The Super-Veggies: Cruciferous Vegetables
Cruciferous vegetables have it all: vitamins, fiber, and disease-fighting phytochemicals. Here's how to get more of them.
By Elaine Magee, MPH, RD
WebMD Weight Loss Clinic - Feature
Reviewed by Louise Chang, MD
What do broccoli, cauliflower, Brussels sprouts, kale, cabbage, and bok choy have in common? They're all members of the cruciferous, or cabbage, family of vegetables. And they all contain phytochemicals, vitamins and minerals, and fiber that are important to your health (although some have more than others.)
In fact, health agencies recommend that we eat several servings per week of cruciferous vegetables -- and for good reason.
Lower Cancer Risk?
One of the big reasons to eat plenty of cruciferous vegetables is that they may help to lower your risk of getting cancer.
A review of research published in the October 1996 issue of the Journal of the American Dietetic Association showed that 70% or more of the studies found a link between cruciferous vegetables and protection against cancer.
Various components in cruciferous vegetables have been linked to lower cancer risks. Some have shown the ability to stop the growth of cancer cells for tumors in the breast, uterine lining (endometrium), lung, colon, liver, and cervix, according to the American Institute for Cancer Research. And studies that track the diets of people over time have found that diets high in cruciferous vegetables are linked to lower rates of prostate cancer.
Lab studies show that one of the phytochemicals found in cruciferous vegetables - sulforaphane - can stimulate enzymes in the body that detoxify carcinogens before they damage cells, says Matthew Wallig, DVM, PhD. Through different mechanisms, two other compounds found in cruciferous vegetables -- indole 3-carbinol and crambene -- are also suspected of activating detoxification enzymes.
Further, research suggests there is some important synergy between the various compounds in cruciferous vegetables. Wallig, professor of comparative pathology at the University of Illinois at Urbana-Champaign, discovered that crambene is more active when combined with indole 3-carbinol.
Another way cruciferous vegetables may help to protect against cancer is by reducing oxidative stress. Oxidative stress is the overload of harmful molecules called oxygen-free radicals, which are generated by the body. Reducing these free radicals may reduce the risk of colon, lung, prostate, breast, and other cancers.
In a study funded by the National Cancer Institute, 20 participants were encouraged to eat 1 to 2 cups of cruciferous vegetables a day. After three weeks, the amount of oxidative stress in their body was measured. Then, after a three-week wash-out period, the study participants were told to take a multivitamin with fiber. Again, the oxidative stress was measured three weeks later.
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And the results? Oxidative stress in the subjects' bodies dropped 22% during the period when they were eating lots of cruciferous vegetables. But the change during the multivitamin segment was negligible (0.2%), says lead researcher Jay H. Fowke, PhD, an assistant professor and cancer epidemiologist for the Department of Medicine at Vanderbilt Medical Center in Nashville, Tenn.
More study is needed, but Fowke feels the evidence is pretty strong that eating cruciferous vegetables is a particularly healthful choice.
"There's no harm to it and consistently, across the line, it's associated with improved health and a reduced risk of various chronic diseases," he says in an email interview.
It's best, he says, to eat these veggies raw or only lightly steamed to retain the phytochemicals that make cruciferous vegetables special in terms of health.
Diets rich in fish and vegetables (including cruciferous and dark-yellow veggies) may also help to protect against cardiovascular disease. A recent study found that such a diet was linked to lower levels of markers of inflammation in the body. These markers may signal an increased risk of cardiovascular disease.
In another recent study, diets low in cruciferous and yellow vegetables, wine, and coffee but high in sugar-sweetened soft drinks, refined grains, and processed meat were identified as possibly increasing chronic inflammation and raising the risk of type 2 diabetes.
Comparison of Cruciferous Vegetables
Which cruciferous vegetables have the most vitamin A, vitamin C, and folic acid? The answers are:
- Kale (vitamin A)
- Broccoli (vitamin C)
- Brussels sprouts and broccoli (tied for folic acid)
Brussels sprouts have the most vitamin E (about 9% of the Daily Value) and vitamin B-1 (15% Daily Value). And it's broccoli and Brussels sprouts again that have the most healthy plant omega-3s: A cup of broccoli contributes about 200 milligrams, and a cup of Brussels sprouts about 260 milligrams.
Here's a comparison table of cruciferous vegetables, including the nutrients for which they contribute at least 10% of the Daily Value. Keep in mind that about half of the fiber in cruciferous vegetables is super-healthy soluble fiber.
|Per 1 cup:||Broccoli||Cauliflower||Cabbage||B. Sprouts||Bok Choy||Kale|
|Vitamin A||33% DV||1%||2%||16%||62%||137%|
|Omega-3s||200 mg||140 mg||60 mg||260 mg||100 mg||100 mg|
Tips for Enjoying Cruciferous Vegetables
To maximize taste and nutrition, here are some tips for buying and cooking cruciferous vegetables:
- Don't overcook cruciferous vegetables. They can produce a strong sulfur odor and become unappealing.
- You can buy several types of cruciferous vegetables ready-to-go in the frozen or fresh packaged sections of your supermarket, including broccoli, cauliflower, and Brussels sprouts.
- No raw veggie platter is complete without dark green broccoli or snowy white cauliflower florets.
- Add raw broccoli or cauliflower florets to your green salad to give the nutrients a big boost.
- Add chopped cruciferous veggies to soups, stews, and casseroles.
- When buying fresh broccoli, look for firm florets with a purple, dark green, or bluish hue on the top. They're likely to contain more beta-carotene and vitamin C than florets with lighter green tops. If it has yellow in it or is limp and bendable, the broccoli is old -- don't buy it.
Cruciferous Vegetable Recipes
Here are two simple side dish recipes featuring cruciferous vegetables.
Brussels Sprouts Sauteed with Pecans and Shallots
WebMD Weight Loss Clinic members: Journal as 1 cup "vegetables with 1 tsp fat"
I kept it light by using just a little canola oil, plus crisp turkey bacon to make the little crumbles that top off this dish. I love that this dish is easy to throw together, but looks elegant on a holiday or celebration table.8 cups Brussels sprout halves (trim off end of each sprout and cut in half)
4 strips Louis Rich turkey bacon (or similar)
1 tablespoon canola oil
1 cup sliced shallots
1 teaspoon minced garlic
3/4 cup pecan pieces, lightly toasted in a nonstick frying pan
2 teaspoons brown sugar
- Micro-steam the Brussels sprouts with a couple tablespoons of water until just barely tender (about 6 minutes, depending on your microwave). Watch carefully so they don't overcook. Drain any excess water.
- Meanwhile, cook the turkey bacon strips over medium-high heat in a large nonstick frying pan coated with canola cooking spray, flipping them often, until crisp. Let cool on a paper towel, and then break them into small pieces.
- Add the canola oil to the same pan and heat over a medium-high flame. Add the shallots and saute, stirring frequently, for a couple of minutes. Add the minced garlic and saute another minute or two or until the shallots are golden. Stir in the Brussels sprout halves and saute a couple of minutes, stirring occasionally, to char part of the sprouts.
- Sprinkle pecans and brown sugar over the top and stir to blend. Reduce heat to medium-low and continue to cook and stir for another minute. Add salt and pepper to taste, if desired. Spoon the mixture into a serving bowl and sprinkle turkey bacon bits over the top.
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Yield: 8 servings
Per serving: 165 calories, 6 g protein, 20 g carbohydrate, 9 g fat (0.9 g saturated fat, 5.2 g monounsaturated fat, 3 g polyunsaturated fat), 6 mg cholesterol, 5 g fiber, 110 mg sodium. Calories from fat: 49%.
Broccoli With 3-Minute Lemon Sauce
WebMD Weight Loss Clinic members: Journal as 1 cup of vegetables without added fat
This lemon sauce has a lot of flavor, so you only need a little drizzle to dress up your broccoli florets.6 cups raw broccoli florets, rinsed well
2 tablespoons lemon curd (available in jars)
2 tablespoons fat-free half-and-half
Freshly ground pepper to taste
- Add the broccoli and 1/4 cup water to a microwave vegetable steamer container and cook on HIGH until broccoli is just tender and still bright green (about 3 minutes, depending on the microwave).
- Meanwhile, add lemon curd and fat-free half-and-half to a small, nonstick saucepan and cook over low heat, stirring often, until blended and hot. Add pepper to taste, if desired.
- Drizzle sauce over broccoli and serve.
Yield: 6 servings
Per serving: 57 calories, 3 g protein, 9 g carbohydrate, 1 g fat, 0.4 g saturated fat, 7 mg cholesterol, 3 g fiber, 34 mg sodium. Calories from fat: 17%.
Recipes provided by Elaine Magee; © 2007 Elaine Magee
Published April 20, 2007.
SOURCES: Fowke J.H., et al, Carcinogenesis, 2006; 27:10; pp 2096-2102. Wallig, M., et al. Journal of Nutrition, 2005;135(12S):2972S-7S. Steinmetz, K.A., and Potter, J.D., Journal of the American Dietetic Association, Oct. 1996; 96:10 pp 1027-1039. American Institute for Cancer Research: "Foods That Fight Cancer-Cruciferous Vegetables." Cohen J.H., et al, Journal of the National Cancer Institute, 2000 92:61-8. Nettleton, J.A., et al., American Journal of Clinical Nutrition, June 2006; 83:6, pp 1369-1379. Schulze, M.B., et al., American Journal of Clinical Nutrition, Sept. 2005 Vol. 82, No. 3, pp 675-684. American Institute for Cancer Research website: Cruciferous Vegetables. AICR Newsletter, Spring 2007, Issue 95. Matthew Wallig, DVM, PhD, professor of comparative pathology, University of Illinois at Urbana-Champaign (email interview). Jay H. Fowke, PhD, assistant professor, cancer epidemiologist, Department of Medicine, Vanderbilt Medical Center, Nashville, Tenn.
©2007 WebMD Inc. All rights reserved.
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