Leafy greens linked to 16% lower rate of COPD and better lung health

A large study of 179,000 UK Biobank participants found that people with highest vitamin K1 intake (from leafy greens like spinach and kale) had a 16% lower rate of COPD compared to lowest intake, and better lung function measured by spirometry tests.

This was observational research showing association, not direct causation; people who eat more greens may also exercise more, smoke less, or have other healthy behaviors that lower disease risk.