What we want from green veggies is chlorophyll. Chlorophyll rids the body of environmental toxins, heavy metals, herbicides, and pesticides.
Make sure you get lots of green things in your diet -- leafy greens, broccoli, cucumbers, celery, sprouts, dandelion teas, chlorella supplements... whatevs. Aiding in detox, increasing oxygen content, and purifying the blood, greens are the essential building blocks of any healthy and vibrant diet. (Plus, they make you glow. I'm serious.)