Nuts with IBS and nut allergies: FODMAPs, peanuts, tree nuts and coconut

For IBS, it depends on the nut and the portion. Monash University lists cashews and pistachios as high FODMAP, and macadamias, peanuts and walnuts as low FODMAP choices, with GOS and fructans as the main FODMAPs in nuts. For a nut allergy, the answer is "No" for the nuts you are allergic to, and cross-contact means even nuts you aren’t allergic to need care.

Nuts and seeds bring fiber, protein and plenty of flavor, so it is worth knowing which ones suit you. This guide covers FODMAPs at the level Monash publishes, the difference between peanut and tree nut allergy, the FDA’s change on coconut, and how to shop and eat out with a nut allergy.

With a tree nut or peanut allergy selected, SafeBelly answers "No, avoid this." for foods that contain that nut, and it never answers "Yes" for an allergen you have told it about.

Nuts contain GOS and fructans, the oligosaccharide FODMAPs. The amount varies a lot by type, which is why some nuts are a staple during the elimination phase and others are kept for the reintroduction phase.

The almond example comes from Monash’s list of foods that are low FODMAP at a smaller serving. Serving sizes for every nut are in the Monash FODMAP app, which is updated as foods are retested. Our guide to FODMAP portion sizes explains why a handful and a bag can get different answers.

• Nut butters: check for added honey, which Monash lists as high FODMAP. See high-FODMAP foods and swaps.
• Mixed nuts and trail mix: often include cashews and pistachios, plus dried fruit that may be high in fructose.
• Nut flours and bars: a bar made mostly of cashews or with added inulin is a different food from a few walnuts.

Peanuts grow underground and are legumes, related to beans and peas. Tree nuts grow on trees. FARE explains that the allergies are separate, but overlap is common: about 40 percent of children with a tree nut allergy are also allergic to peanut.

• One tree nut often means others. FARE reports that about 50 percent of children allergic to one tree nut are allergic to another, and that cashew and pistachio, and walnut and pecan, are closely linked.
• Tree nut allergy tends to be lifelong. FARE notes that about 9 percent of children with tree nut allergy eventually outgrow it.
• Peanut and other legumes. FARE says peanut allergy doesn’t mean you are more likely to be allergic to other legumes, with lupin as the exception to ask about. See our beans, lentils and chickpeas guide.
• Refined peanut oil. FARE notes that highly refined peanut oil is exempt from allergen labeling and that studies suggest most people with peanut allergy tolerate it, but cold-pressed, expelled or extruded peanut oils may contain peanut protein. Ask your allergist.

Which nuts you avoid is a decision for your allergist, who may recommend avoiding all nuts or testing specific ones. Don’t try a new nut on your own to see what happens.

In January 2025, the FDA published the fifth edition of its food allergen guidance. Its FAQ confirms that coconut is no longer on the FDA’s tree nut list, along with beech nut, butternut, chestnut, chinquapin, cola/kola nut, ginkgo nut, hickory nut, palm nut, pili nut, shea nut and lichee nut.

• Coconut must still be in the ingredient list. It just isn’t treated as a major allergen, so it shouldn’t appear in the "Contains" statement.
• One gap: the FDA notes that a natural coconut flavor may be listed simply as "natural flavor".
• Labels are in transition. The FDA says some packaged foods may still show coconut in a "Contains" statement for a few years.
• The 12 tree nuts still listed include almond, Brazil nut, cashew, hazelnut, macadamia, pecan, pine nut, pistachio and walnut varieties.

FARE notes that coconut has typically not been restricted for people with tree nut allergy, but that coconut allergy does exist. If you react to coconut, read the full ingredient list rather than relying on the "Contains" line, and ask your allergist about natural flavors.

In the UK and EU, the 14 allergens include "nuts", defined as almonds, hazelnuts, walnuts, cashews, pecans, Brazil nuts, pistachios and macadamia nuts, with peanuts listed separately.

With nut allergies, the nut you can see is often less of a worry than the one you can’t. FARE lists tree nut protein in cereals, crackers, cookies, candy, energy bars, flavored coffee, frozen desserts, marinades, barbecue sauces and some cold cuts, and peanut in chili, egg rolls, pesto, salad dressings, granola, ice cream and vegetarian meat substitutes.

• High-risk places: FARE names ice cream parlors, bakeries and coffee shops for tree nuts, and notes high cross-contact risk with peanut in many African, Asian and Mexican restaurant dishes.
• Seeds and seed butters: FARE notes sunflower seeds are often processed on shared equipment with peanuts. Sesame is its own major allergen in the US.
• "May contain" statements are voluntary in the US. The FDA says they are meant only for unavoidable cross-contact, so a missing warning isn’t a guarantee. Contact the manufacturer if you need to know.
• Beyond food: FARE notes nut oils can turn up in lotions, hair products and soaps, and nut flavoring in some alcoholic drinks.

If some nuts don’t suit your gut, the low-FODMAP options in Monash’s list (macadamias, walnuts, peanuts and most seeds) usually cover snacks, salads and baking. If you have a nut allergy, swaps depend on what your allergist has cleared: seeds such as pumpkin seeds are a common choice, but check for shared-equipment warnings and for sesame if that is also one of your allergens.

Talk to a doctor or allergist if you notice itching, hives, swelling or vomiting when you eat nuts, if you want to know whether you can eat other nuts, or if you wonder whether a childhood nut allergy has changed. Talk to a dietitian if nuts seem to cause digestive symptoms, so you can test them in a structured way rather than cutting them all out.