Protein
Believe it or not, romaine lettuce is a complete protein! That means that it has all 8 essential amino acids, According to Joel Fuhrman, M.D., a head of romaine lettuce is approximately 50% protein by calorie, which is more protein per calorie than chicken.
Reduces Cholesterol
Since romaine is high in fiber it helps reduce cholesterol. In the colon, fiber binds to bile salts and removes them from the body. This forces the body to make more bile, which is helpful because it must break down cholesterol to do so. This is just one way in which fiber is able to lower high cholesterol levels.
Helps lower blood pressure
In addition, romaine lettuce is a very good source of potassium, which has been shown in numerous studies to be useful in lowering high blood pressure, another risk factor for heart disease
Rich in B-vitamins: especially Folate (B9)
Romaine has 213% RDA of folate in a 2 cup serving. This B vitamin is needed by the body to convert a damaging chemical called homocysteine into other, benign substances. If not converted, homocysteine can directly damage blood vessels, thus greatly increasing the risk of heart attack and stroke. A small head of romaine also contains Thiamine (B1) - 38% RDA, Riboflavin (B2) - 32% RDA, Niacin (B3) - 12% RDA, Pantothenic Acid (B5) - 18%, Pyridoxine (B6) - 36 %,
Good for Your Heart
Romaine's vitamin C and beta-carotene content make it a heart-healthy green. Vitamin C and beta-carotene work together to prevent the oxidation of cholesterol. When cholesterol becomes oxidized, it becomes sticky and starts to build up in the artery walls forming plaques. If these plaques become too large, they can block off blood flow or break, causing a clot that triggers a heart attack or stroke.
Rich Source of vitamin A.
According to the CDC, a 2 cup serving of romaine lettuce provides 140 percent of the daily recommended vitamin A requirement. Vitamin A is good for your eyes, good for keeping your skin healthy and for fighting off infection & disease.
High in Vitamin K
Two cups of Romaine provide 120% of your daily requirement for vitamin K. Vitamin K is an essential nutrient necessary for blood clotting - it regulates normal blood clotting by helping the body transport calcium. Vitamin K may also be helpful for bone health: it may reduce bone loss, and decrease risk of bone fractures. It also may prevent calcification of arteries and other soft tissue.
Mineral-Rich
Don't let the lighter color of romaine lettuce fool you. This not-so-dark leafy green is rich in minerals including calcium, magnesium, potassium and iron.
Water
One small head of romaine provides 16% of your daily water needs with about 20 ounces of water per head!