The Quick Numbers

Let’s start with what most people want to know: how much is in a serving.

One Cup Raw Brussels Sprouts (88g)

• Calories: 38
• Protein: 3g
• Carbohydrates: 8g
• Fiber: 3.3g
• Fat: 0.3g
• Sugar: 2g

One Cup Cooked Brussels Sprouts (156g, boiled and drained)

• Calories: 56
• Protein: 4g
• Carbohydrates: 11g
• Fiber: 4.1g
• Fat: 0.8g
• Sugar: 2.7g

For a vegetable, these numbers are remarkable. Four grams of protein per cooked cup is legitimately high — most vegetables hover around 1 to 2 grams. The fiber content is excellent too. A single cooked cup delivers about 16% of your daily fiber needs.

And 56 calories for a cup of cooked vegetables that taste this good when roasted? That’s almost unfair.

Vitamins: Where Brussels Sprouts Dominate

This is where things get impressive. Brussels sprouts aren’t just “pretty good” for vitamins — they’re elite.

Vitamin K

One cooked cup provides about 270% of the daily recommended value of vitamin K1.

That’s not a typo. A single serving gives you nearly three days’ worth of vitamin K. This vitamin is essential for blood clotting and bone health. It helps direct calcium into bones and teeth instead of letting it accumulate in arteries.

Brussels sprouts are one of the highest vitamin K sources in the entire food supply. Kale edges them out, but not by much.

Vitamin C

One cooked cup delivers roughly 107% of the daily value of vitamin C — even after cooking, which destroys some of it. Raw Brussels sprouts contain even more.

Most people associate vitamin C with citrus fruits. But Brussels sprouts, gram for gram, contain more vitamin C than oranges. An orange has about 53mg of vitamin C. A cup of raw Brussels sprouts has about 75mg.

Vitamin C is an antioxidant that supports immune function, skin health, and iron absorption. Getting it from vegetables instead of supplements means you’re also getting fiber, other vitamins, and phytonutrients that a pill can’t replicate.

Other Vitamins

A cooked cup also delivers about 12% daily vitamin A (as beta-carotene), 15% daily folate (B9, critical for cell division and pregnancy), and meaningful amounts of B6 (14% DV) and thiamine (11% DV). Not standout amounts individually, but solid contributions across the board.

Minerals

Not mineral powerhouses on the level of spinach, but solid contributors: manganese (18% DV), potassium (11% DV), iron (10% DV — and the high vitamin C content boosts absorption of this plant-based iron), phosphorus (7% DV), and magnesium (6% DV).

Fiber: The Underrated Star

4.1 grams of fiber per cooked cup. That’s a big deal.

Most adults eat about 15 grams of fiber per day. The recommendation is 25 to 38 grams. So a cup of Brussels sprouts closes that gap meaningfully — delivering about 16% of your daily needs in a single side dish.

The fiber in Brussels sprouts is a mix of soluble and insoluble types. Soluble fiber feeds beneficial gut bacteria and helps regulate blood sugar. Insoluble fiber adds bulk and keeps things moving through the digestive tract.

This fiber content is also why Brussels sprouts are filling for so few calories. High-fiber foods take longer to chew, slow stomach emptying, and promote satiety. You feel full after eating a cup of roasted sprouts in a way that 56 calories of, say, crackers would never achieve.

Cancer-Fighting Compounds

This is where Brussels sprouts step into the big leagues, even among vegetables.

Glucosinolates

All cruciferous vegetables (broccoli, cauliflower, cabbage, kale) contain glucosinolates — sulfur-containing compounds that break down during digestion into biologically active molecules called isothiocyanates and indoles.

Brussels sprouts are particularly rich in specific glucosinolates, including sinigrin and glucobrassicin. (Interestingly, modern varieties were bred to contain less sinigrin — improving taste at the cost of some of these compounds.) Research has linked these compounds to:

• Reduced oxidative stress. Isothiocyanates activate the body’s own antioxidant defense enzymes, which may help protect cells from DNA damage.
• Anti-inflammatory effects. Chronic inflammation is a driver of many diseases, and glucosinolate byproducts appear to modulate inflammatory pathways.
• Potential cancer risk reduction. Multiple observational studies have associated higher cruciferous vegetable intake with lower rates of certain cancers, particularly colorectal, lung, and prostate cancers. The evidence is strongest for colorectal cancer.

Important caveat: observational studies show associations, not proof of causation. People who eat more cruciferous vegetables might also have other healthy habits. But the mechanistic evidence — how these compounds interact with cells in lab settings — supports a plausible biological pathway. The research is promising, not conclusive.

Kaempferol

Brussels sprouts are a notable source of kaempferol, a flavonoid antioxidant found in relatively few common foods. Research on kaempferol suggests anti-inflammatory and heart-protective properties, though most of this research is in cell studies and animal models. Human data is limited but encouraging.

Sulforaphane

When sprouts are chopped or chewed, an enzyme converts glucoraphanin into sulforaphane — studied extensively for potential protective effects against cancer and cardiovascular disease. To maximize it: chop sprouts and let them sit a few minutes before cooking. Cooking deactivates the enzyme, so giving it a head start helps.

Protein: High for a Vegetable

At 3 to 4 grams per cup, Brussels sprouts beat most vegetables — broccoli (2.5g), green beans (1.8g), carrots (1.2g), zucchini (1.5g). They won’t replace chicken breast, but for plant-based eaters building protein across the day, they make a meaningful contribution alongside grains and legumes.

Who Should Be Careful

People on Blood Thinners

If you take warfarin (Coumadin) or similar vitamin K-dependent blood thinners, the very high vitamin K content in Brussels sprouts is something to manage carefully.

Vitamin K promotes blood clotting — which is the opposite of what warfarin does. This doesn’t mean you can’t eat Brussels sprouts, but you need to keep your intake consistent. The problem isn’t eating them; it’s eating a lot one week and none the next. Fluctuating vitamin K intake makes it harder for your doctor to calibrate your warfarin dosage.

Talk to your doctor. They’ll likely tell you to eat a consistent amount rather than avoiding them entirely. Vitamin K is an essential nutrient — you still need it.

Digestive Sensitivity

Brussels sprouts contain raffinose, a complex sugar that the human small intestine can’t fully break down. Gut bacteria in the large intestine ferment it, producing gas. This is why Brussels sprouts cause bloating and flatulence in some people.

The effect varies widely between individuals. Some people eat Brussels sprouts with zero issues. Others feel like a balloon after half a cup.

If you’re in the second camp: start small. A quarter cup. Let your gut bacteria adapt over a few weeks of regular consumption — they do adapt, and the bloating typically decreases over time. Cooking sprouts thoroughly (rather than eating them raw) also reduces raffinose content and makes them easier to digest.

Thyroid Concerns

Cruciferous vegetables contain goitrogens that can interfere with thyroid hormone production in very high amounts. For people with healthy thyroid function, this is irrelevant at normal intake. For those with hypothyroidism, “very high amounts” means multiple cups daily, raw. Cooking reduces goitrogen content significantly.

Compared to Other Cruciferous Vegetables

How do Brussels sprouts stack up against their cousins?

Per 1 cup cooked	Calories	Protein	Fiber	Vitamin C	Vitamin K
Brussels sprouts	56	4g	4.1g	107% DV	270% DV
Broccoli	55	3.7g	5.1g	135% DV	245% DV
Cauliflower	29	2.3g	2.9g	55% DV	17% DV
Kale	43	3.5g	2.6g	89% DV	1180% DV
Cabbage	34	1.9g	2.8g	50% DV	91% DV

Brussels sprouts and broccoli are remarkably similar nutritionally — they’re essentially tied across most categories. Brussels sprouts edge out broccoli on protein and vitamin K. Broccoli wins on fiber and vitamin C. For a deeper dive into how Brussels sprouts compare to broccoli, see our full side-by-side breakdown.

Kale dominates on vitamin K (that number is real — kale is absurd), but Brussels sprouts hold their own on protein and fiber.

Cauliflower and cabbage are lower in nearly every category. They’re fine vegetables, but nutritionally they don’t compete with Brussels sprouts.

The Takeaway

Brussels sprouts are one of the most nutrient-dense vegetables available at any grocery store. High in protein and fiber for a vegetable, exceptional in vitamins C and K, loaded with antioxidants and cancer-fighting compounds, and all for 56 calories a cup.

The only people who need to manage their intake are those on blood thinners — and even then, the answer is consistency, not avoidance.

For a broader look at buying, storing, and cooking them, check out our complete guide to Brussels sprouts.

For a comparison with another low-carb brassica, check out kohlrabi nutrition — it leads the family on fiber and potassium.

For everyone else: eat more of them. Your body will thank you, even if your dinner companions don’t.