Locally produced food is helpful for health and the environment for a multitude of reasons.  Most likely, food grown locally is picked at the best time when it is the ripest, rather than needing to be picked early and shipped to a different place.  This transportation of the food also gives the food for a higher risk of contamination since there is a lot of time between consumption and harvest.  Also, food grown locally would taste better and have more nutrients, since the plants that are in season at that time are raised in the correct area and don't need to come from somewhere where it is in season, which it would have to be picked before it is fully ripened and fresh.  This food also benefits the environment, because the grown food supports the farmland in the area.   
http://msue.anr.msu.edu/news/7_benefits … ocal_foods