Cashews are not low FODMAP. Monash University, the leading authority on FODMAP testing, classifies cashews as a high FODMAP food. The specific fermentable carbohydrates in cashews are fructans and galacto-oligosaccharides (GOS), two types of short-chain carbohydrates that can trigger bloating, gas, and abdominal pain in people with IBS.
Why Cashews Are High FODMAP
Most nuts are relatively gut-friendly, but cashews are one of the exceptions. They contain significant amounts of two FODMAP types: fructans and GOS. These are chains of sugar molecules that your small intestine can’t fully break down. Instead, they pass into the large intestine, where gut bacteria ferment them and produce gas. They also draw extra water into the bowel, which can cause loose stools or cramping in sensitive individuals.
Cashews and pistachios are the only two nuts that Monash University flags as high FODMAP. This means there’s no established “safe” small serving of regular cashews during the elimination phase of a low FODMAP diet. Unlike some foods that shift from low to high FODMAP depending on portion size, cashews hit the threshold quickly enough that they’re categorized as high across the board.
The Activated Cashew Workaround
There is one exception worth knowing about. Activated cashews, which are soaked in water and then dried, test as low FODMAP at a serving of about 10 nuts (15 grams). Monash University has confirmed this through lab testing. The soaking process allows some of the water-soluble FODMAPs to leach out, reducing fructan and GOS levels enough to bring a small serving into the safe range.
You can buy activated cashews at health food stores or make them at home by soaking raw cashews in water for several hours, then dehydrating them in an oven at a low temperature until they’re completely dry and crisp again. The texture is slightly softer and the flavor a bit sweeter than regular roasted cashews. If you love cashews and don’t want to give them up entirely, this is worth trying during the reintroduction phase, starting with a small portion to gauge your tolerance.
Cashew Milk, Butter, and Other Products
Cashew-based products like cashew milk, cashew butter, and cashew cheese are a gray area. Because they’re made from whole cashews, they carry the same fructan and GOS content, diluted to varying degrees depending on the product. Cashew milk, for example, typically uses a relatively small amount of cashews blended with a lot of water, so the FODMAP load per serving may be lower than eating a handful of whole nuts. But without specific lab testing on a particular brand, it’s hard to know where the line falls.
During the strict elimination phase, most dietitians recommend avoiding cashew-based products entirely. During reintroduction, you can test small amounts and see how your body responds.
Low FODMAP Nuts to Use Instead
If you’re looking for a nut to snack on or cook with during the elimination phase, several options test well at standard serving sizes:
- Macadamia nuts are one of the lowest FODMAP nuts available and work well as a rich, buttery substitute in both cooking and snacking.
- Peanuts (technically a legume) are low FODMAP in moderate portions. Plain or unsalted varieties are the safest bet.
- Walnuts are generally well tolerated and add a similar crunch to salads and baked goods.
- Almond butter is often acceptable in measured amounts, though whole almonds become higher FODMAP at larger servings (roughly above 10 nuts).
- Pumpkin and sunflower seeds are low FODMAP options that work as toppings or in trail mixes.
Portion control still matters with all of these. FODMAP content is dose-dependent, and eating a very large amount of any nut can push the total fermentable carbohydrate load high enough to cause symptoms. A serving of around 20 to 30 grams (a small handful) is a reasonable starting point.
Cooking Without Cashews
Cashews play a specific role in many recipes, particularly in vegan cooking, where they’re blended into creamy sauces, soups, and dairy-free cheeses. Macadamia nuts are the closest low FODMAP substitute for this purpose. They blend into a similarly smooth, rich cream and have a mild enough flavor to work in savory dishes. Sunflower seeds soaked and blended can also mimic cashew cream in a pinch, though the flavor leans slightly more earthy.
For recipes where cashews are used for crunch (stir-fries, grain bowls, salads), peanuts or walnuts are easy swaps. They won’t taste identical, but they fill the same textural role without the FODMAP load. If you’re following a recipe from a non-FODMAP cookbook that calls for cashews, substituting one of these alternatives is usually the simplest adjustment you can make.