Radicchio: Nutrition, Bitter Taste and Vitamin K Notes

Radicchio is a crisp, wine-red leafy vegetable with white veins and a bold, bitter bite, most familiar from Italian cooking. What is radicchio, botanically? It is a form of chicory, Cichorium intybus, the same species as Belgian endive and the root chicory grown for inulin. In USDA data, one cup of shredded raw radicchio has about 9 calories and 85% of the Daily Value for vitamin K, along with copper and vitamin E. That vitamin K is the one practical caution: people who take warfarin need a steady intake. This guide covers radicchio nutrition, where the bitterness comes from, how to cook it, and what research does and does not show.

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

What is radicchio?

Chicory belongs to the Asteraceae, the daisy family, and is grown in three main cultivated groups: root chicory, leaf chicory and witloof, according to a 2023 paper in Frontiers in Plant Science. Radicchio is one of the leaf chicory subgroups, alongside Sugarloaf and Catalogne. A 2021 study in Plant Biotechnology Journal notes that the same species is eaten as Belgian endive (witloof) in northern Europe and as radicchio in Italy, while industrial root chicory is grown for the fiber inulin.

The names get confusing. Belgian endive is a chicory, but curly endive and escarole belong to a related species, Cichorium endivia. Radicchio is also often mistaken for red cabbage because the round heads look alike on the shelf. Cut one open and the difference is clear: radicchio leaves are thinner, more tender and much more bitter.

In US stores the most common type is Chioggia, a round, tight head about the size of a softball. Treviso is longer, with narrow, tapered leaves, and specialty markets sometimes carry speckled or loose-leaf types. All of them can be eaten raw or cooked.

Radicchio nutrition facts (USDA)

The values below come from USDA FoodData Central, SR Legacy: Radicchio, raw (168564), Arugula, raw (169387), Endive, raw (168412) and Chicory, witloof, raw (170404). Percent Daily Values use the FDA Daily Values. In USDA portion data, one cup of shredded radicchio weighs 40 grams and one leaf about 8 grams.

Vitamin K is the standout. Gram for gram, raw radicchio lists more than twice the vitamin K of raw arugula in USDA data, and a single cup covers most of the Daily Value. Radicchio also has more copper and vitamin E than the other greens in the table. It is light on fiber, though: 100 grams has 0.9 grams, about a third of what curly endive or Belgian endive provide. Protein is low too, at 1.43 grams per 100 grams.

For context, our vitamin K foods guide shows where radicchio sits among other greens, and the arugula guide covers the peppery green it is often paired with in salads. Our guide to greens compares many more options, and the high-fiber foods list is the better place to look if fiber is your goal. SR Legacy has no entry for grilled or cooked radicchio, so these numbers describe raw leaves.

Why radicchio tastes bitter

The bitterness comes from plant compounds called sesquiterpene lactones. A 2015 study in Food Research International described them as the main determinants of radicchio bitterness and found eight of them in four chicory varieties, including lactucin and lactucopicrin. Lactucopicrin was the most abundant. Levels differed widely between varieties: the early Treviso type had the highest total and the late Treviso type the lowest. The 2023 Frontiers paper lists lactucin, 8-deoxylactucin and lactucopicrin as the principal bitter compounds across Cichorium plants.

Bitterness is a big deal for growers. The 2021 Plant Biotechnology Journal study used gene editing to nearly switch off these compounds in root chicory, where they have to be removed during inulin extraction. In the kitchen, cooks tame the bite in simple ways:

• Slice the leaves thinly and toss them with milder greens.
• Grill or roast wedges until the edges brown; heat brings out sweetness.
• Pair the leaves with something sweet, salty or rich, such as pears, oranges, honey, nuts, aged cheese or a balsamic dressing.
• Many cooks soak cut leaves in cold water for a short time to soften the edge before dressing them.

The red color and other plant compounds

A 2015 study in the Journal of Food Composition and Analysis analyzed 64 chicory samples for phenolic compounds, a group that included the red anthocyanin pigments. Red head radicchio types had the highest phenolic content of all the chicory types tested, with wide variation from one sample to another.

Containing a compound is not the same as delivering it to the body. In a small 2020 trial in Nutrients, 16 healthy volunteers drank witloof chicory juice, and the researchers found the bitter sesquiterpene lactones were poorly absorbed, with much of them broken down by gut bacteria. Lab results on chicory extracts therefore say little about what a radicchio salad does.

Radicchio and warfarin: steady intake matters

Because one cup of shredded radicchio supplies about 85% of the Daily Value for vitamin K, it matters for anyone who takes warfarin (Coumadin). The NIH Office of Dietary Supplements fact sheet calls the warfarin and vitamin K interaction serious and potentially dangerous, and says people taking warfarin need a consistent intake from food and supplements, because sudden changes can raise or lower the drug’s effect. MedlinePlus gives similar advice: keep vitamin K foods consistent, avoid large amounts of leafy green vegetables, and talk to your doctor before changing your diet.

• The goal is consistency, not avoidance. A clinician can match the medication to a steady eating pattern.
• Big swings, such as a sudden run of large radicchio salads after weeks without greens, are what to avoid.
• Newer blood thinners work differently; ask your pharmacist whether vitamin K matters for yours.

Vitamin K is fat-soluble, and the ODS fact sheet notes that eating vegetables with some fat improves absorption, which is one reason an olive-oil dressing suits radicchio well.

How to choose, store and cook radicchio

1. Choose: look for firm, heavy heads with glossy, crisp leaves and no brown or slimy patches. A little browning on the cut stem end is normal.
2. Store: keep the head whole, wrapped loosely, in the crisper drawer, and cut it only when you are ready to cook it.
3. Prep: pull off any wilted outer leaves, rinse, then halve or quarter the head. Keep the core attached if you plan to grill wedges so they hold together.
4. Raw: shred it into slaws and salads, or separate whole leaves into cups for fillings.
5. Cooked: grill or roast wedges with olive oil and salt, stir shredded leaves into risotto or pasta near the end, or braise them briefly. Cooking turns the color from red to a darker, brownish purple.

Radicchio sits well beside other members of the produce aisle we cover: cabbage for slaws, kale for sturdy salads, and arugula for peppery contrast. For a very different vegetable that must be cooked before eating, see our sibling guide to bamboo shoots.

Is radicchio healthy? What the evidence says

Radicchio is a very low-calorie vegetable that adds vitamin K, copper and vitamin E, and it can fit a varied diet like other greens. Claims beyond that are not well supported. Most research on chicory compounds is laboratory chemistry or plant breeding, and the one human study above looked at absorption, not health outcomes.

One point that often gets mixed up: the inulin sold as a fiber ingredient comes from industrial root chicory, a different cultivated form, not from radicchio leaves, which are low in fiber in USDA data. Our inulin guide covers that ingredient.

Frequently Asked Questions

Questions about a label? Contact us or read our Buyer’s Guide. Food comes first; follow the label and ask a healthcare provider before starting a supplement, especially if you take medicines, are pregnant or have a food allergy. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Last reviewed October 2026.

Related guides: Bamboo Shoots: Nutrition, Safety and Canned vs Fresh, Arugula: Nutrition, Benefits and How It Compares to Spinach, Endive: Belgian Endive vs Curly Endive and Endive Nutrition.