Yes its good -
http://www.nutritiondata.com/facts-C00001-01c20cF.html.
25 cals per 100 grams; a "good source of Thiamin, Calcium, Iron, Magnesium, Phosphorus and Potassium, and a very good source of Dietary Fiber, Vitamin C, Vitamin K, Vitamin B6, Folate and Manganese". Maybe not quite as good as spinach or brocolli (is 3.2% sugar and 1.5% fructose) but still good.
Why cook it though. Tastes better raw