Power often runs in families. Powerful families have certainly played a role in shaping our world, for better or for worse, but one of the most powerful families in the world – and the one that can most directly influence your life – is not in the history books, but is found in gardens, produce sections and, hopefully, your kitchen. The family in question? It is the brassica (Brassicaceae) family, also known as the cruciferous vegetables. Most people recognize that veggies are good for us, but this family of vegetables packs a particularly powerful punch.
Why so powerful?
The brassica vegetables are rich in the usual suspects – vitamins, minerals, fiber, and antioxidants – but what makes this family really special are certain phytochemical compounds that are unique to the brassica family and exert powerful health benefits, including reducing the risk of certain cancers.
These vegetables – including broccoli and broccoli sprouts, all varieties of cabbage (red, green, napa, savoy), cauliflower, collards, kale, arugula, bok choy, kohlrabi, brussels sprouts, turnips, rutabagas, radishes (regular and daikon) – are rich in sulfur-containing compounds. These compounds are key players in our bodies’ natural detoxification processes, binding to numerous environmental toxins, neutralizing them and allowing for their excretion from the body. The body also uses these compounds to make glutathione, a potent antioxidant and powerful detoxification compound in its own right. The best known of these compounds are glucosinolates. When glucosinolates break down, they release sulfur-containing molecules, including isothiocyanates and indoles, which studies show may reduce the risk of certain cancers, including lung, stomach, breast, and colorectal cancers. This may be because of their influence on phase 1 and phase 2 liver detoxification, which then influences several processes related to the body’s ability to process carcinogens and protect DNA from their damaging effects.
Indole-3-carbinol (I3C) is one type of indole that has been well researched. I3C seems to be especially protective against hormone-dependent cancers such as breast, uterine, and even prostate cancer, by promoting healthy estrogen metabolism. Specifically it promotes the conversion of 2-hydroxyestrogen, the “good” estrogen that inhibits cancer development, while decreasing the conversion of 16-alpha-hydroxyestrogen, the “bad,” or cancer-promoting, estrogen. And like similar compounds found in these veggies it also helps to reduce free radicals which can cause DNA damage. It appears that stomach acid further converts I3C into other compounds: diindolymethane (DIM) and indole carbazole (ICZ). DIM has received a lot of attention in recent years and has been shown to induce apoptosis, or cell death, in human cancer cells. Both I3C and DIM are available in supplement form and have been studied as isolated compounds.
Cooking with Crucifers
You can benefit from the brassica veggies whether you eat them raw or cooked; the important thing is to just eat them! If you’re going to cook them there are a couple of techniques to consider. Since breaking the cell wall activates enzymes that convert the glucosinolates to the beneficial isothiocyanates and indoles, slicing, cutting, and/or chopping your brassica vegetables and allowing them to sit for five to ten minutes before cooking or eating allows time for this enzymatic activity, and may increase their health benefits. Vitamin C also enhances the activity of this enzymatic activity, so sprinkling a little lemon juice on the veggies may also be beneficial. As with any vegetable, cooking should be gentle and relatively quick. Sautéing, roasting, and steaming are probably your best bet – just enough to soften the texture but retain the bright color. For those who find this family of vegetables a little too, ahem, gas-producing, cooking will help to make them more digestible. Finally, don’t overlook the less popular part of these veggies such as the leaves and stems. I find the stem of the broccoli to be the most enjoyable part, just peel it first to make it more digestible. The same is true of turnip and kohlrabi greens – instead of throwing them out, try sautéing them like any other green or add them to soups.
Although overwhelmingly healthy, the brassica vegetables do contain compounds called goitrogens that certain people may be sensitive to. Goitrogens are goiter-causing substances that can interfere with thyroid function by blocking iodine availability and impairing thyroid hormone production. These compounds are most concerning to those who have a pre-existing thyroid condition and are generally not a concern for those with normally functioning thyroids. The best bet for those with pre-existing thyroid conditions is to limit intake of these foods to no more than one serving per day and to favor cooked brassica vegetables over raw, as cooking reduces this compound.
Next time you stroll down the produce aisle, add a few of the brassica veggies to your cart and aim to get at least two to three servings each day. With all of the health benefits they offer, this powerful family of vegetables certainly deserves a place on your plate.