Apples are free of fat, sodium and cholesterol, contain about 17 percent of the daily recommended intake of fiber and 11 percent of the daily recommended intake of vitamin C. Apples contain 80 to 95 calories in average-sized piece of fruit. Two-thirds of the fiber in an apple is found in the peel, alongside many antioxidants that help to reduce cellular damage in the body.
Apples contain an array of polyphenols that have a variety of health benefits. Phytonutrients slow down carbohydrate digestion and help to regulate blood sugar using three different mechanisms: the absorption of glucose from the digestive tract is lessened; the pancreas’ beta cells are stimulated to secrete insulin; and insulin receptors are stimulated to increase uptake of glucose from the blood. Apples also alter the amounts of two types of bacteria in the digestive tract, providing positive metabolic changes in the large intestine and improving the overall health of the gastrointestinal system.
Most polyphenols in apples function as antioxidants. Liquid peroxidation of blood vessel membranes is the primary risk factor for atherosclerosis, so antioxidants decrease the risk of many chronic heart problems. Strong antioxidant benefits are linked to a lower risk of asthma, and apples contain quercetin, which has anti-inflammatory properties that reduce risk factors for cardiovascular diseases. The combination of antioxidant and anti-inflammatory properties may mean that apples may reduce the risk of lung cancer. Research also links applies to various degenerative conditions.