Kale

A single 100g serving of kale provides 200% of the RDA for vitamin K and 134% for vitamin C, earning it the highest nutrient-density score of any leafy green—35% denser than the typical spinach. Its glucosinolates and flavonoids have been studied for anti-inflammatory and cancer-preventive properties across multiple clinical trials, offering immune support unmatched by #1 blueberries' antioxidant focus.