Q; Are Grits Good For You? A: Yes!*
*If They are Whole-Grain!
As you might guess, this topic is actually a fairly complex one. IF the grits are whole grain (a rather imprecise term) they are really good for you. Not all grits are whole-grain, but most mills manufacturing whole-grain products will be sure to mention it on their product labeling. Whole-grain (or specifically in the case of corn, whole-kernel) means that the grain has been ground or otherwise processed in a way that leaves a significant portion of the components of the grain in whatever product is in question. This includes the bran, germ, and endosperm of the grain or grains in the final product.
It doesn't really matter if the grits are stone-ground. To harness the healthy aspect of grain (be it corn or any other grain) a portion of the entire kernel, berry, or groat must be in the final product. These various parts of the seed contain complex carbohydrates that your digestive system needs to maintain a healthy metabolism. Without these complex carbohydrates, all that is left are the refined carbohydrates: the infamous "white starches" that essentially behave like sugar in your body. And sugar is really, really bad for you. Whether it is sugar or refined grain products, the glycemic index is high, leading to a spike in blood sugar and an array of deleterious health effects.
The sugar industry notoriously shifted their blame in the American obesity crisis to dietary fat. An NPR article is linked here.
But why is all the other stuff in grain so good for you? The answer is resistant starch. Resistant starch provides the microfauna in your digestive system to thrive by essentially providing them with food to ferment. All of the good bacteria and other microorganisms you should be getting by eating fermented foods like sauerkraut, kimchee, and yogurt need a lot of the fibrous whole-grain starch available in goods like grits and oatmeal to thrive.
The microbiome in the human body is an extortionary new field of scientific research. The interplay between ourselves and the microorganisms that make up a significant part or the pile cells we call ourselves is profound and the implications are mind-boggling. Here is a link to an article on the topic from the NIH.