Vegetables, Fruits, Cancer
Numerous early studies revealed what appeared to be a strong link between eating fruits and vegetables and protection against cancer. But because many of these were case-control studies, where people who already have a certain health ocase are compared to people who do not have that controls it is possible that the results may have been skewed by problems inherent in these types of studies; people with illnesses, for example, often recall past behaviors differently from those without illness, which can lead to potential inaccuracy in the information that they provide to study investigators.