If there's one food that no one -- not your doctor, your nutritionist or even your mother -- will tell you to eat less of, it's leafy greens. Calorie for calorie, chard, collards, kale and other leafy greens may just be the most nutritious food you can eat. They're packed with vitamins -- A, B, K and others -- but also rich in essential minerals like calcium, iron, potassium and magnesium, as well as antioxidants, which protect cells against damage. Leafy greens contain phytochemicals, natural compounds that can help prevent hardening of the arteries and lower inflammation linked to heart disease. The greens' synergistic combination of vitamins, minerals, antioxidants and phytochemicals helps detox cells and expunge free radicals that damage DNA, both of which may inhibit cancer cells from forming and multiplying.
Greens are also your single best source of natural nitrates, which get converted by the body into nitric oxide, a gas that lowers blood pressure, promotes blood flow and can even improve sexual function in men. You produce less nitric oxide as you age -- levels can dip by half after age 40 -- which means you need to eat even more nitrates to keep everything working properly, says University of Texas biochemist Nathan Bryan. As if that weren't enough, greens have been shown to boost mental clarity, prevent depression and reduce the risk of diseases like Alzheimer's. If you're looking to stay lean, high-fiber greens help speed digestion and make you feel full, and they're low in carbohydrates and calories, so you can practically eat as much of them as you want. At the very least, aim to consume three to five ounces of leafy greens a day, says Bryan. Here's how to get your fill.
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The 10 Healthiest Fruits and Vegetables
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6 Healthy Foods That Get a Bad Rap