Bok choy and kale are among the nutrient-rich greens you can add to a salad. Photograph: Anastasiya Mihailovna/Getty Images View image in fullscreen Bok choy and kale are among the nutrient-rich greens you can add to a salad. Photograph: Anastasiya Mihailovna/Getty Images Well actually Iceberg, romaine, kale: which salad greens are healthiest? If you’re trying to meet your daily serving of 2.5 cups of vegetables, you might have some questions
Prefer the Guardian on Google I f you want to eat lettuce, that no longer just means iceberg. In our bountiful age, there are many options: romaine, red-leaf lettuce, butter lettuce, beet greens, bok choy, bitter radicchio, every developmental stage of arugula.
Sometimes, it’s simply up to preference. But if you’re trying to meet your daily serving of 2.5 cups of vegetables – or you’re rethinking your salad choices amid the US cyclospora outbreak , you might have some questions about which greens to go with.
Health authorities widely agree that a diet high in nutrient-dense fruits and vegetables is associated with reduced chronic disease risk. But which greens are giving you the most nutritional bang for your buck?
“Nutrient density”, defined as the “nutrients per calorie” of a food, can be a factor when shopping for produce, notes Jamie Mok , a Los Angeles–based registered dietitian nutritionist.
In 2014, the Centers for Disease Control and Prevention released a study attempting to help people better understand nutrient density via a ranking system that declared watercress a powerhouse champion, with 17 nutrients per calorie – almost twice the nutrient density as kale .
View image in fullscreen The CDC recently declared watercress a nutrient powerhouse. Photograph: haoliang/Getty Images “Watercress is rich in vitamin K, vitamin C, minerals like calcium, manganese, copper and lots of phytochemicals, which are beneficial compounds that we find in plants,” says Mok, who grew up eating watercress in Chinese soups her mother made. “It’s a very light, delicate flavor.”
This doesn’t mean you should opt for watercress and ban other greens from your crisper. While watercress grabbed the CDC’s top spot, many other cruciferous greens, like green or Napa cabbage, kale or arugula, boast similar, substantial health benefits.
“Cruciferous vegetables contain a group of compounds called glucosinolates,” as well as vitamin C, vitamin K and fiber, explains Mok. “These are sulfur-containing compounds that have antioxidant activity.” Researchers believe glucosinolates support cancer-prevention .
Rather than focusing on only the most nutrient-dense greens, experts advise prioritizing variety. Even the fruits and veggies that scored lower on the CDC’s ranking, such as blackberries, leeks and sweet potatoes, offer their own substantial health benefits – they simply don’t have the breadth of nutrients cruciferous veggies pack per calorie.
Read more “I don’t encourage people to focus on finding one ‘best’ leafy green,” says Dr Nina Cherie Franklin, a research scientist and health coach who goes by “ That Salad Lady ”. “Eating a variety is almost always the better approach. Spinach, kale, watercress, romaine, arugula, chard, collards, mustard greens, turnip greens and dandelion greens all bring something different to the bowl.”
For instance, one cup of shredded cabbage will net you about 2g of fiber and 28mg of vitamin C, but no vitamin A. A cup of spinach contains 1g of fiber, 9mg of vitamin C and 16mcg of vitam…