Is Lemon Low FODMAP?
Lemon is one of my favorite flavors. I love the smell of fresh lemon. It brightens my mood on even the dreariest days, sparking memories of a trip to the Italian island of Procida, where large lemons grow in abundance. You can imagine how happy I was, then, to learn that lemon fits nicely into a low FODMAP diet.
Lemon and lemon juice are low FODMAP at normal serving sizes. A medium lemon contains no excess fructose, while a tablespoon of fresh lemon juice has .01 grams of excess fructose, far below low FODMAP guidelines. In larger quantities, lemon juice may contain fructans, but evidence for this is sparse.
In this post we’ll look at the FODMAP content of lemon and lemon juice. It isn’t as straightforward as you’d think. That’s because most of the lemon juice sold in grocery stores is made from concentrate. And the concentrate making process changes the FODMAP content of the final product. Read on to learn more.
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FODMAPs in Lemon
Researchers generally agree that lemons and lemon juice are low FODMAP.
One study that analyzed nearly a dozen FODMAP food lists found that four included either lemon or lemon juice. All four report lemon and lemon juice are low FODMAP foods.1 Additionally, many reputable online sources, such as Mount Sinai hospital,2 include lemons on low FODMAP food lists.3
The FODMAPs of concern with regard to lemon are fructose and fructans. Like all fruit, lemon contains fructose, though in very small amounts.
However, it isn’t the amount of fructose in a food that determines whether it’s high or low FODMAP. Instead, FODMAP researchers look at the ratio of fructose to glucose. A food that contains more fructose than glucose is said to have excess fructose. It’s the amount of excess fructose that determines the FODMAP status of a food.
Typically, there should be no more than .40 grams of excess fructose per serving. If a food exceeds this guideline, it’s classified as high FODMAP. However, if there are two or more FODMAPs present in a food, the excess fructose threshold drops to .15 grams per serving.4
The following table shows the sugar composition of lemon, revealing that lemon doesn’t contain any excess fructose.
Sugar Content in Lemon
| Item | Size | Total Sugar (grams) | Sucrose (grams) | Glucose (grams) | Fructose (grams) |
|---|---|---|---|---|---|
| Lemon, medium | 2″ diameter | 1.45 | .35 | .58 | .52 |
Other FODMAPs in Lemon
I’ve found several websites that report lemon, or at least lemon juice, contains fructans in larger serving sizes. The primary source for this seems to be the Monash app. However, as I discussed in this post on FODMAPs in grapefruit, other sources don’t always agree with the app and I’m often unable to verify what’s reported in the app. This is the case with fructans in lemon and lemon juice.
I haven’t been able to find any additional research that supports the idea of significant amounts of fructans in lemons or lemon juice. This doesn’t necessarily undercut what the Monash app says. It simply means that this topic hasn’t been studied much.
However, there are online lists of high fructan foods from reputable sources that don’t include lemons.5 Even the Monash website doesn’t list lemons as high FODMAP.6 So, honestly, it’s a bit of head-scratcher.
The bottom line here is that there may or may not be fructans in lemon and lemon juice. However, my opinion is that this isn’t cause for great concern, for two reasons.
First, we generally don’t eat whole lemons, as we do other fruit like oranges and apples. Instead, we typically juice lemons. Or we may use small amounts of lemon in cooking or as garnish. So, even if lemon contains fructans, we likely aren’t eating enough lemon at any given time to ingest large quantities of them.
Second, the oft-cited Monash app states that lemon juice becomes moderate fructan at three-fourth cup servings.7 Unlike other fruit juices, most of us aren’t consuming three-fourths cup of lemon juice in one sitting. It’s unlikely, then, that we’re going to drink enough lemon juice at one time to ingest significant amounts of fructans.
Let’s turn our focus now to lemon juice, as that is the primary way people incorporate lemon into their diet.
Is Lemon Juice Low FODMAP?
The majority of lemon juice sold in grocery stores is not raw lemon juice, but rather is made from concentrate. Both freshly squeezed, raw lemon juice and lemon juice made from concentrate are low FODMAP at a normal serving size of one tablespoon.
However, fresh lemon juice contains excess fructose, while reconstituted (from concentrate) lemon juice doesn’t. This is because the process of concentrating lemon juice alters the FODMAP content.
FODMAPs in Raw Lemon Juice
The following table shows the sugar composition for a tablespoon of raw, freshly squeezed lemon juice. As you can see, there’s .02 grams of excess fructose in this amount of raw lemon juice.
Sugar Content in Raw Lemon Juice
| Item | Serving Size | Total Sugar (grams) | Sucrose (grams) | Glucose (grams) | Fructose (grams) | Excess Fructose (grams) |
|---|---|---|---|---|---|---|
| Lemon juice, raw | 1 tbsp | .39 | .07 | .15 | .17 | .02 |
If you’ve been reading along, you may be wondering why raw lemon juice has excess fructose when lemons themselves do not. That’s a good question. It has to do with how different FODMAPs act in water.
All FODMAPs, not just sugars like fructose and glucose, are water-soluble. This means they dissolve when they come into contact with water. But, some FODMAPs are more soluble than others. Among sugars, fructose is the most soluble. It will dissolve more easily in water than glucose or sucrose.8
Lemons themselves are 92% water, which is why they are a good juice fruit. When you juice a lemon, much of the easy to dissolve fructose come out in the juice. Glucose and sucrose come out, too, but these are less likely to dissolve. So, more of the glucose and sucrose will stay in the lemon pulp. This is why lemons in general have more glucose than fructose, while raw lemon juice has more fructose than glucose.
The ratio of glucose-to-fructose changes, however, when we’re talking about reconstituted lemon juice made from concentrate. Reconstituted lemon juice contains no excess fructose. How can that be? Let’s learn now.
FODMAPs in Reconstituted (from Concentrate) Lemon Juice
Most of the lemon juice sold in grocery stores is reconstituted juice. That means it’s made from concentrate that’s mixed with water. But, what is concentrate and why does it matter for FODMAP content?
Lemon juice concentrate is a thick syrup made from raw lemon juice. Juice is turned into concentrate by removing nearly all of the water.9 As we just learned, lemon juice contains more fructose than glucose, so when most of the water is removed, so is a lot of the fructose. This alters the fructose-to-glucose ratio. As a result, lemon juice concentrate contains less fructose than the raw lemon juice from which it’s made.
Sugar Content in Lemon Juice Made from Concentrate
| Item | Serving Size | Total Sugar (grams) | Glucose (grams) | Fructose (grams) |
|---|---|---|---|---|
| Lemon juice, bottled, from concentrate | 1 tbsp | .24 | .13 | .11 |
As shown in the above table, a tablespoon of lemon juice made from concentrate contains less sugar overall than raw lemon juice and also contains no excess fructose. Some glucose is lost in the concentrate making process, but the loss of fructose is more notable.
You may also see that the sucrose present in raw lemon juice has disappeared. Sucrose is a combination of fructose and glucose. It’s likely that sucrose breaks down during the concentrate making process, so is represented in the glucose and fructose numbers.
Conclusion: Lemon and Lemon Juice are Low FODMAP
If you’re eating low FODMAP, citrus fruits are generally a safe option and lemon is no exception. Lemon, as well as lemon juice, contains very little fructose. Lemon may contain fructans, but there’s not a lot of research to support this. Even if fructans are present in lemon and lemon juice, you would need to consume unreasonably large serving sizes to ingest significant amounts of fructans.
At this point you may be wondering about lemonade. Lemonade is generally low FODMAP. Homemade lemonade recipes typically call for large amounts of sugar, which results in high amounts of sucrose in the finished product. Packaged lemonade mixes and refrigerated lemonades also typically have large amounts of sucrose, unless they use artificial sweeteners. So, while lemonade is generally high in sugar, it’s typically lower in fructose.
Posts Related to “Are Lemons Low FODMAP?”
As mentioned, citrus fruits are generally a good bet for those needing to eat low fructose and/or low FODMAP. I’ve written a few other posts on citrus fruits.
This post looks at whether grapefruit is low FODMAP. As with lemon, grapefruit is low fructose, but there’s debate about whether it contains fructans.
And this post looks specifically at the fructose content of oranges. Many types of oranges are low fructose, but just remember that low fructose doesn’t always mean low FODMAP.
While lemons are low FODMAP and low fructose, I didn’t include them in my list of low fructose fruits. That’s because we don’t typically eat whole lemons. But if you’re interested in other low fructose fruits, this is the post for you.
If you’re interested in juices you can actually drink, here’s my post on low FODMAP juices. Just be aware that most juices aren’t low FODMAP and there’s debate about some of the ones I’ve classified as 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.
