Broccoli: Nutrition Facts, Health Benefits, and Why It Earns Its Reputation as a Superfood

Broccoli has been called a superfood so many times the word has almost lost its meaning — but in broccoli’s case, the reputation is largely earned. At just 35 calories per 100g cooked, it delivers 118% of the daily Vitamin K requirement, 72% of Vitamin C, 27% of folate, plenty of fiber, and a collection of plant compounds — particularly sulforaphane — that are among the most studied food compounds in cancer prevention research.

It’s one of the lowest-calorie foods available and one of the most nutrient-dense. That combination — a lot of nutritional value for very few calories — is genuinely rare, and it makes broccoli one of the most worthwhile foods to include in any health-conscious diet.

Broccoli Nutrition Facts (per 100g, cooked)

USDA’s figures for broccoli boiled and drained, without salt.

Broccoli Nutrition Facts (per 100g, raw vs. cooked)

Cooking changes some of broccoli’s nutrients — understanding the differences helps you choose the best preparation for your goals:

Raw figures are from USDA’s newer Foundation Foods analysis of raw broccoli; cooked figures from USDA’s SR Legacy data. Because they come from different samples and analyses, some differences — such as the higher folate and Vitamin K per 100g of cooked broccoli — reflect natural variation between samples (and some water loss in cooking) rather than cooking adding nutrients.

The most important practical finding: raw broccoli keeps more Vitamin C and far more sulforaphane-forming capacity, while boiling loses a share of the water-soluble vitamins. Light steaming gives a good balance between the two.

Vitamins in Broccoli (per 100g, cooked)

Standout: Broccoli’s vitamin profile is outstanding for a 35-calorie food. It provides 118% of the daily Vitamin K requirement per 100g cooked — one of the best Vitamin K sources among common vegetables. Its Vitamin C (72% DV cooked, and about 100% raw) is higher than most people realize — per 100g, broccoli is comparable to or richer than many citrus fruits. Folate (27% DV), pantothenic acid and B6 (12% DV each), and Vitamin E (10% DV) round out an impressive vitamin profile.

Minerals in Broccoli (per 100g, cooked)

Worth noting: Broccoli’s individual mineral percentages are modest, but the combination comes with very few calories: manganese (8% DV), copper (7% DV), potassium (293mg), and phosphorus and magnesium (5% DV each). Its calcium (40mg per 100g) is also worth noting: it’s unusually well absorbed — a higher percentage than the calcium in milk — though the amount per serving is much smaller than in dairy, so broccoli complements rather than replaces other calcium sources for people avoiding dairy.

The Sulforaphane Story: Broccoli’s Most Studied Compound

Sulforaphane is the compound that makes broccoli one of the most studied foods in cancer prevention research. Understanding how it forms — and how to get the most of it — changes how you think about preparing and eating broccoli.

What Is Sulforaphane?

Sulforaphane is an isothiocyanate — a sulfur-containing compound produced when broccoli’s cells are damaged. It doesn’t exist ready-made in intact broccoli; it’s created by a reaction between two components stored separately in the plant:

• Glucoraphanin — the precursor compound stored in broccoli’s cells
• Myrosinase — an enzyme stored separately in the plant tissue

When broccoli is chopped or chewed, the two come into contact and myrosinase converts glucoraphanin into sulforaphane. This is a plant defense mechanism — sulforaphane helps deter insects and microbes.

The Heat Problem

Here’s the key practical issue: heat destroys myrosinase. When broccoli is cooked thoroughly — especially boiled — the enzyme is deactivated before it can convert much glucoraphanin into sulforaphane. Glucoraphanin itself survives cooking, and some of it can still be converted by bacteria in your gut, but much less efficiently.

This means well-cooked broccoli produces far less sulforaphane than raw or lightly cooked broccoli, even though it still contains the precursor.

How to Get More Sulforaphane

Chop before cooking — cutting broccoli while myrosinase is still active lets some sulforaphane form before heat deactivates the enzyme. A common tip is to chop broccoli and leave it for around 30–40 minutes before cooking.

Eat some raw — raw broccoli keeps its myrosinase fully active, so chewing raw florets forms sulforaphane as you eat. Raw florets in salads or with dips preserve this benefit.

Steam lightly rather than boil — brief steaming (around 3–4 minutes) preserves much more myrosinase activity than boiling.

Add mustard powder or a little raw broccoli to cooked broccoli — a fascinating research finding. Mustard seeds contain their own myrosinase, and studies have found that sprinkling a little mustard powder over cooked broccoli substantially increases sulforaphane formation. Eating a small amount of raw broccoli alongside cooked broccoli works in a similar way.

Broccoli sprouts — young broccoli sprouts contain 10–100 times more glucoraphanin than mature broccoli, making them the richest source of sulforaphane potential. Even a small handful of raw sprouts on salads or sandwiches provides a large amount.

What Sulforaphane Does in the Body

Cancer research — sulforaphane is one of the most studied natural compounds in cancer prevention research. In laboratory and animal studies, it works through several mechanisms:

• Activating Nrf2 — a master regulator of the body’s antioxidant and detoxification defenses. Sulforaphane is one of the most potent natural activators of Nrf2, which switches on a large set of protective genes.
• Inducing “phase 2” detoxification enzymes — enzymes that help neutralize carcinogens and other harmful compounds and prepare them for excretion.
• Inhibiting histone deacetylases (HDACs) — enzymes that can silence tumor-suppressing genes.
• Promoting the death of cancer cells — in laboratory studies, sulforaphane triggers programmed cell death in cancer cells.

In population studies, higher intake of cruciferous vegetables (broccoli, cauliflower, Brussels sprouts, kale, and cabbage) has been associated with lower risks of some cancers in a number of studies — though results vary between cancer types and studies.

Anti-inflammatory effects — sulforaphane reduces the activity of NF-κB, a key switch for inflammation, lowering the production of inflammatory signaling molecules in laboratory studies.

Brain health — sulforaphane can reach the brain and activate Nrf2 there. Small clinical trials have explored sulforaphane for autism spectrum disorder symptoms, with mixed results, and research on other brain conditions is at an early stage.

Gut health — sulforaphane is active against Helicobacter pylori, the bacterium behind most stomach ulcers and a major risk factor for stomach cancer. Small studies have found that eating broccoli sprouts reduced H. pylori activity in the stomach, though it doesn’t replace medical treatment.

Health Benefits of Broccoli

Exceptional Vitamin K for Bone and Blood Health

At 118% of the daily Vitamin K requirement per 100g cooked, broccoli is one of the best dietary Vitamin K sources among common vegetables. Vitamin K is needed for:

Bone health — activating osteocalcin, a protein that helps bind calcium into bone. Low Vitamin K intake has been associated with lower bone density and higher fracture risk in observational studies.

Arterial health — activating matrix Gla protein (MGP), which helps prevent calcium from building up in artery walls. Evidence that higher intake reduces arterial calcification is strongest for Vitamin K2 from animal and fermented foods, rather than the K1 found in vegetables.

Blood clotting — essential for making the clotting factors that allow blood to clot when needed.

Outstanding Vitamin C

At 72% of daily Vitamin C per 100g cooked — and about 100% raw — broccoli is one of the richest vegetable sources of Vitamin C, rivaling citrus fruits while also providing fiber, folate, and Vitamin K.

Vitamin C in broccoli supports:

Collagen formation — Vitamin C is an essential cofactor for the enzymes that stabilize collagen fibers, giving connective tissue its strength. Adequate Vitamin C supports skin, joint cartilage, tendons, and wound healing.

Immune function — Vitamin C supports several aspects of immune defense, including the function of white blood cells.

Iron absorption — Vitamin C substantially increases the absorption of non-haem iron from plant foods eaten at the same meal. Eating broccoli with iron-rich plant foods such as lentils, spinach, or fortified grains is a particularly useful habit for plant-based eaters.

Antioxidant protection — as the main water-soluble antioxidant, Vitamin C neutralizes free radicals throughout the body and helps regenerate other antioxidants, including Vitamin E.

Cancer Prevention — What the Evidence Shows

Broccoli’s potential cancer-preventive properties are among the most researched in nutrition science. The evidence comes from several directions:

Population studies — many cohort and case-control studies have linked regular cruciferous vegetable intake with lower risks of certain cancers, including colorectal, lung, and bladder cancer in some analyses, though the findings aren’t consistent across all studies or cancer types.

Mechanistic research — sulforaphane, indole-3-carbinol, and other broccoli compounds have shown anti-cancer effects through multiple mechanisms in laboratory and animal research.

Clinical studies — sulforaphane from broccoli sprouts has been tested in small early-phase clinical studies, with some promising results on biological markers.

The honest qualification: population studies show associations, not proof of cause and effect — people who eat lots of broccoli also tend to eat healthier diets overall — and laboratory findings don’t always translate into benefits in people. The evidence is strong enough to make broccoli a sensible part of a cancer-protective diet, but not to claim that broccoli prevents or cures cancer.

Heart Health

Broccoli fits well into a heart-healthy diet:

Fiber — 3.3g per 100g cooked contributes to the fiber intake linked with lower heart disease risk.

Potassium — 293mg per 100g helps counter sodium’s effect on blood pressure.

Sulforaphane and antioxidants — reduce inflammation and oxidative stress in laboratory studies, and may support the health of blood vessel linings.

Folate — helps keep homocysteine in check as part of a healthy diet, though B-vitamin supplements haven’t clearly reduced heart attacks in trials.

Diets rich in vegetables, including crucifers like broccoli, are consistently associated with lower cardiovascular risk in large population studies.

Eye Health

Broccoli contains the carotenoids lutein and zeaxanthin, which concentrate in the macula of the eye, where they help filter blue light and are associated with lower risk of age-related macular degeneration. It also provides some beta-carotene (9% DV of Vitamin A per 100g cooked).

Digestive Health

Broccoli supports gut health in several ways:

Fiber — 3.3g per 100g cooked, a mix of soluble and insoluble fiber that feeds beneficial gut bacteria and supports regularity.

Glucosinolates — the family of compounds sulforaphane comes from interacts with gut bacteria, which can convert some of them into active compounds.

Activity against H. pylori — as described above, small studies of broccoli sprouts have found reduced H. pylori activity in the stomach.

Blood Sugar Management

With only about 4g of digestible carbohydrate per 100g cooked (7.2g of carbohydrate, 3.3g of it fiber), broccoli has a negligible effect on blood sugar — so little that its glycaemic index isn’t usually measured. Adding broccoli to meals also adds fiber and volume, which helps moderate the overall blood sugar response.

In one small clinical trial, a broccoli sprout extract rich in sulforaphane lowered fasting blood sugar in people with obesity and poorly controlled type 2 diabetes — an interesting finding that needs confirming in larger studies.

Detoxification Support — the Real Version

Sulforaphane’s activation of phase 2 detoxification enzymes is one of its best-documented properties. These enzymes, including glutathione S-transferases, neutralize carcinogens and other harmful compounds and prepare them for excretion.

This isn’t the pseudoscientific “cleansing” promoted by many wellness products — it’s a specific, measurable biochemical process. In a clinical trial in a heavily polluted region of China, a daily broccoli sprout drink increased the excretion of certain airborne pollutants, such as benzene, in urine.

Broccoli for Athletes and Active People

Broccoli is particularly valuable for anyone training seriously — for reasons that go beyond its nutrients per calorie:

Vitamin C for Collagen and Recovery

Athletes place repeated stress on tendons, ligaments, and cartilage — collagen-based tissues that depend on adequate Vitamin C for repair and maintenance. Broccoli’s 72% DV of Vitamin C per 100g cooked directly supports the collagen formation these tissues need.

Antioxidant and Anti-Inflammatory Support

Intense training produces short-term inflammation and oxidative stress. Broccoli’s Vitamin C, Vitamin E, and sulforaphane contribute to the antioxidant- and plant-compound-rich diet that supports recovery — unlike high-dose antioxidant supplements, which in some studies have blunted training adaptations.

Vitamin K for Bone Health

Weight-bearing exercise and resistance training support bone density — alongside the right nutrients. Broccoli’s 118% DV of Vitamin K per 100g contributes to the Vitamin K that, together with calcium, Vitamin D, and protein, supports healthy bones.

Folate for Red Blood Cell Production

Folate (27% DV per 100g cooked) is needed to produce red blood cells, which carry oxygen to working muscles — important for endurance and high-volume training.

High Volume, Minimal Calories

At 35 calories per 100g, broccoli lets athletes in calorie-restricted phases (cutting or making weight) eat large, satisfying portions while saving calories for protein and other essentials. A 200g serving of cooked broccoli provides just 70 calories, along with more than twice the daily Vitamin K requirement, well over a full day’s Vitamin C, over half the daily folate, and 6.6g of fiber.

Raw vs. Cooked Broccoli: A Practical Guide

This is one of the most practical questions in broccoli nutrition — and the answer depends on what you’re aiming for:

Eat raw for:

• The most sulforaphane (myrosinase fully active)
• The most Vitamin C

Eat lightly steamed for:

• Easier digestion for people who find raw broccoli causes bloating
• Softened cell walls, which can make some nutrients, such as carotenoids, easier to absorb
• Still keeping a good share of Vitamin C and sulforaphane potential, especially if chopped and rested before steaming

Avoid long boiling because:

• Boiling leaches water-soluble vitamins (Vitamin C, B vitamins, and folate) into the cooking water — prolonged boiling can lose up to half of some of them
• It quickly destroys myrosinase, sharply reducing sulforaphane formation
• If you do boil broccoli, keep it brief, or use the water in soups or sauces

A good everyday approach:

1. Chop broccoli into florets
2. Leave for 30–40 minutes, letting sulforaphane form while myrosinase is active
3. Steam lightly for 3–4 minutes — tender but still bright green and slightly firm
4. Serve straight away — or add a pinch of mustard powder for an extra boost

Broccoli vs. Its Close Relatives

Broccoli belongs to the Brassica (cruciferous) family — vegetables that share glucosinolate chemistry, though each contains a different mix of glucosinolates. Here’s how it compares with some close relatives, all cooked:

Broccoli and Brussels sprouts are closely matched on Vitamin C and Vitamin K, broccoli raab leads on Vitamin K, and broccoli has the most fiber of the group. Broccoli — and especially broccoli sprouts — stands out as the richest source of glucoraphanin, the precursor of sulforaphane; other crucifers provide different glucosinolates with related effects. Rotating through several cruciferous vegetables, including cauliflower, cabbage, kale, and bok choy, gives you a broader range of these compounds than any single one.

Practical Ways to Include Broccoli in Your Diet

Lightly steamed alongside protein — the simplest and one of the best preparations: 200g of steamed broccoli with grilled chicken or salmon, dressed with olive oil, garlic, and lemon.

Raw in salads — florets add crunch, nutrients, and sulforaphane to any salad, and their Vitamin C helps you absorb iron from iron-rich salad ingredients.

Stir-fried — a short time over high heat (2–3 minutes) keeps color, texture, and more nutrients than boiling, with great flavor from light caramelization.

Roasted — broccoli roasted at 200°C with olive oil develops a nutty, slightly crispy character that wins over even broccoli skeptics. Some sulforaphane potential is lost, but the olive oil helps you absorb fat-soluble vitamins (K, E, and beta-carotene).

In soups and stews — add broccoli near the end of cooking to keep more nutrients. Blended broccoli soup keeps the water-soluble vitamins that leach into the cooking liquid.

As broccoli rice — pulsed raw in a food processor to a rice-like texture, broccoli makes a very low-calorie, high-nutrient substitute for rice in bowls and stir-fries.

Broccoli sprouts — a small handful of raw sprouts on sandwiches, salads, or grain bowls provides the most sulforaphane potential of any form of broccoli.

With dips — raw florets with hummus, tzatziki, or a nut butter dip make a balanced snack, combining broccoli’s vitamins with protein and healthy fat.

Potential Considerations

Thyroid and goitrogens — broccoli contains compounds that, in very large amounts, can interfere with the thyroid’s use of iodine. This is mainly relevant for people with low iodine intake who eat very large amounts of raw cruciferous vegetables; cooking reduces the effect. For people with normal thyroid function eating normal amounts, it isn’t a meaningful concern.

Blood thinners (warfarin) — broccoli’s high Vitamin K content is its most clinically significant consideration. Vitamin K affects how warfarin works, so people taking warfarin should keep their broccoli and leafy green intake consistent rather than suddenly increasing or decreasing it. Consistency matters more than the absolute amount.

Bloating and digestive discomfort — broccoli’s fiber and some of its fermentable carbohydrates (FODMAPs) can cause gas and bloating in some people, especially those with IBS. The florets are lower in FODMAPs than the stalks, cooking helps, and starting with smaller portions lets the gut adapt.

Kidney stones — broccoli is low in oxalate, unlike spinach, so it’s generally a good vegetable choice for people prone to calcium oxalate kidney stones.

Nutrient data: USDA FoodData Central, SR Legacy — broccoli, cooked, boiled, drained, without salt (FDC ID 169967). Raw broccoli: Foundation Foods (FDC ID 747447). Comparisons from SR Legacy, all cooked: Brussels sprouts (FDC ID 169971), broccoli raab (FDC ID 170382), and Chinese broccoli (FDC ID 169392). % Daily Values use the FDA’s current Daily Values.