Canned foods have the advantages of long shelf life, durability and ease of distribution. Canned foods high in vitamin A and such as carrots, sweet potatoes, and tomatoes, protect the the body's cells and improve night vision. Canned tomatoes have high levels of lycopene, which helps prevent prostate cancer. Canned fruits and vegetables use no chemical preservatives, but are preserved via natural heat methods. We can reduce losses of vitamins during storage by storing the cans in a cool place.