from the dr. mirkin newsletter
Dear Dr. Mirkin: Is it true that iceberg lettuce is completely devoid
of nutrition?
It's not devoid of nutrition, just a less concentrated
source of nutrients that the darker green leaf lettuces, spinach
and other leafy greens. Lighter colors in vegetables mean they
contain more water and therefore fewer nutrients "per cubic
inch." Here's a comparison of one cup of iceberg lettuce to
romaine lettuce: The iceberg lettuce contains 11mg calcium,
11mg phosphorous, .3mg iron, 88mg potassium, 19RE vitamin A,
and 2mg vitamin C; while the romaine lettuce has 20mg calcium,
25mg phosphorous, .6mg iron, 162mg potassium, 146RE vitamin
A, and 13mg vitamin C. Both have 7 calories, 1g protein, 1g
carbohydrate, 1g fiber. So iceberg lettuce is a perfectly good
food, but darker lettuces are even better.