We have all heard it since we were small; eat your vegetables!
When I was growing up, on weeknights especially, those veggies often came from a can, perhaps a mix of green peas and carrots. Fast forward to today and now I linger in the produce aisle, looking for a new heirloom vegetable to try or making trade-offs between organic and conventional options. This gave me pause to ask myself – how did I get here and what have I learned along the way?
When I first became plant-based, choosing a vegetable to eat was all about the recipe. I looked through a cook book or online, made a list of specific ingredients and went to the store. And if one store didn’t have a specific vegetable, rather than try a substitute, I was known to drive to other stores till I found it. Back home, it was all about making a successful, delicious and healthy meal. All vegetables were equal.
But over time, I became a student of the evidence-based science of good nutrition and curious as to how certain foods help us heal. With each book, doctor, research study, and certification, I realized that, in addition to eating a rainbow for good health (which was always a good idea), dark leafy greens were special, and even deserving of their own food category.
Kale: The popular kid, who knew?
As a reminder of where plant-based eaters get our nutrients, such as protein, calcium, vitamins and minerals, I posted a list in my kitchen. This was so I would remember and have confidence when doubting visitors would ask. My husband was the first to notice that dark green leafy vegetables were packed with nutrients and under almost every category – fiber, folate, iron, calcium, zinc, magnesium, vitamins A, B, C and K, antioxidants and so on. For me, this was puzzling. As one who learned long ago that the color of our fruits and vegetables is a good indicator of the vitamins they contain, I assumed that dark greens contained mostly chlorophyll. Mind you, this was before people started wearing Kale t-shirts.
Last year, when discussing with an arborist how leaves change color in the fall, I realized the clue I had been missing. The chlorophyll in the leaves on the trees absorbs red and blue light from sunlight and therefore the light that reflects appears green to our eyes. When the leaves ‘change’ color, they are actually revealing the true colors within. So too, the dark green colors of leafy vegetables are really just masking all the nutrients within. The rainbow of colors (and nutrients) is in there, hidden under the chlorophyll.
As I learned about how important these nutritionally dense foods were to our health, they went from bitter outcast to popular side dish. I wanted to learn all about the health benefits of dark green leafy vegetables and how to prepare them in delicious ways so I would eat them more often.
Greens: It Does a Body Good
In addition to popular salad greens such as Romaine, Mesclun, Red Leaf Lettuce, Baby Greens, Spinach, and Broccoli Sprouts, dark green leafy vegetables are nutrition powerhouses: low in calories and fat, full of fiber and antioxidants. As a result, they help us to lose weight by displacing other high calorie foods and slow the aging process. They can be served steamed, cooked or massaged, which often helps take the edge of any that have a bitter flavor.
Examples of nutritionally dense greens include…
Asparagus, Arugula, Beets, Beet Greens, Broccoli Rabe, Bok Choy, Brussels Sprouts, Cabbage, Chicory, Cilantro, Collard Greens, Endive, Kale (Curly or Lacinato), Microgreens, Mustard Greens, Parsley, Spinach, Sweet Potato Leaves, Swiss Chard, Turnip Greens and Watercress.
So why are they deserving of their own category?
The USDA recommends that adults consume at least 3 cups of dark greens each week. But if you are trying to stop and even reverse heart disease, the research shows the value of eating more, much more.
Here are some of the many health benefits of dark green leafy vegetables:
Healthy Heart
For those with advanced heart disease looking to stop and even reverse it, Dr. Caldwell Esselstyn, surgeon and author of Prevent and Reverse Heart Disease (2007), suggests that, in addition to a healthy whole food plant-based diet low in fat, we specifically include a fist full of cooked dark greens ideally served with some balsamic vinegar (no oil) 6 times a day at least for a few months and monitor results. For the rest of us, the more dark greens the better as a healing measure, both when facing a health crisis or to prevent one. You can hear Dr. Esselstyn’s description (video, starting at 38:27 mark for about 5 minutes to 43:51) of why eating and specifically chewing our greens matters and how the resulting nitric oxide protects our endothelial cells from oxidative inflammation and heart attacks.
Ensuring good sources of whole food nitrates, especially Kale, Arugula, Swiss Chard, Spinach, Beet Greens and Beets, and chewing our food allows nitric oxide to form. This is especially important for those over 50 who’s body typically makes only half of the nitric oxide our bodies made when we were 25. On top of a plant-based diet, the more greens we eat, the more we can protect ourselves from a sudden heart attack.
Many who have heart disease are also on blood thinners and are cautioned about eating dark greens that are high in Vitamin K and can reduce the effectiveness of their medication. For example, Swiss chard has 3x the RDA in a single cup. However, the issue is really one of consistency.
According to Dr. Esselstyn’s FAQ page, “Coumadin (Warfarin) is an anti-clotting drug shown to have significant benefit in protecting people with atrial fibrillation from having a stroke. Can patients on Coumadin eat all the green leafy vegetables with vitamin K, which may shorten their clotting time? The answer most emphatically is YES! Inform the physician who is monitoring the Coumadin and clotting time that you are regularly going to be eating copious amounts of healthy green leafy vegetables. He/she will appropriately adjust the Coumadin dose”.
For those on blood thinners, it is important to be consistent and commit to eating the same amount of greens every day. There are many other benefits. For example, steamed Kale, Collard and Mustard Greens contain compounds that have been shown to excrete bile acids, including cholesterol, out of the body and may lower LDL levels and risk of heart disease. Consuming higher amounts of Vitamin C (134% RDA in 1 cup of kale) and potassium (high levels in spinach) have also been linked to healthier blood pressure levels.
Strong Bones
Thanks to the dairy industry’s sizable marketing budget, we have all been taught that dairy is an excellent source of calcium needed to strengthen our bones. But nutrition comes down to not what you consume but what your body does with your food and what you absorb. Dairy actually does your body no good and causes your bones to release and actually deplete your calcium stores. Dark greens are a great source of plant-based calcium and Vitamin K for bone health. A cup of cooked collard greens provides 27% of the RDA for calcium for an adult. Arugula, collards and turnip greens are good sources of readily available calcium but spinach and swiss chard only make a small percentage of calcium and iron available for absorption. The body knows when it has found a good source of calcium because of the bitter taste of calcium rich plant-foods.
Lose Weight
Dark greens are high in nutrients and low in calories. By including dark greens with every meal, even breakfast, you are getting fiber and protein and displacing other high calorie foods and otherwise bad choices. High fiber foods are more filling and, with a whole food and low fat plant-based diet, it becomes easy to lose weight without counting calories, points or carbs.
Protection for Eyes
Spinach and other dark leafy greens contain the carotenoids lutein and zeaxanthin, which are stored in the retina and act like a natural sunblock to filter out damaging light and protect our eyes from free radical damage. Kale is very high in beta-carotene which the body turns into Vitamin A. A single cup of kale contains over 200% of the RDA from Vitamin A (from beta- carotene). Eating foods rich in these antioxidants retards cataracts, improves vision and maintains eyesight for the long term.
Lessen Disease Risk
Nutrient deficiency is often associated with disease risk. For example, a magnesium deficiency has been shown to contribute to insulin resistance and Type 2 Diabetes. A big spinach salad can provide 20% of one’s daily magnesium requirement. An increase of 1 serving/day of green leafy vegetables has been shown to lower Diabetes risk by as much as 9%. Antioxidants and phytonutrients have been shown to be protective from oxidation and the free-radical damage typically associated with aging and cancer. Who doesn’t want to slow the aging process?
Keep Brain Young
Nutritional epidemiologists at Chicago’s Rush University Medical Center led by Martha Clare Morris, PhD, estimate that those eating about 1.3 servings of leafy green vegetables per day had brains that were as much as 11 years younger after controlling for other lifestyle variables such as smoking, physical activity etc. And a recent study in Neurology found that those consuming a similar serving size of green vegetables had fewer memory problems and less cognitive decline. More research needs to be done on cognitive decline but this is a great reason to add more dark leafy greens to your lifestyle. You have nothing to lose but possibly your chances of memory loss.
I realize now the amazing healing power of eating dark leafy green vegetables so, in addition to eating a rainbow, I try to eat dark leafy greens as an important part of almost every meal, just for the health of it.
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