“You’ll find these powerhouse phytonutrients in leafy greens like spinach,” Felton says. Spinach is also rich in vitamin K and dramatically reduces inflammatory markers in the blood, according to the Arthritis Foundation. Spinach is also the kind of leafy green that alleviates pain from stomach ulcers. The fiber can help the ulcer heal faster and stop the formation of additional ulcers, the Royal Society of Chemistry, U.K.’s professional body for chemical scientists, says.