Question: What's the most nutritious lettuce?
Answer: All types of lettuce are good for you. As a vegetable, lettuce provides fibre, vitamins, minerals and phytochemicals for very, very few calories. With respect to vitamins, lettuce is a source of folate, a B vitamin needed to make and repair DNA in cells, and vitamin K, a nutrient linked to healthy bones. You also get potassium, a mineral important for healthy blood pressure, as well as a little calcium in lettuce.
Lettuce is also a good source of two phytochemicals: beta-carotene and lutein. Beta-carotene is a powerful antioxidant, protecting cells in the body from damage caused by free radicals. In fact, its antioxidant properties are thought to help prevent certain cancers and other diseases.
Lutein is also an antioxidant that helps preserve our eyesight as we age. Once consumed, lutein makes its way to the eye where it protects the retina and lens from free radical damage. Research shows that people who have high intakes of lutein from foods are less likely to develop cataract and macular degeneration. (Macular degeneration attacks the central part of the retina called the macula, which controls fine, detailed vision. The condition results in progressive loss of visual sharpness and is the leading cause of severe vision loss in older adults. )
That said, you can't count on all types of lettuce to be a good source of all vitamins, minerals and antioxidants. In general, lettuce that is darker green in colour is a better source of nutrients than lighter coloured lettuce. So, to answer your question, the most nutritious lettuce is Romaine. Compared to red leaf, green leaf, butterhead (Boston and bib types) and iceberg, it delivers more folate, potassium, beta carotene and lutein.
Per one cup serving (shredded), Romaine has 2.5 milligrams of beta-carotene, 1.1 milligrams of lutein and one-third of a day's worth of folate. Compare that to iceberg, the least nutritious type of lettuce: one cup (shredded) contains 0.2 milligrams of beta-carotene, 0.2 milligrams of lutein and only one-third of the folate found in Romaine.
When it comes to getting the most vitamins, minerals and antioxidants per serving, here's my rating of types of lettuce from most to least nutritious: Romaine, green leaf, butterhead (Boston, bib), red leaf, and finally, iceberg.
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