There’s no healthiest leafy green—eat a mix for best nutrition

There’s no single healthiest leafy green; nutrient density varies and watercress is notably rich per calorie, but variety is best: darker greens tend to be richer in nutrients while lighter greens still provide fiber, hydration and vitamins. To maximize absorption of fat-soluble vitamins, pair greens with healthy fats and consider cooking. For safety, heat greens to about 160F to reduce pathogens and wash thoroughly; storage matters—whole greens stay fresh 1–2 weeks, and storing unwashed can extend life. In short, eat a mix of greens to get a broad nutrient profile and lower disease risk.