Broccoli is one of the most nutrient-dense foods you can eat. On the Aggregate Nutrient Density Index (ANDI), which scores foods from 1 to 1,000 based on nutrients per calorie, raw broccoli scores 376. That places it well above most vegetables and far above grains, meats, and dairy. A single cup of raw broccoli delivers more than a full day’s worth of vitamins C and K for just 35 calories.
What You Get in One Cup
One cup (90 grams) of raw broccoli contains 35 calories, 2.3 grams of protein, 5.6 grams of carbohydrates, 2.2 grams of fiber, and virtually no fat. That fiber alone covers about 8% of your daily value. You also get more than 100% of your daily vitamin C and vitamin K needs, plus meaningful amounts of vitamin A, folate, and manganese, each exceeding 10% of the daily value. For a food with so few calories, that ratio of nutrients to energy is hard to beat.
How Broccoli Compares to Other Vegetables
Broccoli consistently outperforms its close relatives. Cauliflower, for example, provides only about three-quarters of the vitamin C and 20% of the vitamin K you’d get from the same serving of broccoli. Cauliflower also contains very little vitamin A, while broccoli offers a solid amount. Both have similar fiber content (around 2 grams per cup), so the real gap is in vitamins and protective plant compounds. On the ANDI scale, cruciferous leafy greens like kale and watercress score at the top (1,000), but broccoli at 376 still ranks far above most whole foods people eat regularly.
Protective Compounds Beyond Vitamins
Broccoli’s nutrient density goes beyond standard vitamins and minerals. It contains a compound called glucoraphanin, which makes up about 50% of its total glucosinolates. When you chew or chop broccoli, an enzyme called myrosinase breaks glucoraphanin down into sulforaphane, a compound studied extensively for its role in supporting the body’s natural detoxification and antioxidant defenses.
The amount of glucoraphanin in mature broccoli ranges from 25 to 650 milligrams per 100 grams of fresh weight. Broccoli sprouts pack an even bigger punch: three-day-old sprouts contain roughly 10 to 100 times more sulforaphane precursors than the mature plant. If maximizing these protective compounds matters to you, adding broccoli sprouts to salads or sandwiches is a simple way to do it.
Cooking Methods That Preserve Nutrients
How you cook broccoli matters almost as much as eating it in the first place. A study published in the Journal of Zhejiang University tested five common cooking methods and found that steaming preserved the most nutrients across the board. Steamed broccoli retained nearly all of its vitamin C, while boiling destroyed about 33% and stir-frying followed by boiling wiped out 38%. Chlorophyll, the green pigment linked to several beneficial compounds, was almost unchanged after steaming but dropped 27% after boiling.
The differences are even more dramatic for glucosinolates, the precursors to sulforaphane. Steaming kept total aliphatic glucosinolate levels essentially unchanged, while microwaving destroyed 60%, stir-frying destroyed 55%, and boiling cut them by 41%. The reason steaming works so well is that it heats the broccoli enough to soften it without submerging it in water, which leaches water-soluble vitamins and compounds into the cooking liquid. Carotenoids, another group of beneficial pigments, also survived steaming, microwaving, and stir-frying well but dropped significantly with boiling.
There’s an important nuance with myrosinase, the enzyme responsible for creating sulforaphane. High heat inactivates it. Microwaving at high power for more than five minutes, for instance, denatures the enzyme so it can no longer convert glucoraphanin into sulforaphane. Light steaming (around three to four minutes, until bright green but still slightly firm) is the sweet spot: hot enough to improve digestibility, gentle enough to preserve the enzyme and the compounds it acts on.
One Thing to Know About Thyroid Health
Broccoli and other cruciferous vegetables contain compounds called thioglucosides, which your body metabolizes into thiocyanates. These can interfere with iodine uptake by the thyroid gland. For most people eating a varied diet with adequate iodine, this isn’t a concern. The effect becomes relevant primarily in people who already have low iodine intake and eat very large quantities of raw cruciferous vegetables. Cooking reduces the concentration of these compounds, so if you have a thyroid condition, lightly steaming your broccoli addresses both the goitrogen concern and the nutrient retention issue at the same time.