Lettuce, cos or romaine, raw
Whole food · Vegetables and Vegetable Products
Photo: Wikipedia
Cos or romaine lettuce is a tall, crisp lettuce with a sturdy, pale-green rib and tender, dark-green leaves that offer a satisfying crunch. Its flavor is mildly sweet and refreshing, with a subtle, almost nutty undertone that distinguishes it from other lettuces. Despite being very low in calories, it's a surprisingly good source of vitamins A and K, providing over 60% of the daily value for vitamin K in a single cup.
💚 Why it's loved
People love romaine for its signature crunch and sturdy texture that holds up beautifully in salads and sandwiches without wilting. Its mild, sweet flavor makes it a versatile canvas for bold dressings, from classic Caesar to tangy vinaigrettes.
⚠️ Watch-outs & how to enjoy it better
Romaine lettuce, like other leafy greens, contains natural compounds called oxalates which can contribute to kidney stone formation in susceptible individuals. To mitigate this, ensure adequate hydration and consider pairing it with calcium-rich foods like cheese or yogurt, which can bind oxalates in the digestive tract. The sturdy ribs can also be tough for some, so using only the tender leaves or massaging them with dressing can improve palatability.
Key benefits
- Excellent source of vitamin K, essential for bone health and blood clotting.
- Very low in calories and carbohydrates, making it ideal for weight management.
- Provides a good amount of vitamin A, supporting vision and immune function.
- High water content helps with hydration.
- Contains folate, important for cell function and tissue growth.
🍽️ Popular dishes
🌍 Where it's eaten
💡 Did you know?
The name 'romaine' is believed to come from the Romans, who brought this lettuce to the rest of Europe from Egypt, where it had been cultivated for millennia.
Full nutrition (scales with serving)
| Water | 94.7 g |
| Energy (Atwater General Factors) | 20.0 kcal |
| Energy (Atwater Specific Factors) | 17.0 kcal |
| Energy | 17.0 kcal |
| Energy | 70.0 kj |
| Nitrogen | 0.20 g |
| Protein | 1.2 g |
| Total lipid (fat) | 0.26 g |
| Ash | 0.55 g |
| Carbohydrate, by difference | 3.2 g |
| Carbohydrate, by summation | 3.0 g |
| Fiber, total dietary | 1.8 g |
| Fiber, soluble | 0.10 g |
| Fiber, insoluble | 1.7 g |
| Sugars, Total | 1.2 g |
| Sucrose | 0.00 g |
| Glucose | 0.39 g |
| Fructose | 0.80 g |
| Lactose | 0.00 g |
| Maltose | 0.00 g |
| Galactose | 0.00 g |
| Starch | 0.00 g |
| Calcium, Ca | 35.0 mg |
| Iron, Fe | 0.95 mg |
| Magnesium, Mg | 13.7 mg |
| Phosphorus, P | 30.0 mg |
| Potassium, K | 253 mg |
| Zinc, Zn | 0.25 mg |
| Copper, Cu | 0.05 mg |
| Manganese, Mn | 0.13 mg |
| Selenium, Se | 0.40 ug |
| Vitamin C, total ascorbic acid | 4.6 mg |
| Thiamin | 0.08 mg |
| Riboflavin | 0.07 mg |
| Niacin | 0.32 mg |
| Pantothenic acid | 0.14 mg |
| Vitamin B-6 | 0.08 mg |
| Folate, total | 50.0 ug |
| Vitamin A, RAE | 436 ug |
| Carotene, beta | 5230 ug |
| Carotene, alpha | 0.00 ug |
| Cryptoxanthin, beta | 0.00 ug |
| Lycopene | 0.00 ug |
| Lutein + zeaxanthin | 2310 ug |
| Phytoene | 0.00 ug |
| Phytofluene | 0.00 ug |
| Vitamin E (alpha-tocopherol) | 0.14 mg |
| Tocopherol, beta | 0.00 mg |
| Tocopherol, gamma | 0.32 mg |
| Tocopherol, delta | 0.01 mg |
| Tocotrienol, alpha | 0.03 mg |
| Tocotrienol, beta | 0.00 mg |
| Tocotrienol, gamma | 0.00 mg |
| Tocotrienol, delta | 0.00 mg |
| Vitamin K (phylloquinone) | 102 ug |
| Vitamin K (Dihydrophylloquinone) | 0.00 ug |
| 5-methyl tetrahydrofolate (5-MTHF) | 40.0 ug |
| Tryptophan | 0.01 g |
| Threonine | 0.04 g |
| Isoleucine | 0.04 g |
| Leucine | 0.08 g |
| Lysine | 0.06 g |
| Methionine | 0.01 g |
| Cystine | 0.01 g |
| Phenylalanine | 0.07 g |
| Tyrosine | 0.02 g |
| Valine | 0.06 g |
| Arginine | 0.05 g |
| Histidine | 0.02 g |
| Alanine | 0.06 g |
| Aspartic acid | 0.14 g |
| Glutamic acid | 0.18 g |
| Glycine | 0.05 g |
| Proline | 0.04 g |
| Serine | 0.05 g |
| 10-Formyl folic acid (10HCOFA) | 9.0 ug |
| 5-Formyltetrahydrofolic acid (5-HCOH4 | 5.0 ug |
FAQ
Is romaine lettuce safe to eat raw?
Yes, it is commonly eaten raw. However, as with any fresh produce, it should be thoroughly washed under running water to remove dirt and potential contaminants.
What's the difference between romaine and iceberg lettuce?
Romaine has a more elongated shape, darker green leaves, and a more pronounced, sweet flavor with a sturdy crunch. Iceberg is rounder, paler, milder, and has a higher water content, making it less nutrient-dense.
How do I store romaine lettuce to keep it fresh?
Wrap the unwashed head in a dry paper towel, place it in a plastic bag, and store it in the crisper drawer of your refrigerator. This can help it stay fresh for up to a week.