Cruciferous vegetables, or brassica vegetables, are an antioxidant group of vegetables that are extremely high in vitamin A carotenoids, vitamin C, folic acid, and fibre. The vitamin K content of cruciferous vegetables, especially kale and collards, helps regulate inflammatory response, including chronic responses that can increase the risk of certain types of cancer. Additionally, the phytonutrients in brassica vegetables, glucosinolates, have been shown to lower the risk of certain cancers.
Chopping or chewing breaks down glucosinolates to isothiocyanates and other antioxidant compounds that contain sulfur. These sulfurous compounds have the ability to stop the growth of cancers of the uterus, breast and cervix.
The health benefits, very low glycemic index and low calorie count make this group of vegetables incredibly nutrient-dense, high-net gain and alkaline-forming. In other words, they give you a big bang for your buck. Most people can identify broccoli, cabbage, cauliflower and Brussels sprouts, but this family actually includes a wide variety of produce:
- Bok choy
- Brussels sprouts
- Chinese cabbage
- Collard greens
- Daikon radish
- Land cress
- Mustard greens
- Shepherd’s purse
Studies have shown raw cruciferous vegetables, especially eaten within 48 hours of being picked, have the highest enzymatic activity. This means the nutrients are more likely to be absorbed in the upper digestive tract and made available to other tissues in the body.
When eating brassica vegetables cooked, it is better to chop them raw and let them sit for a few minutes before cooking to increase enzyme availability. This allows certain enzymes to go to work before they become deactivated by cooking. There are some benefits to eating these vegetables cooked, even if the enzymes are deactivated. The digestive products are absorbed in the colon instead of the upper digestive tract, which is linked to a risk reduction in colon cancer. Additionally, raw vegetables eaten in too much quantity can be harder for some people to chew and digest which can lead to bloating and gas.
If you do choose to cook cruciferous vegetables, lightly steaming them is the best option for conserving nutrients. As a bonus, you can actually save the water you steamed the vegetables in and use it when cooking grains, add it to homemade broth or sauces, drink it straight or water your plants with it. There will be nutrients in the water (you can tell by the colour the water changes the longer you steam for) and it’s a great way to reduce waste. Baked vegetables are also nutritionally sound.
Include cruciferous vegetables in your diet a minimum of 2-3 times per week, and make the serving size at least 1-1/2 cups. For better health, increase consumption to 4-5 times per week and make the serving size 2 cups.
Haas, Elson M., Staying Healthy with Nutrition. 2006. New York, NY. Ten Speed Press.