Unassuming, quiet and easy to overlook, green leafy vegetables are the Clark Kent of the vegetable world. And just like Clark, these vegetables’ hidden abilities transform them into true superheroes, with the power to disarm disease and restore function to the body. As I’ve studied nutrition, health and disease prevention over the last 25 years, I keep coming back to the same simple fact: Vegetables are the foods that are most likely to help us prevent chronic disease. Epidemiology shows that the more produce humans include in their daily fare, the lower their risk for all sorts of diseases, especially the ailments that most plague the industrialized world: heart disease, diabetes, cancer, osteoporosis, obesity, stroke and dementia.
So what makes green vegetables so potent? There’s no simple answer to this question. Green vegetables are complex packages of health-promoting, disease-fighting compounds that lead to a thriving body. In fact, while our knowledge about nutrition continues to grow, there are still thousands of unidentified compounds in green vegetables, many of which likely make a significant impact on overall health. This is why focusing on real food, not only supplements, is critical to health. No supplement can offer the symphony of nutrients found in kale or Brussels sprouts. Even supplements made from dehydrated whole foods lack the element of fiber, which leads to weight and blood sugar stabilization, improved satiety, reduced inflammation through the alteration of gut bacteria and more.
Each year through Vibrance Nutrition, my fitness and nutrition consultancy, I host a 30-Day Greens Challenge for my clients. During the month, I email daily recipes, tips and encouragement to help participants consume their daily three cups of green vegetables. We also share feedback and ideas on a Facebook group. Each year, participants consistently report that the increase in greens provides more energy, better moods and improved digestion. They find by focusing their nutrition goals on this one single step — eating enough green vegetables every day — they see a significant improvement in their quality of life in just 30 days.
If I haven’t yet fully convinced you of the importance of these vegetables, let’s take a look at some of the science behind greens intake and various chronic ailments.
Greens and Heart Disease
Heart disease is the No. 1 killer of men and women in the United States, and eating greens is associated with a decreased risk of coronary heart disease. Many identified compounds in green leafy vegetables contribute to this risk reduction, including fiber, magnesium, potassium and multiple antioxidants. Certain types of soluble fibers can help reduce circulating cholesterol levels. These fibers bind bile acids in the digestive tract, forcing them out of the body and lowering the body’s supply. In turn, this forces the body to use cholesterol to make more bile acids, thus lowering circulating cholesterol levels. Fiber also feeds beneficial bacteria, crowding out pathogenic species that can contribute to systemic inflammation and subsequent cellular damage, which may lead to plaque deposits in the arteries. High dietary potassium and magnesium intake is also associated with lower blood pressure, and elevated blood pressure is an independent risk factor for heart disease.
Greens and Cancer
Thirty percent of all cancers are believed to be due to dietary choices. In 2013, these cancers accounted for about 175,000 deaths in the United States. Greens are a powerful ally in cancer prevention. A meta-analysis of 15 studies found women who consumed the most fruits and vegetables had the lowest risk of breast cancer. While this association was strongest in women who consumed lots of produce early in life and continued to do so throughout their lifespan, it’s never too late to start improving your diet. Green leafy vegetables are packed with carotenoids and other antioxidants that protect cells from the damage that can lead to cancer down the road. Many people think of orange-hued plants, such as carrots and winter squash, when they think of carotenoids. While these are excellent sources, this orange-colored compound is also highly available in leafy greens, including spinach and kale.
Cruciferous greens, such as collards, kale, bok choy and broccoli are rich in sulforaphane, a crucial nutrient to support the liver in detoxification. Sulforaphane intake is associated with reduced risk of many common cancers. A healthy liver can efficiently rid the body of excess estrogen, thereby reducing the risk of estrogen-based cancers. Sulforaphane and other phytochemicals (like those found in green tea) also fight cancer by increasing the expression of tumor-suppressor genes. Some research indicates sulforaphane and phenethyl isothiocyanate, another compound found in cruciferous vegetables, induce apoptosis (self-programmed cell death) and cell cycle arrest (a halting of proliferation) in several kinds of cancer cells.
Greens and Eye Health
Lutein — another carotenoid derived from both dark green, leafy vegetables and orange and yellow plants — helps form the macular pigment of the human eye. Moderate lutein intake is associated with decreased macular degeneration risk and less visual impairment. Lisa Holk, a naturopath and professor at the Pacific College of Oriental Medicine, says consuming 6 to 12 mg daily can help prevent cataracts and age-related macular degeneration. Large amounts of lutein are found in green vegetables, including broccoli, collard greens, kale and spinach, as well as eggs and orange-colored fruits and vegetables.
Greens and Bone Health
Vitamin K is needed for bone formation, and it contributes to positive calcium balance in the body. It’s richest in green leafy vegetables. In a study of postmenopausal Japanese women, vegetable intake was positively associated with bone mineral content. Postmenopausal women are at an increased risk of osteoporosis due to the drop in estrogen, so consuming a diet rich in green vegetables can help protect bone health later in life.
Greens and Your Brain
Two decades of research on nutrition and dementia indicate diet has a strong protective influence on brain and neuronal health. Polyphenols are a broad class of antioxidant compounds found in fruits and vegetables that demonstrate neuroprotective effects. Given the increasing evidence of free radicals and oxidative stress in the development of senile dementia, Parkinson’s disease and other neurodegenerative diseases, it makes sense that these compounds — with their powerful ability to calm inflammation and detain free radicals — would offer protection. Polyphenols are found in green tea as well as many culinary herbs, including oregano, rosemary, basil and thyme. Brussels sprouts, kale and spinach also contain high antioxidant levels and can protect the brain and body against oxidative stress. One study noted that senior adults who ate one to two servings a day of green leafy vegetables had the cognitive ability of a person 11 years younger than those who consumed none. This study found that vitamin K, lutein, folate and beta-carotene were most likely responsible for maintaining brain health; all of these nutrients are abundant in leafy greens.
As a group, greens share several valuable nutrients, including magnesium, vitamin K, folate and potassium. The crucifers, which include broccoli, kale, collard greens, bok choy, cabbage, arugula, cauliflower and Brussels sprouts, have many compounds that enhance detoxification and fight cancer. You’ll notice themes among the greens below, all of which are amazing nutritional superheroes.
1. Kale: This cruciferous vegetable deserves the nutritional star status it has gained in the past decade, thanks to its abundance of vitamin K, carotenoids and the cruciferous-specific compounds sulforaphane and glucosinolates. Kale is delicious raw in salads (if you wish, “massage” it first with a sprinkle of salt to break down its dense texture); oven-roasted as kale chips; sautéed with olive oil, lemon and garlic; or added to soups, stews, stir-fries or casseroles.
2. Dandelion: Dandelion stands out because it has a significant amount of calcium, making it a bone-building green that deserves a place at the table. It’s also high in lutein and other carotenoids. Cut the bitterness of dandelion by choosing small, young greens and drizzling a well-aged balsamic vinegar or lemon juice on sautéed leaves.
3. Chard: At least 13 polyphenol antioxidants have been identified in chard, offering blood-sugar-regulating, antioxidant, anti-inflammatory and detoxification support. Chard also contains special phytonutrients that enhance nervous system and eye health.
4. Collards: In one study of eight green vegetables, collard greens showed the greatest capacity to bind to bile acids, so these are your greatest cholesterol-lowering allies. Steaming improves bile-acid binding. Add an apple to your collards and give your doctor the pink slip!
5. Spinach: Spinach is an incredibly versatile, mild green that’s easy to find and integrate. Use it in salads, hide it in smoothies, or tuck it into a lasagna or pasta sauce. It is rich in vitamin K, folate and magnesium, as well as anti-inflammatory flavonoids and carotenoids, making it excellent for the entire body. Raw spinach offers the most nutrition.
6. Broccoli and Broccoli Sprouts: Broccoli and their sprouts can challenge kale head-to-head for most nutritional potency. Broccoli is rich in lutein, sulforaphane, folate and carotenoids, and provides a trifecta of detox, anti-cancer and anti-inflammatory effects. Just half a cup a day can help, with three cups daily offering an optimal antioxidant load for protection. Broccoli sprouts are notable because they offer increased sulforaphane potency. The sprouts may also have antiviral capacity, specifically against influenza. “At even just 1/4 cup per day I’ve seen drastic changes in my clients’ health,” says Tom Malterre of Whole Life Nutrition. Add broccoli sprouts to salads, sandwiches, wraps, tacos, rice bowls or smoothies. Learn how to grow your own supply of sprouts by visiting The Magic of Microgreens.
7. Brussels Sprouts: Glucosinolates are the chemical starting points for a variety of cancer-protective substances. Brussels sprouts top even kale and broccoli in these special compounds, making them cancer-fighting heroes. The sulforaphanes present also support liver detoxification. Brussels sprouts are delicious prepared simply: Toss in olive oil, lemon juice, garlic, salt and pepper and roast, turning occasionally, in a 400-degree Fahrenheit oven until slightly charred.
8. Bok Choy: Like dandelion, bok choy is rich in calcium, as well as polyphenols and carotenoids. These nutrients reduce oxidative stress and protect against cancer, all while preserving bone density. Shred bok choy heads for a crunchy addition to salads; stir-fry them in an Asian-style sauté; or cut in half, coat with oil and a bit of white wine vinegar, and grill.
Try my favorite tips for eating three cups of green vegetables per day.
Toss baby spinach, baby kale or collard greens into your morning smoothie. This is a great way to sneak greens into breakfast or get them into the bodies of hesitant children.
Pre-make salads using heartier leafy greens. Try mixing romaine and kale so you have grab-and-go greens during the work week. Package greens in Mason jars and round out your salad with diced vegetables (buying precut fixings from your grocer’s salad bar saves prep time) and a hearty protein, such as marinated tempeh, diced chicken or leftover steak slices. Romaine will usually last for two days, and kale can keep three to four days depending on how fresh it is from the market.
Don’t forget frozen! Kale, collards and spinach can be found in the frozen foods section. Keep these greens on hand and throw a few handfuls into soups, stir-fries and even pasta sauce. Frozen greens are flash-frozen within 24 hours of picking and can be more nutrient-dense than what’s in the local market, especially during winter months.
The combination of warm spices and sweet apple makes these sautéed greens hearty and comforting.
• 1 tablespoon avocado oil (or other oil suited for high heat)
• 1 apple, peeled, cored and chopped into bite-sized pieces
• 1 small sweet onion, thinly sliced
• 1 bunch collard greens
• 1/2 teaspoon salt
• 1 teaspoon ground black pepper
• 1/2 teaspoon five-spice powder
• Juice of 1/2 lemon
• 1/2 cup bone broth or vegetable stock
1. Heat oil in stock pot until it thins and flows easily, indicating it’s hot. Add apples and onions, then sauté over medium-high heat for 5 to 7 minutes or until onions are slightly translucent and apples are partly browned.
2. While apples and onions are cooking, break down collards. One at a time, fold leaves in half so the stem is along one side and then rip the stem from the leaf. Stack de-stemmed leaves and roll them into a tight cigar. Using a sharp knife, slice across cigar, making ribbons.
3. Toss sliced greens into stockpot with apples and onions. Add salt, pepper and five-spice powder then sauté 5 to 10 minutes or until greens are wilted.
4. Squeeze lemon juice into stockpot and stir well to combine.
5. Add bone broth or vegetable stock and cover. Reduce heat to low and simmer for 20 to 30 minutes or until tender.
• 1 slice thickly cut bacon
• 1 pound Brussels sprouts
• 1/2 cup fresh or frozen cranberries or
• 3 tablespoon dried cranberries
• 1 tablespoon bacon fat (drained from bacon)
• 2-1/2 tablespoons pure maple syrup
• Kosher salt and freshly ground black pepper, to taste
• 1/4 cup pecans, chopped (optional)
1. Cook bacon in a hot skillet, then drain and reserve the fat. Preheat oven to 425 degrees Fahrenheit.
2. Cut Brussels sprouts in half.
3. In a large bowl, toss cranberries (if using fresh or frozen) and Brussels sprouts in maple syrup and reserved bacon fat. Sprinkle with salt and freshly ground black pepper.
4. Transfer sprouts mix to a roasting pan and place in hot oven. Roast for 15 to 20 minutes, until the edges are browned.
5. While sprouts are roasting, chop bacon into small pieces. Remove sprouts from oven and add bacon, pecans (if using) and dried cranberries (if using instead of fresh). Toss and serve.
Try serving this easy kale sauté as a nutrient-dense side to pasta dishes.
• 1/2 tablespoon coconut or avocado oil
• 1 small onion, sliced into thin rings, then quartered
• 1 heirloom tomato, chopped, or oil-packed sun-dried tomatoes, diced
• 1 large clove garlic, diced
• 12 ounces baby kale, or 1 bunch ‘Lacinato’ kale, destemmed
• 1/2 teaspoon salt
• Black pepper, to taste
• 1 teaspoon Italian seasoning
1. Heat oil in stock pot. Add onion and tomato, cooking until onion softens, 5 to 10 minutes.
2. Add garlic, kale, salt and pepper. Stir often until kale wilts and reduces significantly in size. Add Italian seasoning and mix well. Serve warm.
All recipes from the kitchen of Vibrance Nutrition.
Aimee Gallo is a functional nutrition coach and founder of Vibrance Nutrition. A lifelong advocate of preventing disease through proper nutrition, she loves to sauté, blend, bake and ferment all sorts of greens and strongly advocates for their regular appearance on the dinner plate. Aimee is especially looking forward to coaching and inspiring others this spring during her free online Glorious Greens challenge. Learn more at Facebook/VibranceNutrition.
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