How are beets good for you
But seriously, off the top of my head, they are very high in trace minerals, fibre, natural sugars. The leaves are very high in iron and Vit. K (which is essential for blood clotting so you don't bleed to death from a paper cut). And a bunch of other good stuff that I bet someone else here can give you in more detail.
Basically they are a really good food for cleansing toxins and for the cardiovascular system. I've often seen them included in anti-inflammatory diets.
Here's a wiki link with some decent citation if you want to learn more: http://en.wikipedia.org...