving.
There’s a few different aspects of blueberries that can cause gas, but the main issue for most is that they are very high in fructose.
I’m going to go over the whole picture so that you can understand why a large serving of blueberries may cause you gas issues, and then you can adjust your serving size accordingly.
Table of Contents
Why Do Fruits Like Blueberries Cause Gas?
Certain fruits are known to cause gas and be good for bowel movements.
This is because they contain certain carbohydrates that are hard to digest.
These carbohydrates pass through the stomach and small intestine mostly intact, and then are fermented by your gut bacteria in the large intestine. This process produces various gasses as a byproduct.
So what are those carbohydrates that don’t digest well? The most notable ones are:
- Fiber
- FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) – Note that some of these are considered fiber as well.
Now we can look at how much of these are in blueberries.
Fiber Content of Blueberries
Blueberries are reasonably high in fiber, although the bigger danger is that it’s easy to eat several servings of blueberries in one sitting.
The nutrition data below is for 100 grams of blueberries, which is about 2/3 cup.
| Blueberries | |
|---|---|
| Energy (kcal) | 57 |
| Protein (g) | 0.74 |
| Total Lipid (g) | 0.33 |
| Carbohydrate (g) | 14.5 |
| Fiber (g) | 2.4 |
| Sugars (g) | 9.96 |
That amount of fiber alone typically isn’t an issue.
Even if you ate 500 grams of blueberries, that’s about 12 grams of fiber, which may cause some gas, but shouldn’t be a huge problem.
The bigger issue is actually found when we look at the high amount of certain sugars in blueberries.
Hard to Digest Carbohydrates in Blueberries
We’re not going to go over every single FODMAP here, but there are a few that are found in significant amounts in blueberries:
- Fructose
- Sorbitol (a sugar alcohol)
- Fructooligosaccharides (FOS)
I was able to find a study that measured FODMAP levels in blueberries, which are shown in the table below per 100 gram serving.
Note that the sugars don’t add up to the exact weight in the nutrition information above, but it’s a fairly minor difference (likely just natural variation among blueberry crops).
| Blueberries | |
|---|---|
| Moisture | 85 g |
| Fructose | 5.87 g |
| Glucose | 10.64 g |
| Sucrose | 0.78 g |
| Sorbitol | 0.96 g |
| Total FOS | 0.50 g |
Most of the sugar in blueberries is glucose, which is very easy to digest.
However, I’ve highlighted 3 potential issues.
FOS are not likely to cause a huge issue here unless you eat several servings, so we’ll gloss over those.
But sorbitol intolerance can lead to gastrointestinal issues in as little as 5 grams of sorbitol. It is certainly possible to eat 500 grams of blueberries at once, and people who are sensitive to sorbitol may have issues as a result.
Finally, blueberries are a high fructose food.
According to current research, just about everyone can absorb 15 grams of fructose in a sitting. However, past that amount, a significant amount of people have trouble breaking it down (i.e. it will get fermented). You can reach that threshold of fructose in blueberries with just a few servings.
These Carbohydrates Do Not Act Alone
We saw that just a few servings of blueberries may be an issue for certain people because of its high fructose content or sorbitol.
But even for people who tolerate those pretty well, there’s still a lot of fermentation occurring when you consider everything together:
- Fiber
- Fructose
- Sorbitol
- FOS
In other words, some people will get gas from just a single serving of blueberries (1 cup or less).
Even though some people will tolerate some of those carbohydrates better than others, it’s probably not advisable to eat more than a few cups of blueberries at once.
