An Apple a Day Cuts Diabetes Risk by 28% and Has Anticancer Effects
An apple a day really does keep the doctor away. Scientists have found that eating just one apple a day can lower your risk of diabetes by 28%.  But that’s not all.
Apples should be classed as a superfood when it comes to antioxidants. Two varieties in particular, Granny Smith and Red Delicious apples scored high when the USDA ranked 100 foods for antioxidant activity.  Vitamin C is an antioxidant necessary for at least 300 functions in the body including tissue growth and repair, collagen formation, protection against abnormal clotting and bruising, adrenal gland function, production of anti-stress hormones and interferon, and is necessary for the metabolism of folic acid, tyrosine and phenylalanine. Vitamin C may also reduce levels of low-density lipoproteins (LDL or “bad cholesterol”), while increasing levels of high-density lipoproteins (HDL or “good cholesterol”), as well as helping prevent atherosclerosis and lowering blood pressure. Vitamin C promotes healing of wounds and burns and may prevent the formation of cataracts. Vitamin C works synergistically with beta-carotene, vitamin E and zinc which is necessary for immune function and is important in prostate gland function.
Red apples contain a pigment in their skin that contains an antioxidant called quercetin. Recent studies have found that quercetin can help boost and fortify your immune system, especially when you're stressed out. Quercetin is found in many plants and foods, such as red wine, onions, green tea, apples, berries, Ginkgo biloba, St. John's wort, American elder, and others. Buckwheat tea has a large amount of quercetin. Quercetin is used for treating conditions of the heart and blood vessels including “hardening of the arteries” (atherosclerosis), high cholesterol, heart disease, and circulation problems. It is also used for diabetes, cataracts, hay fever, peptic ulcer, schizophrenia, inflammation, asthma, gout, viral infections, chronic fatigue syndrome (CFS), preventing cancer, and for treating chronic infections of the prostate. Quercetin is also used to increase endurance and improve athletic performance. Quercetin has antioxidant and anti-inflammatory effects which might help reduce prostate inflammation. Eating apple peels may also reduce join inflammation and increase mobility. 
Apples are high in potassium which have positive cardiovascular effects. Potassium is needed for a healthy nervous system, electrochemical impulses, and a regular heart rhythm. Potassium helps prevent stroke, aids in proper muscle contraction and works with sodium to control the balance of water in the body and helps maintain normal blood pressure.
Apples are high in a fiber called pectin. Scientists agree that a high fiber diet can help control weight and the risk of obesity as well as reduce irritable bowel syndrome which is characterized by constipation, diarrhea, abdominal pain and bloating. Eating more fiber can help reduce cholesterol, gallstones, and help detoxify the liver. 
Eating apples may also help prevent neurological disorders like Alzheimer’s and Parkinson’s disease and may reduce the risk of stroke. 
Apples contain a nutrient called phloretin (Ph) which is also found in pears and various vegetables. Phloretin is known to have antitumor activities in several cancer cell lines. In addition, pectin has also been found to trigger apoptosis in MDA-MB-231 human breast cancer cells and has potential to improve cancer treatment as a natural product. [10} Researchers found that chemicals in apple and berry juices called phenols inhibit the growth of colon cancer.  Other types of cancer found to respond to ingredients in apples are liver , melanoma , colorectal  and oral cancer .
Apples are inexpensive, low in calories and packed with nutrition and health benefits, all reasons to include them in our daily diet.
12. http://www.ncbi.nlm.nih.gov/pubmed/25256427 liver
13. http://www.ncbi.nlm.nih.gov/pubmed/25157464 melanoma
14. http://www.ncbi.nlm.nih.gov/pubmed/24074742 colorectal
15. http://www.ncbi.nlm.nih.gov/pubmed/23639509 oral