Nutritionally speaking, unpeeled apples provide their most plentiful nutrients just under the skin. Apples are a good source of potassium,folic acid, and vitamin C. A medium apple, approximately 142 grams, has only 81 calories and 3.7 grams of fiber from pectin. It also supplies 159 mg of potassium, 3.9 mcg of folic acid, 7.9 mg of vitamin C, and 9.6 mg of calcium. Additionally, there are trace amounts of B vitamins, iron, magnesium, and zinc.

So since we are all undoubtedly familiar with the age old saying an apple a day keeps the doctor away, here's a quick glance at why this phrase is scientifically true? Here's a helpful hint, in order to get the maximum amount of benefit from your apple, don't substitute apple juice for apples. Though it contains some iron and potassium, apple juice contains little of the beneficial compounds quercetin and fiber. When you eat this fruit, you're not only satisfying your sweet tooth; you're also helping your body defeat disease.

• Anti Aging: Two new animal studies by researchers at the University of South Florida Center for Aging and Brain Repair and James A. Haley Veterans Hospital compared three groups of older rats and found that aged rats fed spirulina (a blue green alage high in antioxidants) or an apple enriched diet, demonstrated improved neuron function, a suppression of inflammatory substances in the brain, and a decrease in malondialdehyde (MDA), a marker for oxidative damage.
• Protects lungs: Apples contain high levels of antioxidant flavonoids called quercetin; they protect the lungs from harmful effects of atmospheric pollutants and cigarette smoke. The body produces an inflammatory reaction in response to foreign invaders, such as pollutants. This reaction releases highly reactive molecules known as free radicals, which cause damage to the tissue. Antioxidants work by mopping up these free radicals before they can cause damage.
• St. Georges Hospital Medical School in London found that eating five or more apples a week was linked to a slightly better lung function. Those who ate apples had a lung capacity 138 milliliter higher than those who did not. Research conducted by the University of Nottingham, United Kingdom, stated that eating 5 apples per week or at least three tomatoes reduced the risk of wheezing associated with asthma and lung function. Steamed apples sweetened with honey are beneficial for a dry cough and may help to remove mucous from the lungs.
• Cancer: The apple skin itself contains 4 milligrams of quercetin, which is helpful in preventing cell changes that can lead to cancer. Phytonutrients in the skin of apples inhibit the growth of colon cancer cells by 43%. m Flavonoids in apples may reduce the risk of lung cancer by as much as 50%. One study, conducted in Finland at the National Public Health Institute, found that diets with the highest intake of phytochemicals from apples were associated with a 46 % reduction in the incidence of lung cancer.
• Heart Disease: Phytonutrients decrease the risk of heart disease. A recent University of California-Davis study found that two apples a day reduced the damaging effects of the LDL cholesterol ("bad cholesterol"), thus promoting cardiovascular health. High consumption of quercetin is associated with the lowest risk of dying from ischemic heart disease .High apple consumption was associated with reduced risk of thrombotic stroke, a type of stroke where a blood clot starves part of the brain of oxygen.
• Diabetes: Apples abundant quantity of pectin is an aid in reducing high cholesterol as well as blood sugar, a wonder food for people with coronary artery disease and diabetes. Pectin is a substance that helps regulate blood sugar and thus prevents a sudden increase, or drop, in serum sugar levels.
• Digestion: The malic and tartaric acids in apples inhibit fermentation in the intestines. Their high fiber content adds bulk that aids the digestive process, making elimination natural and comfortable. Pectin, a soluble fiber, encourages the growth of beneficial bacteria in the digestive tract.