Radish Benefits: USDA Nutrition, Daikon Radish and Sprouts

Radish benefits start with what USDA data show: radishes are crisp, watery root vegetables with very few calories, a little fiber and a useful amount of vitamin C for something so light. A cup of sliced red radishes has about 19 calories, and daikon radish, the long white radish common in Japanese, Korean and Chinese cooking, is just as light. Radishes belong to the mustard family, so they carry the same kind of peppery sulfur compounds as cabbage and mustard greens. This guide walks through radish nutrition for red radishes, daikon and radish sprouts, what the small amount of human research actually tested, and the food safety point about raw sprouts that most roundups skip.

Peptide Labs does not sell radishes or radish products. This article is general nutrition information, not medical advice.

What is a radish?

Radishes are the roots of Raphanus sativus, a member of the Brassicaceae (mustard or cruciferous) family alongside cabbage, broccoli, turnips and horseradish. Several kinds show up in US stores:

• Red radishes: the small round radishes with red skin and white flesh, eaten raw in salads and on snack plates.
• Daikon radish: a long, white radish with a milder, juicier bite. It is eaten raw, simmered in soups and stews, grated as a garnish, and pickled; it is a common ingredient in kimchi.
• White icicle radishes: slender white radishes, sharper than daikon.
• Watermelon and black radishes: specialty radishes with green-and-pink or dark skin; USDA SR Legacy does not list them separately.
• Radish sprouts and microgreens: young seedlings with a strong peppery taste.

Radish nutrition: USDA values per cup

The table shows USDA SR Legacy values for one cup of sliced raw radish, about 116 grams, with the percent of the FDA Daily Value where one exists.

Radishes are about 95% water by weight in USDA data, which is why the calorie count is so low. One medium red radish has less than 1 calorie. They are also low in carbohydrate, so radishes often appear on our list of low-carb foods as a crunchy swap for chips or crackers. For vitamin C, radishes are a modest source; our guide to vitamin C foods shows produce with much more per serving. Radishes have some potassium, but far less per serving than the items in our potassium foods guide.

Daikon, icicle, cooked and sprouted radish per 100 grams

Boiling daikon lowers its vitamin C and folate in these USDA entries, as it does for many vegetables, because both nutrients are sensitive to heat and leach into cooking water. Radish sprouts are denser in folate and protein per 100 grams, but a cup of sprouts weighs only about 38 grams.

Radish benefits: what the research shows

Most radish research is lab chemistry, plant breeding and animal work. Human trials of radish as a food are rare and small, so the honest summary is short.

• Nutrient profile: the clearest radish benefits are the ones in the USDA table: very few calories, some fiber, vitamin C and potassium, and a lot of water and crunch.
• Sakurajima radish trial (2026, Nutrients): an open-label randomized crossover trial gave 21 adults with metabolic syndrome 14 days each of a giant Sakurajima radish powder, a regular radish powder and their usual diet. The radish powder did not improve the main outcome, a measure of blood vessel function called flow-mediated dilation, compared with usual diet or the other radish.
• Composition studies: a 2023 study of 16 radish varieties grown in three cycles found that growing conditions changed the levels of taste-related and plant compounds more than the variety did. The same radish can be milder or sharper depending on season and soil.
• Lab and animal work: radish extracts and isothiocyanates are studied for antioxidant and other activity in cells and animals. Those results do not show what eating radishes does in people.

Why radishes taste peppery

Radishes store sulfur compounds called glucosinolates. When you slice, grate or chew a radish, an enzyme called myrosinase breaks them down into isothiocyanates, the compounds behind the sharp, peppery bite. In radish the main one studied is glucoraphasatin, which breaks down into a compound called raphasatin. A 2022 study of small Korean radishes used for kimchi found that this compound alone did not explain why spring radishes taste hotter than autumn ones; sugar levels mattered too. Grated daikon is sharpest right after grating, and cooking tames the bite.

Pickled and fermented radish, such as kimchi and Japanese pickles, keep the crunch but often add a lot of salt; our guides to fermented foods and sauerkraut explain what fermentation changes and why the sodium line on the label matters.

Radish safety: sprouts, thyroid and digestion

• Raw radish sprouts: in July 1996, white radish sprouts from a single farm were the only uncooked food common to the school lunches linked to a massive E. coli O157:H7 outbreak among schoolchildren in Sakai City, Japan. A 1998 lab study found the bacteria inside the tissues of radish sprouts grown from contaminated seed, where rinsing cannot reach, and its authors stressed clean seed or heating sprouts before eating. Young children, older adults, pregnant people and anyone with a weakened immune system should ask a clinician about raw sprouts of any kind.
• Thyroid: like other cruciferous vegetables, radishes contain compounds that can interfere with how the thyroid uses iodine. The NIH Office of Dietary Supplements notes that most such goitrogens matter only when iodine intake is also low. Our iodine guide covers iodine sources; if you have a thyroid condition, ask your clinician about your diet.
• Gas and bloating: raw cruciferous vegetables can cause gas in some people. If you follow a low-FODMAP plan for IBS, our low-FODMAP guide explains how a dietitian helps you test portions.
• Allergy: radish is not one of the nine major food allergens that US labels must declare, but any food can cause a reaction. Hives, swelling or trouble breathing needs urgent care.

Radish has a pungent cousin with a much stronger bite; our sibling guide to horseradish explains its nutrition and how it differs from the green paste served with sushi.

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Last reviewed October 2026.

Related guides: Horseradish: Nutrition, Heat, Prepared Horseradish and Wasabi, Low Calorie Snacks: USDA Calories per Serving and 100-Calorie Portions, Turnip: Nutrition, Turnip Greens, Benefits and Cautions.