A number of nutrition studies have proven that pectin helps reduce cholesterol. Early research indicates that D-glucaric acid, an ingredient in apples, may be a natural regulator of cholesterol. A diet rich in D-glucaric acid can help reduce damaging LDL by up to 35 percent. There is growing evidence that eating apples may help prevent lung cancer. The National Cancer Institute has reported that foods containing flavonoids like those found in apples may reduce the risk of lung cancer by as much as 50 percent.
Apples have the highest concentration of flavonoids of any fruit.
A Cornell University study found that phytochemicals from the skin of an apple inhibited the reproduction of colon cancer cells by 43 percent. These findings supported earlier research that indicated antioxidant flavonoids appeared to reduce the incidence of lung cancer. A British study of Welsh men indicated that people who eat at least five apples per week experience better lung function. It's not clear why apple eaters could breath more easily, but researchers believe antixidants contained in apples may ward off disease by countering oxgen's damaging effect on the body. A Finnish study published in 1996 showed that people who eat a diet rich in flavonoids have a lower incidence of heart disease.