I've read that lettuce actually has very little nutritional value, but I also hear that people need to eat more leafy greens. Isn't lettuce a "leafy green"? What's the real story?
It depends what you mean by "lettuce." If you're talking about iceberg or some other variety of tightly-wrapped, pale green head lettuce (or, more accurately, "crisphead" lettuce), then you're right, it does have very little nutritional value -- only about 7 percent of the vitamin A you need in a day, for example, and 3 percent of vitamin C. At the same time, it's 95 percent water, which means it helps keep you hydrated, and, some scientists say, will help you feel full. And, it has very few calories -- only 10 in a full cup of shredded lettuce.
So iceberg lettuce should hardly be classified as junk food. It's just not the most nutrient-dense choice you could make for your salad.
In contrast, one cup of shredded romaine lettuce gives you 55 percent of your daily intake of vitamin A, and 20 percent of vitamin C. Green leaf lettuce is almost as good, offering almost as much vitamin A and about 10 percent of vitamin C. Even butterhead lettuce (boston or bibb type) offers 35 percent of vitamin A, though not much vitamin C.
Vegetables that are better for you tend to be richer in color. The deep green leaves of "iceberg alternatives" tend to offer more folate, potassium and magnesium, as well as antioxidants of beta-carotene, lutein and zeaxanthin. And the darker the leaf, the more phytonutrients (a fancy name for "plant nutrients") you can expect to get.
If you're the adventurous type, you may consider trying other types of leafy greens in your salad -- spinach, collard greens, swiss chard and bok choy are among the more mild-flavored. Greens with a stronger flavor include mustard greens, arugula, mizuna and turnip greens. Kale falls somewhere in-between.
The MyPyramid Food Guidance System recommends anywhere from 1.5 to 3 cups of dark green vegetables -- a category that also includes broccoli -- each week. There's a trick, though: Leafy greens count for only half -- you need two cups of lettuce or leafy greens to count as one cup of dark green vegetables. Keep that in mind when you're at the salad bar.
Chow Line is a service of Ohio State University Extension and the Ohio Agricultural Research and Development Center. Send questions to Chow Line, c/o Martha Filipic, 2021 Coffey Road, Columbus, OH, 43210-1044, or filipic.3@cfaes.osu.edu.
This column was reviewed by Jaime Foster, registered dietitian and program specialist for Ohio State University Extension in the Department of Human Nutrition, College of Education and Human Ecology.
To receive a PDF file of Chow Line via e-mail, contact Martha Filipic at filipic.3@cfaes.osu.edu.