In the united states and even most other industrialized countries, cancer and cardiovascular disease are the two main causes of death. The causes of which have both been linked to lifestyle choice - the most important being diet. Studies have estimated that about 30 percent of all cancers could be prevented by a healthy diet. Obesity, diabetes, and high cholesterol are costing the US billions in health related expenses that could be reduced and avoided by influencing citizens to maintain a healthy diet and lifestyle.

Researchers examined over a hundred studies relating to cancer and diet; out of 156 studies 128 showed that vegetables and fruits had a protective effect against several different forms of cancer. Studies showed that people who consumed lower amounts vegetables and fruits were twice as likely to get cancer compared to people who consumed higher amounts of them.

Most of the protective benefits of vegetables and fruits has been found to lie in the phytonutrients. Compounds such as flavonoids, isoflavonoids, phoenolic acids, and carotenoids. In a Finnish study, flavonoid intake had been associated with an incidence of lower total mortality. One of the main sources of that study for dietary flavonoids that happened to show the strongest association with a lower mortality was apples.

Apples are a great source of antioxidants. In a comparison of commonly eaten fruits in the US, apples ranked second highest in terms of the level of antioxidants. Apples also had the highest portion of free phenoics in comparison to other fruits. Meaning that these compounds are not bound to others in the fruit and can therefore be more available for eventual absorption into the bloodstream.

Apples contain a variety of phytochemicals including catechin, phloridzin, quercetin, and cholorogenic acid. All of these phytochemicals are considered to be very strong antioxidants. The phytochemical composition of apples do vary between the different varieties of apples. While storage doesn't affect the phytochemicals of apples, processing them can affect them greatly.

The phytonutrients found in apples can actually help to regulate the blood sugar. Studies have shown that poyphenols in apples can even prevent spikes in blood sugar. Some of the flavonoids found in them, such as quercetin, can inhibit enzymes like alpha-glucosidase and alpha-amylase. Enzymes like these are what help to breakdown complex carbohydrates into simple sugars. Since your blood sugar has less simple sugars to deal with it helps to keep it at normal levels.