In most studies, eating more vegetables and fruits has been linked with a lower risk of lung, oral (mouth), esophagus (tube connecting the mouth to the stomach), stomach, and colon cancer. But few studies have been done on whether a diet that includes many vegetables and fruits can reduce the risk of cancer coming back (recurrence) or improve survival. Some recent studies suggest that a higher intake of vegetables may have a helpful effect on recurrence or survival for breast, prostate, and ovarian cancers, but this is not definite.
Still, cancer survivors should get at least 2 to 3 cups of vegetables and 1½ to 2 cups of fruits each day because of their other health benefits. It’s not known which of the compounds in vegetables and fruits are most protective, so it’s best to eat different kinds of colorful vegetables and fruits each day.