The key nutrients which prevent disease in produce, including apples, are known as phytochemicals or phytonutrients.
Phytonutrients are substances which a plant naturally contains to protect it against sunlight, oxidation from air, pollution, and bacteria or viruses. Once we eat these plants, our immunity increases and we are more resistant to diseases such as cancer and heart disease. Scientists estimate there are over 100 phytochemicals in one serving of fruits or vegetables and there may be as many as 13,000 different phytonutrients in our food supply.
Polyphenols are the new hot topic in research studies and are a type of phytonutrient. A group of polyphenols called flavonoids have antioxidant activity and are known for prevention of heart disease and cancer, since they can lower cholesterol levels and inflammation in the body.
Apples contain a polyphenol known as quercetin, which is thought to lower LDL cholesterol and decrease plaque in the arteries. They also contain pectin, a type of fiber which can lower cholesterol.
A food scientist from Cornell University, Rui Hai Liu, did extensive research on apples and found they contain substances which fight cancer cells and reduce the number and size of tumors in rats. He also stated that apples contain another compound known as triterpeniods in the peel, which can inhibit or kill cancer cells.
It is important to eat the whole apple, since the key nutrients are in the peel and the interior. So the old adage of “an apple a day keeps the doctor away” may be more apropos than we moderns ever realized. The one disclaimer for those with insulin resistance is to watch the size of your apples since the standard grocery store type can be significantly larger than nature intended.