Can certain foods help treat fatty liver?

Usually yes; ask Dr. A person with mild fatty liver likely has gotten extra fat in most other places in the body, and probably is eating more sugar and plain carbs than he should be. First of all, exercise, weight loss, and a low sugar and low carbs diet can help. He should also work with his primary care doctor to see if he needs medication or further testing, as there can be other problems, such as high cholesterol.
No. Reducing your fat intake, losing weight, cutting back on alcohol, and controlling other illnesses like diabetes or cholesterol will help with fatty liver. It's all about diet - no specific food will do that - at least none that you can sustain for a lifetime.