Yes, radishes are low FODMAP. Monash University, the research group that developed and maintains the FODMAP database, lists radishes as low FODMAP at a standard vegetable serving of 75 grams (about 2.65 ounces). Some NHS guidelines go further, listing radishes among vegetables with no upper FODMAP limit at all, meaning you can eat larger portions without triggering FODMAP-related symptoms.
Serving Sizes and Safe Amounts
A standard low FODMAP serving of radish is 75 grams, which works out to roughly five or six medium red radishes. At this portion, radishes test green (safe) on the Monash traffic light system. The Gloucestershire Hospitals NHS Foundation Trust lists radishes among vegetables where “there is no upper limit to the amount you can have at once,” suggesting they remain very low in fermentable sugars even in generous portions.
For context, 75 grams of sliced radish is about half a cup. Most people use radishes as a garnish, in salads, or sliced into a snack plate, so staying within a safe range happens naturally without much measuring.
Daikon and Other Varieties
Daikon radish (the large white variety common in East Asian cooking) is also considered low FODMAP. If you enjoy Korean-style dishes, stir-fries, or soups that call for daikon, these are generally safe choices during the elimination phase of a low FODMAP diet. The same 75-gram starting point applies as a baseline, though you can test your tolerance from there.
Why Radishes Can Still Cause Gas
Being low FODMAP does not automatically mean a food is gentle on every sensitive stomach. Radishes are cruciferous vegetables, and like their relatives (broccoli, cabbage, cauliflower), they contain sulfur compounds that can produce gas during digestion. Some IBS dietary guides specifically flag radishes as a vegetable that “may not be digested well by your body and can cause gas and bloating,” even though the issue is not FODMAP-related.
The distinction matters. FODMAPs are specific short-chain carbohydrates that ferment rapidly in the large intestine. Radishes are low in those. But the sulfur compounds and the peppery isothiocyanates that give radishes their bite can irritate some people independently. If you find radishes bother you despite being low FODMAP, this is likely why. Cooking radishes (roasting, sautéing, or adding them to soups) softens both the flavor and some of these compounds, which can improve tolerance.
Watch Out for Pickled Radishes
Plain raw or cooked radishes are straightforward, but pickled radishes need a closer look. Monash University’s research on fermented and pickled foods shows that fermentation can change a food’s FODMAP content. Pickled mixed vegetables, for instance, test high in FODMAPs even when the raw ingredients started low. Small cucumbers stay low FODMAP after pickling as gherkins, but the outcome depends on the specific food.
Commercial pickled radishes (like the bright pink variety served with Korean fried chicken or the Japanese pickled daikon called takuan) often contain added sugar, garlic, or onion in the brine. Garlic and onion are among the highest FODMAP ingredients in any kitchen, so even a small amount in a marinade can make an otherwise safe food problematic. If you want pickled radishes on a low FODMAP diet, check the ingredient list carefully or make your own with a simple vinegar brine, sugar (regular white sugar is low FODMAP), and salt.
Nutritional Profile
Radishes are low in calories but carry some useful nutrients. Half a cup of sliced raw radishes provides about 14 percent of your daily vitamin C needs and 1 gram of fiber. That fiber count is modest, which is actually part of why radishes sit comfortably in the low FODMAP category: they simply don’t contain much fermentable material.
As cruciferous vegetables, radishes also contain compounds called isothiocyanates, which form when you chew or cut the vegetable. These compounds have been studied for their potential to support the body’s detoxification processes and may help protect gastric tissue. One study found that radish juice helped strengthen the stomach’s mucosal barrier, the protective lining that prevents ulcers. For people with IBS who are already dealing with a sensitive gut, that’s a welcome bonus from a crunchy, easy-to-prepare vegetable.
Easy Ways to Add Radishes to a Low FODMAP Diet
- Raw in salads: Thinly sliced radishes add crunch and a peppery bite to any green salad. Pair with a low FODMAP dressing (olive oil and lemon juice works well).
- Roasted: Halve radishes, toss with olive oil and salt, and roast at 400°F for about 20 minutes. Roasting mellows their sharpness into something almost sweet and buttery.
- As a snack: Whole radishes with a pinch of sea salt or a low FODMAP dip make a satisfying, no-prep snack.
- In soups and stir-fries: Daikon radish holds up well in broth-based soups and stir-fries, absorbing flavor while staying tender.