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Broccoli
Brokkoli · (Brassica oleracea var. italica)
Cabbage family (Brassicaceae)
Description
Broccoli is cut before it blooms: the green head is a mass of tightly packed, still-closed flower buds on a fleshy stalk, harvested from June to October. At roughly 90 milligrams of vitamin C per 100 grams it ranks among the most generous vegetables, and it adds vitamin K1, folate and the carotenoids lutein and zeaxanthin. Its best-known constituent is the mustard-oil glycoside glucoraphanin: only when the tissue is cut or chewed does the plant's own enzyme myrosinase release sulforaphane from it, a compound shown in studies to switch on the body's detoxification enzymes. Because that enzyme is heat-sensitive, brief steaming of five to seven minutes preserves considerably more of it than boiling in plenty of water. Sprouts three to four days old are especially rich in glucoraphanin. Stalk and leaves are just as edible as the florets.
Raw broccoli (fresh florets and stems) delivers very high vitamin C density (~90 mg/100 g, USDA) and preserves more glucosinolates than cooking, because myrosinase — the enzyme converting glucoraphanin to sulforaphane — is inactivated at cooking temperatures. Raw consumption (briefly chewed then eaten) or brief blanching + cooling is considered optimal for maximum sulforaphane yield. Regular intake of raw or lightly steamed Brassica vegetables is associated with higher intake of antioxidants, folate, and vitamin K.
Broccoli sprouts (3–4 day old seedlings) contain 10- to 100-fold higher glucoraphanin concentrations than mature broccoli (Fahey et al., PNAS 1997). Preparation: germinate seeds in a sprouting jar (rinse 2–3× daily, 3–4 days), then consume fresh. Studies show 40 g sprouts per day significantly increases systemic sulforaphane biomarkers. Broccoli sprouts are therefore the most concentrated dietary source of glucoraphanin/sulforaphane and are the subject of numerous clinical trials on detoxification enzymes (phase II enzymes) and antioxidant response (Nrf2 activation).
Steamed broccoli (5–7 minutes on low heat, in a steamer basket or with minimal water) retains the majority of water-soluble vitamins (vitamin C, folate) and minerals better than boiling, where nutrients leach into cooking water. The cooking water can be reused as a nutrient-rich broth. Traditional kitchen practice recommends brief steaming with a little olive oil and garlic — also sensorially beneficial, as sulforaphane and indoles are somewhat volatile.
Sulforaphane (formed from glucoraphanin via myrosinase) activates the Nrf2 transcription factor and induces phase II detoxification enzymes (e.g. glutathione S-transferase, NAD(P)H quinone oxidoreductase). Clinical studies demonstrate sulforaphane uptake after broccoli consumption and elevated antioxidant markers in plasma. EFSA has not adopted an authorised health claim for sulforaphane; however, the evidence base for antioxidant capacity and enzyme induction is clinically well established. Daily intake of 80–200 g fresh or lightly steamed broccoli covers a significant part of the vitamin C, vitamin K, and folate requirement.
In the kitchen broccoli is used versatilely as a side vegetable, in soups, pasta dishes, raw in salads, and as a gratin ingredient. Southern Italian cuisine (origin region Calabria/Campania) traditionally combines broccoli with olive oil, garlic, chilli, and lemon — a preparation that can optimise glucosinolate bioavailability by combining with myrosinase-activating foods (mustard, rocket). Oven-roasted broccoli (200 °C, 20 min) develops nutty flavours via the Maillard reaction and works well as a snack.
Broccoli as a regular component of a plant-rich diet delivers lutein and zeaxanthin (carotenoids, important for macular health), beta-carotene (vitamin A precursor), vitamin K (important for blood clotting and bone metabolism), and calcium and iron in amounts notable for a vegetable. PFAF lists broccoli as a food source of high nutritional significance. Regular consumption of cruciferous vegetables features in nutritional epidemiology studies on chronic disease — however without an authorised EFSA health claim at this level.
Broccoli stems and leaves are just as edible as the florets and are fully utilised in zero-waste cooking. Stems (peeled) contain similar nutrients to the florets but have a firmer texture, suitable for soups, stir-fries, or raw veggie sticks. Leaves can be steamed like Swiss chard or kale. Full utilisation corresponds to circular economy principles in nutrition and increases dietary fibre and vitamin intake.
Broccoli is a safe and very nutritious vegetable for most people. Large raw quantities can cause bloating and gastrointestinal discomfort in sensitive individuals — caused by glucosinolates and dietary fibre. Glucosinolates (especially goitrin, formed from gluconapin) have goitrogenic potential: very high regular intake (several portions daily) may impair iodine uptake by the thyroid in the presence of concurrent iodine deficiency. With known thyroid disorders (hypothyroidism, Hashimoto's) or ongoing thyroid hormone therapy: consult your doctor. Vitamin K is important for blood coagulation — individuals on vitamin K antagonists (warfarin, phenprocoumon) should keep broccoli intake consistent and discuss with their treating physician.
Broccoli is safe and recommended in usual dietary amounts during pregnancy — high folate content (63 µg/100 g) supports normal neural tube formation. Very large raw quantities should be avoided due to possible bloating. No contraindication known.
Safe in usual dietary amounts. Some breastfed infants may respond to high cruciferous vegetable intake in the mother's diet with colic or bloating — if noticed, reduce quantity and observe.
Broccoli is suitable for children from the start of solid foods (around 6 months) — cooked and pureed or as soft pieces for finger food. Raw only suitable for older children who can chew well. Toddlers can benefit from the nutrients (vitamin C, folate, calcium).
Drug interactions
Vitamin-K-Antagonisten (Warfarin, Phenprocoumon, Acenocoumarol)
Broccoli contains substantial amounts of vitamin K1 (~102 µg/100 g, USDA). Vitamin K antagonises the anticoagulant effect of coumarins. Sudden fluctuations in broccoli or cruciferous vegetable intake can destabilise INR values (coagulation parameter). Recommendation: keep daily broccoli quantity consistent and discuss with doctor/pharmacist.
Schilddrüsenhormone (Levothyroxin, Liothyronin)
Goitrogenic glucosinolates (goitrin from gluconapin) can theoretically reduce thyroid iodine uptake and increase thyroxine requirements in pre-existing hypothyroidism when very high raw broccoli amounts (> 500 g daily) are consumed. No relevant risk at therapeutic dosing and normal dietary intake; consistent consumption recommended.
Contraindications
- No absolute contraindications known for normal dietary amounts.
- Known allergy to Brassicaceae (cruciferous vegetables) — rare but possible. Symptoms: oral allergy syndrome, skin reactions.
Harvested part: flower head
- Time of day:
- Harvest in the early morning or forenoon while temperatures are still cool — florets are firmer then and keep fresh longer.
- Drying:
- HARVEST OF CENTRAL HEAD: Harvest the main flower head (central head) when the florets are still closed and compact (dark green, no open flowers) — once florets open and turn yellow they are overripe. Cut with a sharp knife approximately 15–20 cm below the head. After cutting the central head the plant begins forming side shoots — harvest these regularly while still compact. Freshly harvested broccoli keeps in the refrigerator for approximately 3–5 days, best wrapped slightly moist. Blanching and freezing is possible (approximately 12 months shelf life). NOTE: Broccoli is NOT dried — preparation is always fresh or frozen.
- Storage:
- 1 months — In the refrigerator (2–4 °C), loosely wrapped in moist kitchen paper or beeswax wrap. Not in airtight packaging — Brassica vegetables off-gas and need some air circulation. Frozen (after blanching 2–3 minutes in boiling water) up to 12 months.
- Time of day:
- Sprouts can be grown indoors year-round — no seasonal dependency as it is purely indoor cultivation.
- Drying:
- BROCCOLI SPROUTS (INDOOR GROWING): Use organic broccoli seeds (specifically labelled for sprouting, no fungicide treatment) in a sprouting jar or on moist cloth. Soak seeds 6–8 hours in lukewarm water, drain. Store jar at an angle (90°), rinse 2–3× daily with lukewarm water and allow to drain. After 3–4 days at room temperature (18–22 °C), in darkness or semi-shade, sprouts germinate. Then place 6–12 hours in indirect light to turn green (chlorophyll formation). Consume immediately or refrigerate up to 3 days. Do NOT dry — sulforaphane content drops sharply with heat.
- Storage:
- Fresh sprouts in the refrigerator up to 3 days. Do not freeze — lose texture and sulforaphane potential.
- Glucoraphanin (4-Methylsulfinylbutyl-glucosinolat)GlycosideContent: 0,4–1,2 % (Trockengewicht)Flower
Lead glucosinolate of broccoli and quantitatively most important in the florets. Hydrolysed to the isothiocyanate sulforaphane by the enzyme myrosinase (activated upon cell disruption by chewing or grinding). 10- to 100-fold more concentrated in broccoli sprouts than in mature broccoli. Sulforaphane is intensively researched as an Nrf2 activator and inducer of phase II detoxification enzymes.
- Sulforaphan (Isothiocyanat, Metabolit aus Glucoraphanin)OtherContent: variabel, abhängig von Myrosinase-AktivitätFlower
Bioactive metabolite formed only upon myrosinase cleavage of glucoraphanin. Activates the Nrf2/ARE signalling pathway and induces antioxidant and cytoprotective enzymes (e.g. glutathione S-transferase, haem oxygenase-1). Clinical studies demonstrate measurable sulforaphane plasma levels after broccoli consumption. Heat-sensitive: cooking above 60 °C inactivates myrosinase and strongly reduces sulforaphane yield.
- Vitamin C (Ascorbinsäure)VitaminContent: ~89 mg/100 g Frischgewicht (USDA)Flower
Broccoli is among the most vitamin C-rich vegetables — 100 g raw covers approximately 99 % of the EU daily reference intake (90 mg/day). Water-soluble and heat-sensitive: boiling reduces content by 30–50 %; steaming largely preserves it.
- Vitamin K1 (Phylloquinon)VitaminContent: ~102 µg/100 g Frischgewicht (USDA)Flower
Broccoli is among the highest vitamin K vegetables. Important for blood coagulation (clotting factors II, VII, IX, X) and bone metabolism (osteocalcin activation). Relevant for individuals on vitamin K antagonists (INR interaction).
- Folsäure (Vitamin B9, Folat)VitaminContent: ~63 µg/100 g Frischgewicht (USDA)Flower
Important for cell division, DNA synthesis, and neural tube formation during pregnancy. 100 g broccoli covers approximately 32 % of the EU daily reference intake (200 µg/day). Heat-sensitive: boiling reduces folate content; steaming preserves it better.
- Carotinoide (Lutein, Zeaxanthin, Beta-Carotin)OtherContent: Lutein+Zeaxanthin ~1403 µg/100 g; Beta-Carotin ~361 µg/100 g (USDA)Flower
Lutein and zeaxanthin accumulate in the macula of the eye and protect against oxidative light damage there. Beta-carotene is provitamin A (precursor to retinol). All three carotenoids are fat-soluble — absorption improves substantially when consumed with fat (e.g. olive oil).
- Ballaststoffe (Dietary Fibre, überwiegend unlöslich)PolysaccharideContent: ~2,6 g/100 g Frischgewicht (USDA)Whole plant
Broccoli provides a good proportion of insoluble dietary fibre (cellulose, hemicellulose) and smaller amounts of soluble fibre. Dietary fibre promotes intestinal peristalsis, contributes to satiety, and serves as substrate for the gut microbiome. High raw intake can temporarily cause bloating in those unaccustomed to it.
- Indol-3-Carbinol und Indole (weitere Glucosinolat-Metabolite)OtherContent: variabel (< 0,1 %)Flower
Alongside sulforaphane, glucosinolate breakdown (e.g. from glucobrassicin) also produces indole-3-carbinol (I3C) and its condensation product diindolylmethane (DIM). These compounds are investigated for their role in oestrogen metabolism and antioxidant mechanisms. Clinical evidence is still accumulating — no authorised EFSA health claims.
- [1]MonographUSDA FoodData Central — Broccoli, raw (FDC ID 170379)(accessed: 2026-05-21)
- [2]MonographFahey JW, Zhang Y, Talalay P (1997) — Broccoli sprouts: An exceptionally rich source of inducers of enzymes that protect against chemical carcinogens. PNAS 94(19):10367–10372. DOI: 10.1073/pnas.94.19.10367(accessed: 2026-05-21)
- [3]MonographFahey JW, Talalay P (2002) — Antioxidant functions of sulforaphane: A potent inducer of Phase II detoxication enzymes. Food and Chemical Toxicology 37(9–10):973–979. DOI: 10.1016/S0278-6915(99)00082-4(accessed: 2026-05-21)
- [4]MonographPlants For A Future (PFAF) — Brassica oleracea italica database entry(accessed: 2026-05-21)
- [7]MonographCliniTox Giftpflanzen — Brassica oleracea L.: schwach giftig (+) (Institut für Veterinärpharmakologie und -toxikologie, Universität Zürich)(accessed: 2026-08-10)
- [5]WikipediaBrokkoli (Wikipedia DE)(accessed: 2026-05-21)
- [6]WikipediaBroccoli (Wikipedia EN)(accessed: 2026-05-21)
🤝 Permaculture Partners
In your garden, this plant acts as:
✨ Best symbiotic partners
- 🌿 Onion Onion deters cabbage root fly.
- 🌿 Apium graveolens Classic companion-planting partner.
- 🌿 Lettuce Classic companion-planting partner.
- 🌿 Thymus vulgaris Thyme scent masks broccoli from cabbage white butterfly.
⚠️ Better not planted together
- 🥬 Fragaria vesca Classic companion-planting partner.
- 🥬 Tomato Classic companion-planting partner.
Source: Gertrud Franck, Gesunder Garten durch Mischkultur (1980, eigene Kuration) | Helga und Margarete Langerhorst, Mein gesunder Naturgarten (eigene Kuration)