Mustard Greens: Nutrition, Benefits, Cooking and Cautions

Mustard greens are the peppery, frilly or flat leaves of the mustard plant, Brassica juncea, eaten raw in salads, cooked like collards or pickled in many Asian cuisines. They are very low in calories and rich in vitamins: a cup of raw chopped mustard greens has about 15 calories and 44% of the Daily Value for vitamin C, and a cup cooked supplies about 96% of the Daily Value for vitamin A and nearly seven times the Daily Value for vitamin K, according to USDA data. Below are the USDA mustard greens nutrition facts, how they compare with other greens, what is known about mustard greens benefits, notes for people on warfarin, and how to cook mustard greens to tame their bite.

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

What are mustard greens?

Mustard greens come from Brassica juncea, the same species whose seeds are used for some brown mustards. A 2026 review in Frontiers in Microbiology describes the plant as rich in vitamins, minerals and glucosinolates. As a member of the Brassica genus, it belongs to the cruciferous family that the National Cancer Institute describes, along with collards, kale, cabbage, arugula and watercress. NCI explains that glucosinolates give these vegetables their pungent aroma and bitter flavor, and mustard greens are among the sharpest tasting of the group. Varieties range from curly green leaves to red-tinged and flat Asian types. For how they fit among other greens, see our guide to green vegetables.

Mustard greens nutrition: raw, cooked and frozen

The table uses USDA FoodData Central SR Legacy entries for raw mustard greens (FDC 169256), mustard greens boiled and drained without salt (FDC 169257) and frozen mustard greens boiled without salt (FDC 169259), at USDA’s portion weight for one cup chopped. The percent Daily Value (%DV) uses FDA Daily Values.

Raw mustard greens stand out for vitamin C: per 100 grams, USDA lists 70 milligrams, about twice the value for raw collards and somewhat less than raw kale. Cooking shrinks the leaves, so a cup of cooked greens holds far more vitamin A and K, while vitamin C per 100 grams drops. Mustard greens are also a source of the carotenoid lutein; the Linus Pauling Institute ranks cooked mustard greens near the top for lutein per cup, a topic in our lutein guide. Our guides to vitamin C foods and beta-carotene put these numbers in context.

Mustard greens vs collards, kale and spinach

This table compares one cup of each raw green, chopped, using USDA SR Legacy portion weights. A raw cup weighs very different amounts depending on the leaf, so the per-cup values partly reflect how tightly the leaves pack.

Per cup, raw mustard greens supply about twice the vitamin C of raw kale and three times that of raw collards in USDA data. Cooked, collards carry more fiber and calcium per cup, while mustard greens carry slightly more vitamin K. Our sibling guide to collard greens has the full cooked comparison, and our kale guide covers kale raw and cooked. For iron from plant foods and why vitamin C matters for it, see our guide to iron in foods.

Mustard greens benefits: what the evidence says

There are almost no human trials of mustard greens as a vegetable. The realistic case for mustard greens benefits rests on USDA nutrient data: vitamins C, A, K and E, some fiber and calcium, and carotenoids, all for very few calories. Research on Brassica vegetables has focused on glucosinolates and the compounds they form when leaves are chopped or chewed. The National Cancer Institute says those compounds show effects in lab and animal studies, but studies in people have shown mixed results. Claims that mustard greens flush toxins or protect against disease are not supported.

Calcium deserves a note. Mustard greens list a modest amount of calcium, about 13% of the Daily Value per cooked cup in USDA data. The NIH Office of Dietary Supplements names spinach and collard greens as high in oxalic acid, which lowers calcium absorption, but does not name mustard greens either way. Our guides to calcium in foods and oxalates cover the details.

Vitamin K, warfarin and mustard greens

A cup of cooked mustard greens lists more vitamin K than a cup of cooked collards in USDA data. For people who take warfarin (Coumadin), the NIH Office of Dietary Supplements says vitamin K intake from food and supplements should stay consistent, because sudden changes can raise or lower the drug’s effect. MedlinePlus advises eating consistent amounts of vitamin K foods week to week and talking to your doctor before changing your diet. That means greens can stay on the menu; the concern is big swings. Our guide to vitamin K in foods lists other sources.

How to cook mustard greens

• Rinse and trim: CDC advises rinsing produce under running water. Swish the leaves to remove grit and cut off thick stems.
• Raw: young, tender leaves add a peppery bite to salads, much like arugula. Mixing them with milder lettuces softens the heat.
• Cooked: sauteing, simmering or braising mellows the sharp flavor. Mustard greens cook faster than collards, so they are often added later when the two share a pot.
• Add some fat: NIH notes that eating vegetables with some fat improves vitamin K absorption, and carotenoids are absorbed with fat too.
• Salt: in USDA data, mustard greens boiled in salted water list about 252 milligrams of sodium per 100 grams vs 9 without salt. Our low sodium foods guide has flavor ideas.

Pickled and fermented mustard greens

Fermented mustard products are traditional across East and Southeast Asia. The 2026 Frontiers in Microbiology review explains that lactic acid bacteria drive the fermentation and that salt concentration is a key processing step. The same review notes that compounds such as biogenic amines and nitrite can form during fermentation and are controlled through careful processing. Store-bought pickled mustard greens can be high in sodium, so the Nutrition Facts label is the place to check. Our guides to fermented foods and sauerkraut cover what fermentation does and does not change.

Are mustard greens healthy for everyone? Cautions

• Thyroid: NIH lists cruciferous vegetables among foods with goitrogens, which interfere with iodine uptake, but says reasonable amounts are not a concern for most people in the US with adequate iodine. See our iodine guide.
• Digestion: NIDDK lists cruciferous vegetables among foods that can cause gas. Our gas and bloating guide has tips.
• Allergy: mustard greens are not one of the nine major food allergens under US law, but any food can cause a reaction. Swelling or breathing trouble needs urgent care; for unclear symptoms, see an allergist.
• Medicines: beyond warfarin, ask your clinician or pharmacist if you have questions about diet and a prescription.

Frequently Asked Questions

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Last reviewed October 2026.

Related guides: Collard Greens: Nutrition, Benefits, Cooking and Safety Notes, Leafy Greens: USDA List of Dark Greens, Spinach vs Kale and Tips, Kale Benefits: USDA Kale Nutrition, Raw vs Cooked and Safety Notes.