Detox
Romaine Lettuce
A workhorse salad green that punches well above its watery reputation, delivering nearly a quarter of a day’s vitamin A in a single cup.
Vision
Gut Health
Detox
Serving
1 cup, shredded, raw (47g)
Calories Per Serving
8
Key nutrients
Vitamin A, vitamin K, folate, fiber
Nutrient density
389
Why it’s worth eating
Romaine lettuce is far more nutrient-dense than its crisp, watery reputation suggests, delivering meaningful vitamin A, vitamin K, and folate at almost no caloric cost. Its high water content also makes it one of the more hydrating leafy greens. Use it as a salad base, or grill whole halves for a smoky twist.
What you may notice
Visual comfort in low light
Digestive regularity
Markers worth tracking
Vitamin K and INR status
Vitamin A status
How to eat it
Tear rather than knife-cut close to serving time, cut edges brown faster and lose vitamin C more quickly.
Pairs well with
Healthy fats (olive oil, avocado), helps absorb the fat-soluble vitamins A and K
Pairing with vitamin C-rich vegetables, supports overall antioxidant activity in the meal
Storage
Refrigerate unwashed in its original packaging or a perforated bag; whole heads keep about a week, longer than pre-cut leaves.
The numbers, per 1 cup, shredded, raw (47g)
40%
Vitamin K
23%
Vitamin A
2%
Vitamin C
1%
Calcium
3%
Iron
2%
Magnesium
2%
Potassium
0%
Vitamin B12
0%
Vitamin D
Fiber
1.0g
Lettuce, cos or romaine, raw (FDC 169247)
Evidence
D
HONEST FLAG: essentially no clinical literature. Romaine is a hydration, fibre and folate vehicle rather than a bioactive powerhouse. The documented, citable story is food safety.
Study dose vs. serving
No established benefit dose.
CDC and FDA outbreak surveillance. The 2018 Yuma-region E. coli O157:H7 outbreak was the largest US O157:H7 outbreak since 2006.
Use caution if
You take warfarin or other blood thinners, moderate vitamin K content; keep intake consistent
You have a latex allergy, lettuce is a recognized cross-reactive food in latex-fruit syndrome
Details
Type
Fruits & Veg
Season
Spring and autumn (cool)
Forms
Fresh, hearts, bagged
Price
Budget
Bioactive
Lutein and zeaxanthin, folate, some nitrate
Heat stable
Partial
Watch
RECURRENT E. COLI O157:H7 OUTBREAKS: the 2018 Yuma outbreak caused 210 illnesses across 36 states, 96 hospitalisations, 27 haemolytic uremic syndrome cases and 5 deaths; the outbreak strain was found in Yuma canal water. Further outbreaks followed in autumn 2018 (62 illnesses) and October 2019 (23 illnesses). FDA counts 28 STEC outbreaks linked to leafy greens between 2009 and 2017. Bagged and pre-cut product has historically carried higher risk.
Reliability
3 / 5
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