Romaine lettuce, also known as cos lettuce, is the most nutritious of all lettuces and is an excellent source of Vitamin C - more than five times that of iceberg lettuce.
This salad vegetable has deep green, long leaves with a crisp texture and a stronger flavor than iceberg lettuce, and is more tender and sweeter than other lettuce varieties. Like all lettuces, it has a low-calorie content and high water volume.
In addition to its high Vitamin C content, romaine lettuce is also an excellent source of Vitamin A. Research has shown that to absorb maximum Vitamin A from this salad leaf, it should be combined with a fat, such as olive oil from salad dressing.
Romaine lettuce is also a rich source of folic acid, and contains phosphorus, potassium and fiber. Phytochemically, this form of lettuce is a good source of lutein and zeaxanthin - these phytochemicals are important antioxidants that battle many diseases. Romaine lettuce also contains a significant amount of lactucaxanthin, which is a rare dietary carotenoid that was found to suppress the Epstein-Barr virus, one of the most common viruses in humans.
Romaine lettuce is rich in lutein and zeaxanthin, which are carotenoids found naturally in the eye that fight age-related macular degeneration, the leading cause of irreversible vision loss in the elderly.
In a study conducted in the US, it was found that starting off a meal with a low-calorie salad gave a sense of fullness and reduce subsequent calorie intake, which may be an effective way for managing weight.
Salicylic acid, a main compound found in aspirin, which is used to treat inflammation, has been found in romaine lettuce. Salicylic acid is a cyclooxygenase-2 (COX-2) inhibitor, a key enzyme involved in inflammation, certain cancers, and the promotion of heart disease.
Tips for Using Lettuce
- Look for lettuce with large, darker-green, unwilted outer leaves, as the darker the leaves, the more nutrients they contain.
- Store lettuce and other salad vegetables in the refrigerator, where they should keep for up to ten days.
- Brown MJ et al. Carotenoid bioavailability is higher from salads ingested with full-fat than with fatreduced salad dressings as measured with electrochemical detection. Am J Clin Nutr. 2004 Aug;80(2):396-403.
- Batra KK, Wagner JR, Stokstad EL. Folic acid compounds in romaine lettuce. Can J Biochem. 1977 Aug;55(8):865-8.
- Mozaffarieh M, Sacu S, Wedrich A. The role of carotenoids, lutein and zeaxanthin, in protecting against age-related macular degeneration: A review based on controversial evidence. Nut J. 2003;2:20-28.
- Rolls Bj, Roe LS, Meengs JS. Salad and satiety: energy density and portion size of a first-course salad affect energy intake at lunch. J Am diet Assoc. 2004; 104: 1570-1576.
- Ingster LM, Feinleib M. Could salicylates in food have contributed to the decline in cardiovascular disease mortality? A new hypothesis. Am J Public health.. 1997;87:1554-1557.
- Paterson JR, Lawrence JR. Salicylic acid: a link between aspirin, diet and the prevention of colorectal cancer. QJM. 2001;94:445-448.