“Dark leafy greens offer a lot of immune-boosting nutrients, such as zinc and vitamins A, C and E, which may also help reduce the risk of certain forms of cancer,” says Leslie Beck, a registered dietitian in Toronto and author of Foods That Fight Disease.
They also contain high amounts of vitamin K, a nutrient essential for bone health and now, possibly, cancer prevention. In a recent study, researchers at the Mayo Clinic found that study participants who got high amounts of vitamin K from their diets were 45 per cent less likely to develop non-Hodgkin’s lymphoma compared to participants who consumed little vitamin K.
The hefty anti-cancer punch comes from the phytochemicals in cruciferous vegetables, which include dark greens like broccoli, kale, watercress, arugula and collard greens. “One compound, called sulforaphane, may possess potent anti-cancer activity,” says Andrew Weil, founder and director of the Arizona Center for Integrative Medicine at the University of Arizona.
Another recent study suggests that indole-3-carbinol (I3C), a substance in these leafy greens, may also help battle breast cancer. Researchers at the Ohio State University Comprehensive Cancer Center tested I3C on a molecule that’s responsible for cell division and proliferation. I3C destroyed the offending molecule to prevent the growth of breast cancer.
A new study suggests that dark leafy greens may help lower the risk of type 2 diabetes. Researchers at the University of Leicester in England found that increasing consumption by 1.15 servings a day decreased incidence by 14 percent.
Carrots aren’t the only vegetables that are good for the health of your eyes. “Dark greens are a good source of the carotenoids lutein and zeaxanthin, compounds that help prevent eye disorders such as age-related macular degeneration and cataract formation,” says Weil.
Pick the Best Bunch
A few pointers to help you bring home the freshest and healthiest leafy greens
1. Look for brightly-coloured leaves and firm stalks.
2. Choose bunches with smaller leaves — they’re more tender and milder in taste than bigger leaves.
3. Opt for locally grown, organic varieties whenever you can.
Does it really do the body good? Chlorophyll provides greens with their brilliant colour, nourishment and energy. Elson M. Haas suggests in his book Staying Healthy with Nutrition that it may also detoxify the liver and help heal body tissues. But not everyone agrees. “It’s very important to plants, but has no function in the human body and no role in human nutrition, except possibly as a source of magnesium,” says Weil. (Magnesium sits smack in the middle of the chlorophyll molecule.) Tip: If you find water bland, improve the taste with a few drops of liquid mint-flavoured chlorophyll, available at most health food stores.
For more on the health benefits of leafy greens, check out this article on the five you should include in your diet.