Most people have a favorite apple variety—maybe yours is McIntosh, Jonagold, or Granny Smith—but all apples have some important things in common: vitamins, minerals, fiber, and polyphenols. Apples contain vitamin E and potassium—nutrients that are especially important for heart health. They also have small but notable amounts of B vitamins and calcium. Their fiber, which includes both insoluble fibers like cellulose and soluble fibers like pectin, makes them a prebiotic food, helping to support healthy colonies of friendly gut bacteria. Pectin is reported to have cholesterol-lowering and blood sugar-stabilizing effects as well. Apples also have plant chemicals known as polyphenols, which are found mainly in the peels. Polyphenols provide apples with their color and flavor and protect the fruit from light damage, fungi, and insects. When we eat whole, unpeeled apples, their polyphenols act as antioxidants that contribute to many of apples’ health benefits.

Source: Nutrients