November 2013 update: Please read the groundbreaking news about crucifers!
Along with vegetables from the Allium family, cruciferous ones TOP the list of foods that fight cancer: Broccoli sprouts and broccoli, Brussels sprouts, cauliflower, cabbage, kale, collards, mustard greens, arugula, watercress, rutabaga and radishes.
Crucifers contain loads of glucosinolates, chemical compounds that release two other classes of compounds with extremely high anti-cancer activity—isothiocyanates and indoles.
For those of you with estrogen-dependent cancers, indoles are essential. They “seem capable of causing modifications in the structure of estradiol that reduce the hormone’s ability to promote cell growth… .” (Dr. Richard Beliveau, in his book “Foods that Fight Cancer”) Indoles are abundant in broccoli and Brussels sprouts and are also sold as “DIM” supplements.
The other class of compounds include a glucosinolate called sulforaphane, which as its name suggests, contains sulphur, and seems to “greatly accelerate the body’s ability to flush out toxic substances linked to the development of cancer.” (Beliveau again.) Broccoli sprouts, he says, are the best source, often containing up to 100 times the levels of sulforaphanes found in the mature mother. (Look for them in your local health food store, or buy the seeds and grow them yourself.)
But there’s a catch to cooking your crucifers. Glucosinolates—and the enzymes they react with–are extremely sensitive.
• Don’t boil them. The glucosinolates will end up in the water.
• Microwave? The evidence is mixed. For sure, don’t microwave in lots of water, and keep your cooking time short. But why take a risk for the sake of a clean pot?
• Steaming veggies lightly (until bright green) is a good way to cook crucifers and may help retain glucosinolates. Use a small amount of water and a steamer so they don’t touch the liquid.
• Stir frying lightly may also help retain glucosinolates. Use a small amount of olive oil (not extra virgin as it smokes too easily) and low to medium heat.
•There are two big caveats here, according to UK scientist Dr. Paul Thornalley. You must cook or eat your raw crucifers soon after you cut them. If they sit around at room temp, they lose their cancer-fighting nutrients.
• And you musn’t shred them finely. According to Thornalley, shredding vegetables thinly exposes the beneficial nutrients to proteins that degrade them. (Thornalley’s study used 5 mm veggies that sat for 6 hours. Check out Thornalley’s update on shredding and juicing and other methods of prepping crucifers. )
What about all using those packages of pre-cut veggies you throw in the pan? Nope. They’ve been sitting around for who knows how long. Flash frozen veggies? Nope. The process apparently exposes the glucosinolates to damage from heat.
And how about eating fresh crucifers raw? According to Thornalley, that’s a great choice. Watercress, radishes and broccoli sprouts, for example, taste great in a salad. Dress them with some salsa or lemon juice and olive oil.
The bottom line: Chew your veggies well. Chomping releases the cancer- fighting nutrients. Plus, the better you grind up those sulphoraphanes, the better your chances of preventing any explosive aftereffects.