Go Green With Kale
This week, kale is topping our ingredients list, so let’s dig in to the benefits of leafy green vegetables! It is no surprise that salads are healthy, but you may or may not know about some of the deeper, darker varieties of greens that are considered super vegetables. What does the science show, and what on earth is a “superfood”?
Sometimes, it’s as easy as looking at your food. Researchers have investigated the relationship between the color of fruits and vegetables and their total amount of antioxidants and found a rough correlation, but it’s not perfect. For a real-world example, picture kale and celery. Which one is more colorful? To get as much vitamin C as you have in one cup of raw kale, you would have to eat 37 stalks of celery. And then there’s trusty iceberg lettuce, the staple of the 1950s pre-dinner salad. Looking for vitamin A? You’d have to eat 20 times the amount of iceberg vs kale….and wouldn’t have much room left for dinner. Not a surprise, just based what we know about deeply-colored foods.
If you want to get more technical, when gauging the potential benefits of foods, scientists explore many aspects of nutritional content including vitamins, minerals, phytochemicals, antioxidants, fiber and other key components. (Check out the definitions below.) Superfoods are whole ingredients (often plant-based) that are nutritionally dense with these substances. For the average person, this can be a lot of info to measure and keep track of.
Fortunately, the Centers for Disease Control and Prevention (CDC) published a guideline on what it calls “Powerhouse Fruits and Vegetables,” which it defines as “foods most strongly associated with reduced chronic disease risk.” Researchers ranked 47 common fruits and veggies in order of nutrient density to help better define which foods are the best to support your long-term health. Topping this list are more than 16 leafy green vegetables including:
– Spinach: Popeye was right! Rich in vitamins A, C, and K, magnesium, iron and manganese, this mighty leaf is delicious raw or cooked (especially with lots of garlic).
– Romaine Lettuce: This humble standard salad green boasts a healthy offering of fiber, folate, vitamins A, C, and K and a tasty crunch too!; and our star of this week,
– Kale: This versatile green is full of fiber, antioxidants, calcium, vitamins C and K, iron, and other key nutrients. Kale is also a cruciferous vegetable, so it’s especially high in glucosinolates, which are converted by your body to antioxidant and anti-inflammatory compounds. Read more about broccoli (another member of the cruciferous family) and prostate cancer here.
Find more brightly-colored vegetables in our guide to eating, exercise, and rest: The Science of Living Well, Beyond Cancer.
Kale: Raw and Cooked
Raw: Kale can be a delicious base for a crunchy salad or slaw. But it can be flavorless and tough without a little TLC first. To make your raw kale dish extra delicious, we recommend massaging it to help break down the cellulose in plant cell walls and improve texture.
To prep, remove the tough center stems (discard them, or you can use them for soup stock or compost) and roughly chop the kale. To get the best texture, sprinkle the leaves with a pinch of salt and a squeeze of lemon juice or a splash of your favorite vinegar. The acid will also help break down the cellulose. Rub the leaves together between your fingers and squeeze them until they just start to soften (don’t overdo it – mushy kale isn’t great either). You can also rinse after massaging remove the bitter compounds that form when you break apart the plant cells. Now, your salad base is ready.
Consider adding your favorite sliced fruit and chopped nuts for a tasty salad. Finish with a sprinkle of olive oil, more lemon juice or vinegar, and salt & pepper. This week’s grocery list features apples and almonds, so you could knock off 3 foods in a single meal. But don’t stop there…..
Cooked: Kale is also delicious when cooked. One option is to chop it very thinly against the grain (i.e., across the stem) and sauté in a little bit of olive oil, garlic, salt, and pepper for a quick and healthy dish. Keep the stems – they’ll add a bit of a crunchy flavor pop when cooked. You could also add a handful of chopped kale to finish your favorite soup or stew.
Glossary of terms:
Antioxidants: substances that can prevent or slow damage to our body’s cells.
Fiber: also known as “roughage,” this includes the parts of foods your body can’t completely digest or absorb. Providing bulk in the gut, they can help with digestion generally, and even lower blood cholesterol and glucose levels. Fiber is food for your microbiome, the “good” bacteria that produce beneficial compounds for you if you feed them well!
Minerals: naturally-occurring substances that help our bodies develop and function normally. Those most essential for health include calcium, phosphorus, potassium, sodium, chloride, magnesium, iron, zinc, iodine, chromium, copper, fluoride, molybdenum, manganese, and selenium.
Phytochemicals: these are naturally occurring chemicals in plants; antioxidants are one example. Science is only just beginning to understand their potential, but these compounds may go a long way toward keeping us healthy and possibly even preventing and fighting disease.
Superfoods: a non-scientific term for unprocessed foods full of healthy compounds
Vitamins: substances that are needed for normal cell function, growth, and development. Some vitamins function as antioxidants. Fruits and vegetables are an excellent source for these compounds.