Amy Batal, PhD Responds:

Amy Batal, PhD, assistant professor of poultry nutrition at the University of Georgia, responds: While many people believe that brown eggs are healthier than white eggs, the color of the shell has nothing to do with quality or nutritional value. Egg color is determined by the breed of the hen. Breeds with white earlobes lay white eggs, while breeds with red earlobes lay brown eggs. 

Consumer preference drives the demand for egg color: Americans prefer their eggs white, which is why you'll see row after row of white eggs at the supermarket. Europeans, however, favor brown eggs. What's more important than egg color is freshness. Eggs will keep for up to five weeks, but their quality declines with time. To enjoy the best flavor at home, use eggs that are less than a week old for baking, poaching, or frying. Eggs that are more than a week old are best for deviled eggs and hard-boiled eggs--shells peel easier off older eggs.