What the evidence says. Several controlled trials; effects real but modest or context-dependent.
Nutrition per serving 1 cup shredded, raw (47 g)
Sugars0.6 g1%
Fibre1 g2%
Protein0.6 g1%
Other44.8 g95%
What's in one serving, by weight — average composition (USDA).One serving as % of the adult daily requirement (FDA Daily Values). The bold outer ring = 100% of a day's needs.
Romaine Lettuce is a vegetable used for supports blood-pressure regulation via dietary nitrate. NutriDex grades the human evidence as Moderate. Romaine is a nutrient-dense, water-rich leafy green: a single shredded cup is roughly 8 kcal yet supplies meaningful vitamin K, provitamin-A carotenoids, and folate. As one of the higher-nitrate leafy greens, it shares the bioactive profile (dietary nitrate, lutein/zeaxanthin, vitamin K, folate) tied in human studies to lower cardiovascular risk, slower cognitive decline, and reduced progression of age-related macular degeneration. The strongest randomized evidence is indirect, coming from inorganic-nitrate and lutein/zeaxanthin trials rather than romaine itself; whole-diet leafy-green data are observational but consistent.
Purported Benefits
✓Supports blood-pressure regulation via dietary nitrate
✓Rich in eye-protective lutein and zeaxanthin
✓Linked to slower age-related cognitive decline
✓Very low calorie, high water and folate
✓Associated with lower cardiovascular disease risk
Dosing & Compounds
Typical Dose
Standard serving: 1 cup shredded, raw (47 g). Eat whole (with skin where edible); favour whole fruit over juice.
High in vitamin K (about 48 ug per cup), which can interfere with warfarin and similar anticoagulants — keep intake consistent if on these drugs. Leafy greens including romaine have been recurrent sources of E. coli and Listeria outbreaks, so wash thoroughly and observe recalls. Oxalate content is low to moderate. Otherwise very well tolerated. Educational only — always check with your doctor or pharmacist before combining Romaine Lettuce with any medicine.
Romaine Lettuce is most often taken for Supports blood-pressure regulation via dietary nitrate, Rich in eye-protective lutein and zeaxanthin, Linked to slower age-related cognitive decline, Very low calorie, high water and folate. A crisp, ultra-low-calorie leafy green delivering outsized vitamin K, vitamin A, folate, and the eye-protective carotenoids lutein and zeaxanthin.
Does Romaine Lettuce work — what does the evidence say?
Moderate evidence. Several controlled trials; effects real but modest or context-dependent. Romaine is a nutrient-dense, water-rich leafy green: a single shredded cup is roughly 8 kcal yet supplies meaningful vitamin K, provitamin-A carotenoids, and folate. As one of the higher-nitrate leafy greens, it shares the bioactive profile (dietary nitrate, lutein/zeaxanthin, vitamin K, folate) tied in human studies to lower cardiovascular risk, slower cognitive decline, and reduced progression of age-related macular degeneration. The strongest randomized evidence is indirect, coming from inorganic-nitrate and lutein/zeaxanthin trials rather than romaine itself; whole-diet leafy-green data are observational but consistent.
What is the typical dose of Romaine Lettuce?
Standard serving: 1 cup shredded, raw (47 g). Eat whole (with skin where edible); favour whole fruit over juice.
Is Romaine Lettuce safe? Any cautions or side effects?
High in vitamin K (about 48 ug per cup), which can interfere with warfarin and similar anticoagulants — keep intake consistent if on these drugs. Leafy greens including romaine have been recurrent sources of E. coli and Listeria outbreaks, so wash thoroughly and observe recalls. Oxalate content is low to moderate. Otherwise very well tolerated.
How many studies support Romaine Lettuce?
NutriDex cites 8 sources for Romaine Lettuce, graded "Moderate".
Cite this page
APA
Peh, D. (2026). Romaine Lettuce: Benefits, Dosage, Side Effects & Evidence. NutriDex — The Supplement Research Compendium. Retrieved 16 Sept 2026, from https://nutridex.info/s/romaine-lettuce
BibTeX
@misc{nutridex_romaine_lettuce,
author = {Peh, Daryl},
title = {Romaine Lettuce: Benefits, Dosage, Side Effects \& Evidence},
year = {2026},
howpublished = {NutriDex --- The Supplement Research Compendium},
url = {https://nutridex.info/s/romaine-lettuce},
note = {Reviewed by Dr Daryl Peh, MBBS Singapore, MMed FM. Accessed 2026-09-16}
}
For medical claims, citing the underlying primary studies linked above is preferred. NutriDex is an educational reference, not medical advice.