DrFeb
Health Guide

lettuce

Lettuce is far more than just a crunchy base for your salad; it is a nutrient-dense leafy green packed with essential vitamins, minerals, and hydration. While often categorized as a dietary supplement source (especially for extracts like lactucarium), its true power lies in eating the whole leaf. Rich in Vitamin K, Vitamin A, and folate, lettuce supports bone health, vision, and cellular function. It is a low-calorie powerhouse that delivers significant health benefits with almost no downside, making it a staple for anyone looking to improve their diet naturally.
Evidence BasedDietary Supplement
lettuce
VERIFIED SOURCE

Bio-Activity Analysis

Nutrient Density Comparison (Vitamin K)

SCIENTIFIC DATA VISUALIZATION

Y-Axis
% Daily Value per Cup
Vegetable →

Health Benefits & Sources

Why You Need It

  • Bone Health: Essential Vitamin K helps bind calcium to your bones.
  • Hydration: Composed of over 90% water, it keeps you hydrated.
  • Eye Protection: Contains beta-carotene (Vitamin A) for healthy vision.
  • Improved Sleep: Contains lactucarium, known as 'lettuce opium,' which aids relaxation.

Deep Dive

Lettuce is a nutritional stealth weapon. While Iceberg is popular for crunch, darker varieties like Romaine and Arugula offer superior nutrient density. Vitamin K is the star player here; without it, calcium cannot be properly utilized by the body, leading to weaker bones. The antioxidants found in red and green lettuce, specifically lutein and zeaxanthin, accumulate in the retina, filtering harmful blue light and reducing the risk of macular degeneration. Finally, the high water content aids digestion and keeps your skin looking plump and healthy.

Natural Food Sources

Lettuce is the primary source, but other greens offer similar benefits.

FoodAmount% DV (Vitamin K)
Romaine Lettuce1 Cup (Shredded)~60%
Spinach1 Cup (Cooked)~740%
Kale1 Cup (Raw)~680%
Turnip Greens1 Cup (Cooked)~530%

Supplementation

While you rarely 'supplement' with lettuce directly, Lettuce Extract (often derived from wild lettuce) is available as a supplement for sleep support. However, eating the vegetable is superior for general health. Aim for 2 cups of leafy greens daily. If taking blood thinners (warfarin), keep your intake consistent.

Top Food Sources

Romaine Lettuce
Best for salads and sandwiches
Spinach
Excellent source of Iron
Arugula
Peppery flavor, high in nitrates
Butter Lettuce
Soft texture, good for wraps
Wild Lettuce
Used in extracts for sleep (Not for raw eating)

Frequently Asked Questions

No! While it has fewer vitamins than Romaine, it is still high in water and fiber and provides Vitamin K. It is great for hydration.
Yes. It is low in calories and safe to eat daily. Variety is best, but daily lettuce is a healthy habit.
It is a milky sap (lactucarium) found in wild lettuce and to a lesser degree in common lettuce. It has mild sedative properties.
Vitamin K and A are heat-stable, but some Vitamin C may be lost. Eating a mix of raw and cooked greens is ideal.

Safety & Side Effects

Safety Profile

Whole Lettuce: Extremely safe. The only risk is foodborne illness (like E. coli), so wash thoroughly. Wild Lettuce Extract: Do not confuse dietary lettuce with wild lettuce supplements. Wild lettuce contains lactucarium and can cause dizziness, sweating, or blurred vision in high doses. Pregnant women should avoid wild lettuce supplements entirely.

Scientific References

  • [1]USDA FoodData Central: Raw Lettuce, Romaine
  • [2]Harvard T.H. Chan School of Public Health: The Nutrition Source - Vitamin K
  • [3]Journal of Agricultural and Food Chemistry: Antioxidant properties of various lettuce cultivars