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Leafy Greens

Leafy greens as functional foods: observational meta-analyses on cardiovascular disease and lutein, and the warfarin vitamin K caution.

Content last updated . This page has not been medically reviewed.

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Overview

Leafy greens include spinach, kale, lettuce, collards and chard. They are a source of lutein and vitamin K.

What the research shows

  • A meta-analysis of 17 cohort studies found green leafy vegetable intake was associated with lower incident cardiovascular disease (pooled RR 0.93, 0.92 to 0.95). [1]
  • A review of 24 meta-analyses found that each 100 g a day of leafy greens was associated with about 25% lower risk of all-cause mortality, coronary heart disease and stroke, and that lutein intake was inversely associated with age-related macular degeneration. [2]

These are associations from observational studies; people who eat greens differ in many ways. Proper evidence from trials of disease prevention was not found.

Safety: warfarin

Leafy greens are a major source of vitamin K. Patient-education pages advise people on warfarin to keep vitamin K intake consistent rather than avoid greens, and to tell their anticoagulation clinic before big changes. [3]

Other considerations

  • Wash raw leaves and, if pregnant, follow food-safety guidance. [4]

Related

Cruciferous vegetables · Natto

Frequently asked questions

Should I avoid spinach on warfarin?

Not necessarily; keep intake consistent and ask your clinic. [3]

References

  1. Ojagbemi A et al. Dietary intakes of green leafy vegetables and incidence of cardiovascular diseases. Cardiovasc J Afr 2021. PMID 34128951.
  2. Li N et al. Green leafy vegetable and lutein intake and multiple health outcomes. Food Chem 2021. PMID 34034049.
  3. Cedars-Sinai. For Warfarin: Eating a Consistent Vitamin K Diet. Patient education page; ask your anticoagulation clinic for your own plan.
  4. Clemson Cooperative Extension. Food Safety for Pregnant Women and Their Babies. Extension fact sheet.
Education, not medical advice. This page is for general information. It does not diagnose or treat any condition and is not a substitute for care from a qualified health professional. Natural does not automatically mean safe. Ask a clinician or pharmacist before changing your care, especially if you take medication, are pregnant or breastfeeding, or have a health condition.