Emphasizing local grown foods and foods in season is beneficial. Additionally, keep in mind that other than modern man's increased use of brain function, genetically we are not much different from our ancestors 10,000 years ago in terms of what our bodies "expect" and require to meet nutritional requirements. From an evolutionary perspective, our bodies are not prepared/designed to handle the enormous and very recent onslaught of man-made/man-altered foods. So, a good rule of thumb in food purchasing and selecting is that if your ancestors 10,000 years ago didn't eat a food, you shouldn't either. Translated: Eat only whole, natural, unaltered foods as much as possible.