California produces the most grapes in the United States with Washington state following. The most popular types of green grapes are Thompson Seedless and Perlette. Thompson Seedless grapes lead all other table grapes in quantities shipped and are the primary variety for making raisins. Grapes do not ripen after being harvested unlike some other fruits. A serving size of grapes is one and one-half cups, which contains 90 calories and has no saturated fat, cholesterol or sodium.
Grapes contain resveratrol, a phytochemical, that prevents cancer.
Grapes are also packed with flavonoids, including quercetin, anthocyanin and catechin, which prevent heart disease by preventing the formation of blood clots. While all fruits and vegetables contain phytochemicals, they will not have the same kind or amount. The research on phytochemicals and their importance in health is still emerging. This increases the importance of eating a variety of fruits and vegetables every day to take advantage of the known nutritional components plus the benefits of phytochemicals.