Brussels Sprouts: Nutrients, What Research Shows and Safety

Brussels sprouts are the small leafy buds of Brassica oleracea var. gemmifera, a plant in the cabbage family (Brassicaceae). People eat the buds, usually cooked, for their vitamins, fiber and plant compounds. This page keeps the food separate from supplements and from hype, and says what the research does and does not show.

Read this first

• If you take warfarin (a blood thinner), Brussels sprouts are high in vitamin K, which affects how the medicine works. Official advice is to keep your intake steady and tell your clinic before big changes, not to avoid vegetables on your own. [2][3][4]
• Allergy to this vegetable is not described in the sources we read, but any food can cause a reaction. For trouble breathing or swelling of the face or throat, call 911.
• Studies of people who eat more cruciferous vegetables (the cabbage family) link them with lower risks of some diseases, but that is association, not proof that the vegetables caused it. Trials in people are few. [9][5]
• Eating them with adequate iodine is not shown to harm the thyroid in a large 2024 review. [8]

What is in it (USDA values)

Source: USDA FoodData Central, SR Legacy item 170383, "Brussels sprouts, raw" [1]. USDA household portions: 1 cup = 88 g; 1 sprout = 19 g. % Daily Value uses the FDA 2016 Daily Values; values vary with variety, ripeness and storage. USDA also lists lutein plus zeaxanthin (1,590 µg per 100 g) and beta-carotene (450 µg per 100 g). [1]

The main plant compounds are glucosinolates, sulfur-containing compounds in the cabbage family. The Linus Pauling Institute lists about 104 mg of total glucosinolates in a half cup (44 g) of raw Brussels sprouts, the highest of the vegetables in its table, and says they can form compounds such as sulforaphane. [5] Most of what is known about what these compounds do comes from lab and animal work. Human evidence is limited (see below). [5]

What research says

Eaten as food vs taken as a supplement or extract. The human trials above that used isothiocyanate products tested concentrated compounds or extracts, not a plate of sprouts. [5] Those results do not carry over to the food, and the food's associations do not prove an extract works. See sulforaphane and glucosinolates.

How much is a normal serving

• The NHS counts 80 g of fresh, canned or frozen vegetables as one portion of its 5 A DAY advice (page last reviewed 9 June 2026). [12] That is a little under the USDA cup of raw sprouts (88 g). The WHO fact sheet (January 2026) says at least 400 g of fruit and vegetables a day for people older than 10. [13] These are official figures for information, not a prescription for you.
• Cooking. Cooking inactivates myrosinase, the plant enzyme that turns glucosinolates into sulforaphane-type compounds; light steaming for under 5 minutes keeps some of it, and gut bacteria do much of the conversion when sprouts are cooked. [5] A 2024 lab study of Brussels sprouts compared cooking methods and found sous-vide cooking led to larger glucosinolate losses than conventional cooking, while isothiocyanates and indoles showed no notable change. [7] A review of heat processing says boiling, steaming and microwaving change vitamin C levels depending on temperature and time (the abstract gives no figures). [10] We did not find a source giving a reliable percentage of vitamin C lost from Brussels sprouts by method: Proper evidence not found (searched Europe PMC). See fresh, frozen and canned produce.

Safety, allergy and medicines

• Warfarin and other vitamin K antagonists. USDA lists 177 µg of vitamin K per 100 g. [1] MedlinePlus says vitamin K affects how warfarin works, that intake should be steady from day to day and that sudden changes can alter the medicine's effect. [2] The NHS says foods high in vitamin K can affect warfarin, that you can still eat them, and to ask your warfarin clinic; it also says not to take vitamin K supplements without advice (page reviewed 24 February 2026). [3] A hospital patient guide lists Brussels sprouts among vitamin K-rich foods and advises consistency. [4]
• Thyroid. Some breakdown products of glucosinolates are suspected of reducing thyroid hormone production, which is why raw crucifers are called goitrogenic. The 2024 systematic review found most evidence does not support this in people with adequate iodine. [8] If you have a thyroid condition, ask your clinician before changing what you eat. See thyroid conditions and iodine.
• Gas and bloating. In a 2025 UK survey of 516 adults, 23% said they perceived Brussels sprouts as causing flatulence; the paper noted this worried few respondents. [11] This is self-reported perception, not a measured effect. The sources we read gave no sourced fix; see foods for gut health and bloating. We did not read a FODMAP source for sprouts: Proper evidence not found.
• Bitter taste. An unreviewed 2026 preprint (a study not yet checked by other scientists) reported that people with bitter-sensitive versions of the TAS2R38 gene said they liked Brussels sprouts less. [14] Treat this as early, not established.
• Allergy. No source we read describes allergy patterns for Brussels sprouts specifically: Proper evidence not found.
• Pregnancy. No special caution for the vegetable as food appeared in the sources we read; see foods in pregnancy.

Choosing, storing and food safety

• Choose produce that is not bruised or damaged; refrigerate cut or packaged produce at 40 °F or below. [15]
• Rinse under running water. The FDA says not to use soap, detergent or produce wash. Washing reduces but does not eliminate bacteria; cooking thoroughly kills harmful bacteria. [15]
• Keep produce away from raw meat, poultry and seafood and their utensils. [15]

Related pages

• Cruciferous vegetables
• Sulforaphane and glucosinolates in cruciferous vegetables
• Foods and medicine interactions: vitamin K, grapefruit and others
• Fresh, frozen and canned produce
• Foods for gut health and bloating
• Leafy greens