Leafy greens are the superstars of the vegetable brigade. Kale, widely considered the reigning king, is unusually high in calcium, magnesium and vitamin K…and, like other greens, is loaded with disease-fighting phytochemicals, such as lutein and vitamin C.
But let’s be honest—kale’s somewhat bitter taste isn’t for everyone…and even if you love this veggie, you’re probably not going to eat it every day. What other disease-fighting greens do you need in your diet?
Basic nutrition is just one reason that experts advise Americans to eat at least five servings of greens and other vegetables daily. But if you’re concerned about specific medical conditions, research has shown that some leafy greens are particularly effective. For example…
• Arugula and cancer. Arugula is a peppery green with a sharp taste that adds a distinctive zip to otherwise bland salads. The pungent flavor has earned it the nickname “salad rocket.”
The zesty flavor of arugula is largely due to its high concentration of sulfur-containing compounds. We think of arugula as a salad green, but it’s actually a crucifer—in the same plant family as superfoods such as broccoli, cabbage and kale. Like other crucifers, it contains a group of anticancer compounds known as glucosinolates, which have detoxifying effects.
How arugula helps: Compounds in arugula, including sulforaphane and indole-3-carbinol, increase the body’s excretion of a form of estrogen that has been linked to breast cancer. A Chinese study found that women who regularly ate a daily serving of cruciferous vegetables were 50% less likely to develop breast cancer. Another study found that just one weekly serving was enough to reduce cancer risk (including oral, colorectal and kidney malignancies).
Bonus: The sulforaphane in arugula has another benefit. It appears to help the body eliminate H. pylori, a bacterium that causes most peptic ulcers and greatly increases the risk for gastric cancer.
• Spinach and macular degeneration. As the US population ages, there’s been a dramatic increase in age-related macular degeneration, a leading cause of blindness. Could a few weekly servings of spinach make a difference? There’s good evidence that it might.
How spinach helps: Spinach is exceptionally high in lutein, a plant pigment that concentrates in the eyes and deflects damaging light from sunshine. Studies have found that people who consumed 6 mg of lutein daily—the amount in about one-half cup of cooked spinach—were 43% less likely to develop macular degeneration. Research published in JAMA Ophthalmology shows that people who consume generous amounts of lutein are also less likely to develop cataracts than those who eat less.
Important: Whether you prefer your spinach raw or cooked, be sure to have it with a little bit of oil or fat—a drizzle of olive oil is plenty—or a small amount of some other fat such as chopped nuts or avocado. Lutein is a fat-soluble nutrient, which means it is absorbed more efficiently when it’s consumed with a little fat.
• Parsley and UTIs. Most people think of parsley as a colorful garnish—pretty to look at, but not much of a food. But around the world, parsley is found in tabbouleh, pesto (with or without basil) and other fragrant dishes…and it’s a good green to eat if you get frequent urinary tract infections (UTIs).
About half of all women will eventually get a UTI…men get them, too, but less often. Patients with recurrent UTIs (defined as two separate infections within six months or three within one year) often depend on antibiotics—and resign themselves to the likely side effects of these drugs, such as diarrhea.
How parsley helps: It contains apigenin, a compound that acts as a diuretic and also has anti–inflammatory effects. According to a report in the journal Case Reports in Medicine, women who combined parsley with other herbal treatments (such as garlic) had an impressive decrease in urinary frequency and other symptoms—by 80%, in one case. Parsley’s UTI–fighting effect is presumably because of apigenin’s diuretic effect.
Another benefit: Reduced risk for cancer. Chlorophyll and other compounds in parsley have anti-cancer effects—including the ability to help inhibit the cancer-causing effects of fried foods.
Since parsley is so concentrated in nutrition and phytochemicals, just a few sprigs (or about one-quarter cup) consumed whenever possible provides exceptional health benefits. Chopped parsley can be added to salads, sauces, soups and grilled fish.
• Kale and osteoporosis. Kale’s reputation as the king of veggies is based, in part, on its ability to promote bone health. People often think that milk is a great calcium source, but the absorption of calcium from kale and other leafy greens is actually higher—between 40% to 64%, compared with about 32% from milk.
And that’s not all. In addition to being rich in calcium, kale also is an excellent source of vitamin K, a critical nutrient that helps anchor calcium into bone. One cup of raw kale supplies more than 600% of the recommended daily vitamin K intake. If you’re concerned about bone health, you should definitely make an effort to eat more kale.
Another benefit: Improved heart health. Kale and other greens, as well as beets and celery, have been found to improve blood pressure and blood flow. While a high intake of fruit and vegetables is associated with healthy blood pressure and reduces risk for heart disease and stroke, kale and cruciferous vegetables are linked to even greater protection. A good goal: Three to four servings of kale and other greens a week.
Important caveat: In normal amounts, kale is among the healthiest foods you can eat. But some people go overboard. Too much kale, like other cruciferous vegetables, can cause flatulence (gas) for many people. Eating too much raw kale (for example, more than three servings a week) can also interfere with the production of thyroid hormone, leading to the formation of a goiter. And because kale is such a rich source of vitamin K, anyone taking warfarin (Coumadin), an important anticlotting drug that interacts with this vitamin, should consult a doctor before eating kale or any leafy greens.
Click here to buy Dr. Murray’s book, Bottom Line’s Encyclopedia of Healing Foods.