Whole food · Vegetables and Vegetable Products
Photo: Wikipedia
Romaine lettuce is a crisp, elongated leaf with a sturdy, pale rib and a fresh, mildly sweet, slightly bitter flavor. Its satisfying crunch and refreshing juiciness make it a staple in salads and sandwiches. Nutritionally, it's exceptionally low-calorie (21 kcal/100g) and provides a good source of vitamin A (as beta-carotene) and vitamin K.
People love romaine for its perfect balance of crisp texture and mild, sweet flavor that acts as a versatile canvas for other ingredients. It's the iconic backbone of the Caesar salad, beloved for its ability to hold up to creamy dressings without wilting.
Romaine lettuce can be a vehicle for foodborne illnesses like E. coli if contaminated, as it's often consumed raw. Those on blood thinners should be mindful of its vitamin K content, which can interfere with medication. To counteract risks, always wash leaves thoroughly under running water, even pre-washed bags, and consult a doctor about consistent intake if on anticoagulants.
Ancient Egyptians cultivated romaine lettuce not for its leaves, but for its seeds and oil-rich stem, which they used to produce a form of lettuce oil.
| Water | 94.3 g |
| Energy (Atwater General Factors) | 20.8 kcal |
| Energy (Atwater Specific Factors) | 17.5 kcal |
| Nitrogen | 0.16 g |
| Protein | 0.98 g |
| Total lipid (fat) | 0.07 g |
| Ash | 0.61 g |
| Carbohydrate, by difference | 4.1 g |
| Calcium, Ca | 27.6 mg |
| Iron, Fe | 0.27 mg |
| Magnesium, Mg | 12.1 mg |
| Phosphorus, P | 23.4 mg |
| Potassium, K | 260 mg |
| Sodium, Na | 23.0 mg |
| Zinc, Zn | 0.25 mg |
| Copper, Cu | 0.05 mg |
| Manganese, Mn | 0.23 mg |
| Thiamin | 0.06 mg |
| Niacin | 0.37 mg |
| Vitamin B-6 | 0.06 mg |
| Vitamin K (phylloquinone) | 83.4 ug |
| Vitamin K (Dihydrophylloquinone) | 0.00 ug |
| Vitamin K (Menaquinone-4) | 0.00 ug |
Is the dark green leaf part of romaine more nutritious than the pale rib?
Yes. The darker outer leaves contain significantly more beta-carotene (vitamin A) and chlorophyll than the paler, watery inner ribs, though both parts are nutritious.
How do I keep romaine lettuce fresh longer?
Wrap the unwashed head in a dry paper towel and place it in a perforated plastic bag in the crisper drawer. This absorbs excess moisture, which causes slime and decay.
Can I cook romaine lettuce?
Absolutely. Romaine's sturdy structure holds up well to quick grilling or sautéing, which brings out a sweeter, smokier flavor and a tender-crisp texture, perfect as a side dish.