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 lost its meaning — but in broccoli’s case, the designation is genuinely earned. At just 35 calories per 100g, it delivers 118% of the daily Vitamin K requirement, 72% of Vitamin C, 52% of Vitamin A, meaningful folate, fiber, and a collection of bioactive compounds — particularly sulforaphane — that have some of the most impressive cancer-preventive research of any food compound studied.

It is simultaneously one of the lowest-calorie foods available and one of the highest nutrient-density foods available. That combination — extraordinary nutritional value for almost no caloric cost — is genuinely rare and makes broccoli one of the most important foods to include in any health-conscious diet.

Broccoli Nutrition Facts (per 100g, cooked)

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

Cooking significantly affects broccoli’s nutritional profile — understanding the differences helps you choose the best preparation for your goals:

The most important practical finding: raw broccoli retains significantly more Vitamin C and sulforaphane, while cooked broccoli provides more bioavailable Vitamin K and slightly more fiber. Lightly steaming — rather than boiling — preserves the best of both worlds.

Vitamins in Broccoli (per 100g, cooked)

Standout: Broccoli’s vitamin profile is extraordinary for a 35-calorie food. It provides 118% of the daily Vitamin K requirement — making it one of the most concentrated Vitamin K sources available from any common vegetable. Its Vitamin C content (72% DV per 100g cooked — and 99% DV raw) is exceptional and significantly higher than most people associate with this vegetable — broccoli contains nearly as much Vitamin C as oranges per 100g. The Vitamin A (52% DV from beta-carotene) rounds out one of the most impressive vitamin profiles of any vegetable.

Minerals in Broccoli (per 100g, cooked)

Standout: While broccoli’s individual mineral percentages appear modest, the combination at just 35 calories per 100g is genuinely impressive. Manganese (13% DV) for bone formation and antioxidant defence, potassium (293mg) for heart and muscle function, and phosphorus (10% DV) for energy production — all from a food with negligible calories and no fat. The calcium content (40mg per 100g) is also worth noting — it’s in a highly bioavailable form and is a meaningful contributor to calcium intake for people avoiding dairy.

The Sulforaphane Story: Broccoli’s Most Important Bioactive Compound

Sulforaphane is the compound that elevates broccoli from a nutritious vegetable to one of the most studied foods in cancer prevention research. Understanding how it forms, how it works, and how to maximize it from your broccoli changes how you think about preparing and eating this vegetable.

What Is Sulforaphane?

Sulforaphane is an isothiocyanate — a sulphur-containing compound produced when broccoli cells are damaged. It doesn’t exist preformed in intact broccoli — it’s created through an enzymatic reaction between two precursor compounds:

• Glucoraphanin — the precursor compound stored in broccoli cells
• Myrosinase — an enzyme stored separately in different cells

When broccoli is chopped, chewed, or otherwise physically damaged, these two compounds come into contact and myrosinase converts glucoraphanin into sulforaphane. This is a plant defence mechanism — sulforaphane is antimicrobial and deters insects and pathogens.

The Heat Problem

Here’s the critical practical issue: heat destroys myrosinase. When you cook broccoli at high temperatures — boiling, steaming, microwaving — myrosinase is deactivated before it can convert glucoraphanin to sulforaphane. Glucoraphanin itself survives cooking, but without myrosinase it cannot be converted to sulforaphane in the vegetable.

This means well-cooked broccoli contains very little sulforaphane — even though it still contains the glucoraphanin precursor.

How to Maximize Sulforaphane

Chop or crush before cooking — the most important technique. Cutting or chewing broccoli while myrosinase is still active allows some sulforaphane formation before heat deactivates the enzyme. Chop broccoli and let it sit for 30–40 minutes before cooking — this allows maximum myrosinase activity before heat deactivates it.

Eat some raw — raw broccoli retains fully active myrosinase. Chewing raw broccoli creates sulforaphane in your mouth and stomach as you eat. Raw broccoli florets in salads or with dips preserve this benefit.

Light steaming is far better than boiling — brief steaming (3–4 minutes) at lower temperatures deactivates myrosinase more slowly than boiling. Short steaming preserves more sulforaphane-forming capacity than any other cooking method.

Add mustard seed or raw broccoli to cooked broccoli — this is a fascinating research finding. Mustard seeds contain myrosinase — adding a pinch of mustard powder or ground mustard seed to cooked broccoli provides the myrosinase enzyme needed to convert the surviving glucoraphanin to sulforaphane in your digestive system. Similarly, eating a small amount of raw broccoli alongside cooked broccoli provides the myrosinase missing from the cooked portion.

Broccoli sprouts — broccoli sprouts contain 10–100x more glucoraphanin than mature broccoli — making them the most sulforaphane-efficient form of broccoli available. Even small amounts of raw broccoli sprouts added to salads or sandwiches provide enormous sulforaphane potential.

What Sulforaphane Does in the Body

Cancer prevention — sulforaphane is one of the most studied natural cancer-preventive compounds available. Its mechanisms include:

• Activation of Nrf2 — the master regulator of the body’s antioxidant defense system. Sulforaphane powerfully activates Nrf2, which upregulates hundreds of detoxification and antioxidant genes simultaneously.
• Phase 2 enzyme induction — sulforaphane induces phase 2 detoxification enzymes in the liver that neutralize carcinogens and reactive oxygen species before they can damage DNA.
• Histone deacetylase (HDAC) inhibition — sulforaphane inhibits HDACs — enzymes that can silence tumor suppressor genes. By inhibiting HDACs, sulforaphane may help reactivate genes that suppress cancer cell growth.
• Apoptosis induction — sulforaphane promotes programmed cell death in cancer cells while leaving normal cells unaffected — one of the most valuable properties any anti-cancer compound can have.

Population studies consistently show higher cruciferous vegetable consumption (broccoli, cauliflower, Brussels sprouts, kale) is associated with meaningfully lower rates of several cancers — particularly colorectal, lung, breast, prostate, and bladder cancers.

Anti-inflammatory effects — sulforaphane inhibits NF-κB — the master inflammatory transcription factor — reducing the production of inflammatory cytokines. This anti-inflammatory mechanism contributes to broccoli’s broader health benefits beyond cancer prevention.

Brain health and neuroprotection — sulforaphane crosses the blood-brain barrier and activates Nrf2 in brain tissue, providing antioxidant and anti-inflammatory protection against neurodegeneration. Research has found potential benefits for autism spectrum disorder symptoms, traumatic brain injury recovery, and age-related cognitive decline.

Gut health — sulforaphane has antimicrobial properties against Helicobacter pylori — the bacterium responsible for most stomach ulcers and a significant risk factor for stomach cancer. Research has found broccoli sprout consumption reduces H. pylori burden in the stomach.

Health Benefits of Broccoli

Exceptional Vitamin K for Bone and Cardiovascular Health

At 118% of daily Vitamin K requirement per 100g cooked, broccoli is one of the most important dietary Vitamin K sources available. Vitamin K is essential for:

Bone mineralization — activating osteocalcin, the protein that binds calcium into bone tissue. Without adequate Vitamin K, calcium cannot be properly incorporated into bone matrix regardless of calcium intake — making Vitamin K as important as calcium for bone density.

Arterial health — activating matrix Gla protein (MGP), which prevents calcium from depositing in arterial walls. Adequate Vitamin K literally directs calcium into bones and away from arteries — one of the most important cardiovascular-protective mechanisms from diet.

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

For people concerned about osteoporosis or cardiovascular health, regular broccoli consumption provides one of the most important dietary contributions to Vitamin K adequacy.

Outstanding Vitamin C Source

At 72% of daily Vitamin C per 100g cooked — and 99% raw — broccoli is one of the richest Vitamin C sources available from any food, comfortably rivaling citrus fruits while providing significantly more protein, fiber, and Vitamin K.

Vitamin C in broccoli supports:

Collagen synthesis — Vitamin C is the essential cofactor for the enzymes that crosslink collagen fibers, giving connective tissue its tensile strength. Adequate Vitamin C from broccoli directly supports skin elasticity, joint cartilage integrity, tendon strength, and wound healing.

Immune function — Vitamin C supports multiple aspects of immune defense including neutrophil function, natural killer cell activity, and lymphocyte proliferation. Consistent intake from whole food sources like broccoli maintains the immune support that single large-dose supplements cannot replicate as effectively.

Iron absorption enhancement — Vitamin C dramatically enhances the absorption of non-haem iron (from plant sources) consumed at the same meal. Eating broccoli alongside iron-rich plant foods (lentils, spinach, fortified grains) can increase iron absorption by up to 3-fold — a critically important interaction for plant-based eaters.

Antioxidant protection — as the primary water-soluble antioxidant, Vitamin C neutralists free radicals in aqueous environments throughout the body and regenerates other antioxidants including Vitamin E.

Cancer Prevention — The Strongest Evidence

Broccoli’s cancer-preventive properties represent some of the most consistent findings in nutritional epidemiology. The evidence operates at multiple levels:

Population studies — numerous large cohort studies have found that people who eat cruciferous vegetables (including broccoli) regularly have significantly lower risks of several cancers. A 2011 meta-analysis found that higher cruciferous vegetable consumption was associated with a 16% reduction in overall cancer risk. Individual cancer types show even stronger associations — colorectal cancer risk is particularly consistently reduced in high cruciferous vegetable consumers.

Mechanistic research — sulforaphane (discussed above), indole-3-carbinol, and other broccoli bioactives have demonstrated anti-cancer effects through multiple mechanisms in laboratory and animal research.

Clinical trials — sulforaphane from broccoli sprouts has been tested in clinical trials for several cancer types with promising results in early-phase studies.

The honest qualification: population studies show associations, not proven causation — people who eat lots of broccoli also tend to eat overall healthier diets. And laboratory/animal research doesn’t always translate to clinical benefit. The cancer-preventive evidence for broccoli is compelling but not definitive proof. It’s strong enough to warrant regular consumption as part of a cancer-preventive dietary pattern — not strong enough to claim broccoli cures or prevents cancer.

Heart Health

Broccoli supports cardiovascular health through multiple complementary mechanisms:

Vitamin K — reduces arterial calcification through MGP activation as discussed above.

Sulforaphane — reduces arterial inflammation through NF-κB inhibition and improves endothelial function — the health of the cells lining blood vessels that regulate vascular tone and prevent clotting.

Fiber — 3.3g per 100g cooked contributes to the soluble fiber intake that lowers LDL cholesterol through bile acid binding.

Potassium — 293mg per 100g supports healthy blood pressure by counteracting sodium’s pressor effects.

Folate — reduces homocysteine — elevated homocysteine is an independent cardiovascular risk factor that damages arterial walls.

Antioxidants — prevent LDL oxidation — oxidised LDL is the most damaging form for arterial health and a primary driver of atherosclerotic plaque formation.

Research has found regular broccoli consumption associated with reduced LDL cholesterol, improved arterial flexibility, and lower overall cardiovascular disease risk in large population studies.

Eye Health

Broccoli contains two carotenoids — lutein and zeaxanthin — that are specifically concentrated in the macula of the eye where they filter harmful blue light and protect against age-related macular degeneration and cataract formation. Combined with its high beta-carotene content (providing 52% of Vitamin A DV per 100g), broccoli is one of the most eye-health-supportive foods available.

Digestive Health

Broccoli supports gut health through several mechanisms:

Fibre — 3.3g per 100g cooked provides both soluble and insoluble fibre that feeds beneficial gut bacteria (prebiotic effect), supports bowel regularity, and reduces colorectal cancer risk.

Glucosinolates — the family of compounds from which sulforaphane is derived also includes other bioactives with prebiotic properties that selectively promote the growth of beneficial gut bacteria.

Antimicrobial properties — sulforaphane’s activity against H. pylori is one of the most clinically relevant digestive health benefits. Research has found that regular broccoli sprout consumption significantly reduces H. pylori density in the stomach — potentially reducing the risk of peptic ulcers and stomach cancer.

Anti-inflammatory gut effects — broccoli bioactives reduce intestinal inflammation, supporting gut barrier integrity and reducing the intestinal permeability associated with chronic digestive conditions.

Blood Sugar Management

Broccoli has a glycaemic index of approximately 10–15 — one of the lowest of any food. Its combination of fiber, protein, and chromium (which enhances insulin sensitivity) produces virtually no blood sugar response while providing substantial nutritional value. Including broccoli regularly in meals with higher-GI carbohydrates meaningfully reduces the overall glycaemic load of those meals.

Research has found that sulforaphane specifically improves insulin sensitivity in people with type 2 diabetes — suggesting broccoli has direct beneficial effects on glucose metabolism beyond simple carbohydrate management.

Detoxification Support

Sulforaphane’s activation of phase 2 detoxification enzymes in the liver is one of its most important and most underappreciated properties. These enzymes — glutathione S-transferases, glucuronyl transferases, and others — neutralize and prepare environmental toxins, carcinogens, and metabolic waste products for excretion.

This detoxification support is not the pseudoscientific “cleansing” promoted by many wellness products — it’s a specific, mechanistically understood biochemical process with decades of research supporting its protective role. Regular broccoli consumption genuinely enhances the liver’s ability to process and eliminate harmful compounds.

Broccoli for Athletes and Active People

Broccoli is particularly valuable for anyone training seriously — for reasons that go well beyond its calorie-to-nutrient ratio:

Vitamin C for Collagen and Recovery

Athletes place significant repetitive stress on tendons, ligaments, and cartilage — the collagen-dependent connective tissues that are most vulnerable to overuse injury and most dependent on adequate Vitamin C for repair and maintenance. Broccoli’s 72% DV of Vitamin C per 100g (cooked) directly supports the collagen synthesis needed for connective tissue integrity and recovery from training loads.

Anti-Inflammatory Support

Intense training produces acute inflammation through exercise-induced muscle damage and oxidative stress. Broccoli’s sulforaphane, Vitamin C, and Vitamin E work through complementary antioxidant and anti-inflammatory mechanisms to support the resolution of this post-exercise inflammation — without suppressing the beneficial inflammatory signals needed for adaptation.

Vitamin K for Bone Density

Weight-bearing exercise and resistance training support bone density — but only when the nutritional building blocks are present. Broccoli’s 118% DV of Vitamin K per 100g is one of the most important single-food contributions to the Vitamin K adequacy needed for proper calcium incorporation into bone. Athletes who consume adequate Vitamin K alongside calcium maintain better bone mineral density and lower fracture risk.

Folate for Red Blood Cell Production and Recovery

Folate (16% DV per 100g) supports the red blood cell production that carries oxygen to working muscles. Adequate folate helps maintain the aerobic capacity and oxygen transport efficiency that endurance and high-volume training depend on.

Chromium for Insulin Sensitivity

Broccoli is one of the richest dietary sources of chromium — a trace mineral that enhances insulin sensitivity and glucose uptake into cells. For athletes managing carbohydrate intake and glycogen storage, adequate chromium from foods like broccoli supports the insulin sensitivity that efficiently shuttles glucose into muscle cells for glycogen replenishment after training.

High Volume, Minimal Calories

At 35 calories per 100g, broccoli allows athletes in calorie-restricted phases (cutting, weight class management) to eat large, satisfying portions while leaving ample caloric budget for protein and other essential nutrients. A 200g serving of broccoli provides only 70 calories — less than half a cup of rice — while contributing 2% of daily Vitamin K, meaningful Vitamin C, folate, and fibre.

Raw vs. Cooked Broccoli: The Definitive Guide

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

Eat raw for:

• Maximum sulforaphane (myrosinase fully active)
• Maximum Vitamin C (27% more than cooked)
• Maximum glucosinolate activity

Eat lightly steamed for:

• Better Vitamin K bioavailability (cooking slightly increases it)
• More digestible for people who find raw broccoli causes bloating
• Better cell wall breakdown improving general nutrient availability
• Still retains meaningful sulforaphane if chopped and rested before steaming

Avoid boiling for:

• Boiling leaches water-soluble vitamins (Vitamin C, B vitamins, folate) into the cooking water — losing up to 50% of some nutrients
• Destroys myrosinase rapidly eliminating sulforaphane production
• If boiling, use the water in soups or sauces to recover leached nutrients

The optimal approach:

1. Chop broccoli into florets
2. Let it sit for 30–40 minutes (maximizes sulforaphane formation while myrosinase is active)
3. Steam lightly for 3–4 minutes — tender but still bright green and slightly firm
4. Serve immediately

This simple preparation sequence dramatically maximizes the sulforaphane content of cooked broccoli compared to standard cooking approaches.

Broccoli vs. Other Cruciferous Vegetables

Broccoli belongs to the Brassica family — a group of vegetables sharing the glucosinolate chemistry that produces sulforaphane and related compounds:

Broccoli stands out for its exceptional sulforaphane potential alongside very strong Vitamin C and Vitamin K content. Brussels sprouts and kale exceed it in some vitamins but have less accessible sulforaphane. Broccoli sprouts are the sulforaphane champions — with up to 100x more glucoraphanin per gram than mature broccoli.

For maximum health benefit, rotating through multiple cruciferous vegetables provides complementary phytochemical profiles that are collectively more protective than any single variety.

Practical Ways to Include Broccoli in Your Diet

Lightly steamed alongside protein — the simplest and most nutritionally optimal preparation. 200g steamed broccoli with grilled chicken or salmon, seasoned with olive oil, garlic, and lemon.

Raw in salads — florets add crunch, nutrition, and sulforaphane to any salad. Particularly effective in salads with iron-rich ingredients where broccoli’s Vitamin C enhances iron absorption.

Stir-fried — high heat for a short time (2–3 minutes) preserves color, texture, and more nutrients than boiling while producing excellent flavor through slight caramelisation.

Roasted — broccoli roasted at 200°C with olive oil and seasoning develops a nutty, slightly crispy character that converts even broccoli sceptics. Some sulforaphane is lost but fat-soluble vitamins (K, E, beta-carotene) are better absorbed alongside the olive oil.

In soups and stews — broccoli added near the end of cooking retains more nutrients than vegetables cooked for the full duration. Blended broccoli soup is nutritionally excellent when the cooking liquid is used as the soup base — capturing the water-soluble vitamins.

As broccoli rice — pulsed raw in a food processor to a rice-like consistency, broccoli rice is an exceptional low-calorie, high-nutrient substitute for rice in bowls, stir-fries, and as a side dish.

Broccoli sprouts — adding a small handful of raw broccoli sprouts to sandwiches, salads, or grain bowls provides the highest sulforaphane concentration available from any broccoli form.

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

Potential Considerations

Thyroid and goitrogens — broccoli contains goitrogens — compounds that can interfere with thyroid hormone synthesis by competing with iodine uptake. In people with already-low iodine intake or existing hypothyroidism, very large amounts of raw cruciferous vegetables could theoretically worsen thyroid function. Cooking significantly reduces goitrogenic activity. For people with normal thyroid function eating reasonable amounts (1–2 servings per day), this is not a meaningful concern.

Blood thinners (warfarin) — broccoli’s very high Vitamin K content is the most clinically significant consideration. Vitamin K directly affects warfarin’s anticoagulant activity. People taking warfarin should maintain consistent broccoli and leafy green intake rather than suddenly increasing or decreasing consumption. Consistency matters more than the absolute amount.

Bloating and digestive discomfort — broccoli contains FODMAPs and fibre that cause gas and bloating in some people, particularly those with IBS. Cooking reduces FODMAPs somewhat. Starting with smaller cooked portions and gradually increasing allows the gut microbiome to adapt.

Kidney stones — broccoli contains oxalates (though less than spinach). People with a history of calcium oxalate kidney stones should be mindful of portion sizes and ensure adequate hydration.