Broccoli is a nutrition champion. Like other cruciferous vegetables in the Brassicaceae family, it’s rich in vitamin C, folate (a B vitamin) and fiber, plus it has potassium, vitamin K and beta carotene. One cup (3 ounces, raw, chopped) has about as much vitamin C as a medium-sized orange. And all for only 30 calories per cup.
Studies have linked cruciferous vegetables to a reduced risk of bladder, colon, lung and other cancers and have attributed this to their unique phytochemicals. Most recently, an analysis of 13 existing studies from the U.S., Europe, and China, published in the journal The Breast, linked broccoli and other cruciferous vegetables to a 15 percent reduced risk of breast cancer in postmenopausal women.
Broccoli (derived from the Latin word meaning arm or branch) is an especially good source of sulforaphane, which is formed from another compound, glucosinolate, when the vegetable is cut, chopped, chewed and digested. According to test-tube studies, sulforaphane may inhibit cancer, in part, by boosting production of enzymes that detoxify carcinogens and inhibiting other enzymes that activate carcinogens. In addition, phytochemicals in broccoli may reduce the spread of cancer cells or cause them to self-destruct.
Broccoli sprouts, the edible young shoots from broccoli seeds, are even richer in sulforaphane, ounce for ounce. Two small studies suggested that eating them along with broccoli will boost sulforaphane absorption more than eating either food alone. On the other hand, broccoli sprouts have lower levels of other potential anti-cancer compounds, and they lack the full range of nutrients and fiber found in broccoli.
Not everyone is a broccoli fan, though, and genes may play a role. Researchers have discovered that people who have two copies of a certain gene are very sensitive to the bitter taste of glucosinolate-containing vegetables. (This may have some evolutionary implications since such taste receptor genes may have helped early humans avoid toxic plants, which are often bitter.) One way around that, as a 2011 study in young children found, is to mask broccoli by dipping it in a light salad dressing.
How to handle it
Look for fresh broccoli with tight florets that are dark green or purplish, not yellow. All parts, even the leaves, are worth eating. Ounce for ounce, broccoli florets have more beta carotene and sulforaphane than the stalks, but the stalks have more fiber. Frozen broccoli is also very nutritious, but watch out for products with high-calorie, salty sauces.
Whether it’s better to eat broccoli raw or cooked is a toss-up. A 2005 study found that raw broccoli raised blood levels of sulforaphane more than cooked. But a minimal amount of cooking is needed to break down the plant’s cell walls, making antioxidants, such as carotenoids, more available. The key to getting the most nutrients and phytochemicals is to not overcook broccoli (as in boiling until mushy). It should still be bright green and crunchy, not dull green and flaccid. Try light steaming (in as little water as possible), quick stir-frying or microwaving. Overcooking also intensifies the sulfur smell.
Even people who are not fond of broccoli may like broccoli sprouts because they are milder in flavor. You can add them to sandwiches and salads.
Adding wasabi, mustard, radish or other foods that contain sulforaphane to your broccoli recipes not only adds more of a bite—if you like that—but may also boost the potential benefits.
Broccoli can cause gas and bloating in some people, such as those with irritable bowel sydrome. The culprit is a complex sugar called raffinose, which bacteria in the large intestine feed on, releasing gas. If you don’t tolerate broccoli well, try eating smaller portions more often, or try an enzyme product (such as Beano or its generics) that helps break down the sugar so it’s more digestible.
Stalking more broccoli
If you like broccoli, you’ll probably like the following, too. You can steam or stir-fry all of them. You can also add them to pasta, soups, stews and other dishes.
Broccolini: This cross between broccoli and Chinese kale comes in a bunch of long slender stalks with small buds and tastes like asparagus.
Broccoli rabe: Also called rapini, this comes in a bunch with thin stems, many leaves and small flowers and has a bitter but interesting flavor, like some leafy greens.
Broccoflower: A cross between broccoli and cauliflower, this comes in a solid head like cauliflower but is green, not white. It is good raw as a dipping vegetable.
Beneforté: Developed by scientists who crossbred traditional British broccoli with wild Sicilian broccoli, this “super” broccoli has two to three times more glucoraphanin (a glucosinolate that converts to sulforaphane) than regular broccoli. It’s now available nationwide at Sam’s Club, as well as in some retail stores in several states.
Bottom Line: Broccoli has the sulforaphane advantage, but you can’t go wrong with any cruciferous vegetables, including cauliflower, Brussels sprouts, cabbage, bok choy and kale. Try to eat them at least once or twice a week for good health. And if you don’t like them plain, go ahead and dip them in a healthy dressing, just as kids like to do.
Published February 19, 2013