Did you know colorful little grapes are one of the most controversial fruits in the FODMAP world? Well, now you do. Whether grapes are low FODMAP depends on who you ask. And, while you didn’t technically ask me, you’re here. So let me tell it to you straight.
Grapes are not low FODMAP at normal serving sizes. A half cup of green grapes has 1.30 grams of excess fructose. A half cup of red grapes has 1.13 grams of excess fructose. Both of these exceed the low FODMAP threshold of .40 grams of excess fructose per serving.
I realize this contradicts what you may have heard. I know a lot of online sources say that grapes are low FODMAP. But truly, they aren’t. Let’s look at why that is now.
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Low FODMAP Serving Sizes
A question that comes up often is how much (or little) of a food is low FODMAP. So, I thought now would be a good time to look at low FODMAP serving sizes.
There are a lot of websites that claim to tell you whether certain foods are low FODMAP. In my experience, these sites mostly just repeat data from the Monash app. Since the Monash app lists low FODMAP serving sizes for many foods, these websites tell you that the foods are low FODMAP. But that’s a misinterpretation of the information given by the app.
The Monash app doesn’t tell you which foods are low FODMAP. Instead, it tells you at what serving size foods fit into low FODMAP guidelines. Any high FODMAP food can be made low FODMAP if you reduce the serving size enough. This is why the Monash app often lists very small serving sizes for certain foods.
How Many Grapes are Low FODMAP?
Let’s use grapes as an example here. When I began doing research for this post, I ran across many websites that assured me that grapes are low FODMAP. When I read further, I realized what they really mean is that the Monash app lists a low FODMAP serving size for grapes.
Most report that, per the Monash app, a serving of 6 grapes is low FODMAP.1 Again, the normal serving size for fresh fruit is half a cup. So, you’d have to eat much less than a normal serving of grapes to stay within low FODMAP guidelines.
By the way, you should know that the original low FODMAP guidelines are based on standard serving sizes typically consumed in one meal or in one sitting. For example, these guidelines state that a standard serving of fruit should have between .15 and .40 grams of excess fructose.2 And a standard serving is one small piece of fruit or one half cup of fruit pieces. Not 5 grams of pear. Not 6 grapes.
Some bloggers’ over-reliance on the Monash app contributes to the the confusion about which foods are and aren’t low FODMAP. Simply copying data from the app distorts FODMAP research and misleads people into thinking that lots of foods are low FODMAP when, in fact, they aren’t.
Now that we know why there’s disagreement on whether grapes are low FODMAP, let’s dig into some research data. I’m located in the United States, so my data comes from the US Department of Agriculture (USDA). Fortunately, the USDA has tested grapes fairly recently, publishing new data on grapes in 2022. Let’s learn a bit about grapes and then see what the data says.
Are Green Grapes Low FODMAP?
Though often associated with Mediterranean climates, many types of grapes are grown in the United States. The majority of US-grown grapes are wine grapes. According to the USDA, over 70% of grapes grown in the US are used to make wine.3
The most popular variety of juice grape in the United States, the Concord, is grown around the Great Lakes.4 Sultanas, also known as Thompson seedless grapes, are grown in California. Sultanas are the most common type of green grape sold in US grocery stores.5
Both green and red grapes are a good source of Vitamin A and Vitamin C and are rich in antioxidants.6 Both types also contain the polyphenol resveratrol, which has many health benefits, including anti-cancer and anti-inflammatory properties.7
However, red grapes have an advantage when it comes to antioxidants. This is because red grapes contain anthocyanins, antioxidants that give grapes, along with blueberries and purple cabbage, their distinct colors.8 Green and red grapes have similar nutritional profiles, too, containing about the same amount of calories. However, fructose content does vary slightly between green and red grapes.
The following table breaks down the sugar content in green grapes, with a focus on excess fructose. The data comes from a sample of 8 bunches of green grapes tested by the US Department of Agriculture in 2021 and 2022. (You can read more about the individual samples here, if you wish.)
Fructose in Green Grapes
As shown, a half cup of green grapes has 1.30 grams of excess fructose. This far exceeds the low FODMAP threshold of .15 to .40 grams of fructose per serving that’s suggested by low FODMAP researchers.
Based on these figures, it’s clear that green grapes are not a low FODMAP food. Can green grapes be made low FODMAP if you reduce the serving size enough? Sure.
A half cup of contains, on average, 16 grapes.9 This means each green grape has about .08 grams of excess fructose, which in turn means you could eat about 5 grapes and stay within the higher low FODMAP guideline of .40 grams of excess fructose. That’s pretty close to the 6 grape serving size recommended by Monash.
But again, just because a low FODMAP serving size exists doesn’t make green grapes a low FODMAP food. At normal, adult serving sizes, grapes have a large amount of excess fructose. This is why grapes appear on this list I created of high fructose fruits. The list is fairly short and grapes are at the top.
Are Red Grapes Low FODMAP?
Red grapes sold in US grocery stores are usually the Crimson seedless variety, which first appeared on the food scene in 1989.10 Red grapes and green grapes are very similar, but there are two notable differences: color and sugar content.
Crimson grapes get their name from their distinct reddish-purple color, which can range from light to dark. These grapes owe their color to the presence of anthocyanins, which are also found in plums and other reddish-purple fruits and vegetables. Anthocyanins give red grapes a slight nutritional advantage over green grapes, since anthocyanins have been shown to have anti-diabetic, anti-inflammatory and anti-cancer properties.11
Another difference between red and green grapes is sugar content. On average, red grapes have a slightly higher sugar content than green grapes. The following table provides a full break down of the sugar content in red grapes, again with an emphasis on fructose.
Fructose in Red Grapes
As shown, while red grapes have more total sugar than green grapes, they have slightly less excess fructose. Nonetheless, a half cup of fresh red grapes still far exceeds the higher low FODMAP threshold of .40 grams of excess fructose per serving.
Conclusion: Grapes are High Fructose and NOT Low FODMAP
Despite assertions otherwise, grapes are not a low FODMAP food. A normal half cup serving of grapes contains between 1.13 and 1.30 grams of excess fructose, way beyond the amount suggested by low FODMAP researchers.
In addition, grapes have some of the highest fructose values of any fruit, making them particularly problematic for people with fructose malabsorption.
This doesn’t mean you have to entirely avoid grapes. I don’t believe in completely restricting any food unless you have a true allergy. I just want you to understand that, at normal serving sizes, grapes aren’t low FODMAP.
You can reduce the serving size to bring grapes into alignment with low FODMAP guidelines. And, if you like grapes, it may be worth doing that. Especially for red grapes, since they have greater health benefits.
However, if you’re like me and have major problems digesting fructose, it might be best to just stick with lower fructose fruits. I have a long list of those, which I’ve linked to below.
Posts Related to “Are Grapes Low FODMAP?”
As mentioned, grapes are very high in fructose. You can learn more in this post on fruits high in fructose.
If you’re thinking of replacing grapes with another fruit, I have a fairly large list of low and moderate fructose fruits. Just remember that low fructose doesn’t necessarily mean low FODMAP and that, as we learned here, serving size matters a lot. I focus on standard serving sizes, which is what you’ll find in this post on low fructose fruits.
And, as I mentioned at the outset, the FODMAP content of grapes is a bit controversial. So is the FODMAP content of raisins. You can learn more about that is this post I wrote on whether raisins are low FODMAP.
About the Author
Amanda Coleman, PhD, studies food culture and teaches a popular Food and Society course. Years of digestive problems led her to live low FODMAP. Now she uses her research and analysis skills to help others understand FODMAP essentials, so they can lead better, healthier lives.
Disclaimer: the author is not a certified medical professional. Opinions expressed and content contained on this website are for informational purposes only and should not be interpreted as medical advice. Exercise caution and due diligence when using this site and the information contained herein and understand your experiences may vary.