If you’re talking about an oncologist or a cardiologist, maybe. Eating high-fiber, high-antioxidant fruits like apples has been shown to reduce the risk of cancer and heart disease.

“Obviously, the saying isn’t literally true,” says Lynne Brown, R.D., an associate professor of food science at Pennsylvania State University, in State College; otherwise doctors would be out of business. “But the sentiment is what counts — eat more fruit.” Her advice: Opt for a variety of fruits rather than sticking to one favorite. That way, you’re sure to get the widest possible spectrum of cancer-fighting micronutrients and vitamins.

If you are eating just one serving of fruit a day, though, make sure it’s dark red or purple — a plum, blueberries, or red grapes, for example. “They contain higher amounts of phytochemicals than other fruits,” says Brown. “These phytochemicals help sop up the free radicals that may cause bodily damage like cancer and heart disease.”