In Greek mythology, apples were associated with the healing god Apollo, perhaps the source for the modern-day adage that an apple a day keeps the doctor away. In medieval times, physicians were taught that cooked apples could relieve disturbances of the bowels, lungs and nervous system. The custom of serving fresh fruit, particularly apples, at the end of a meal arose because of the favorable effects on digestion attributed to them by the physicians Hippocrates and Galen. Plus apple juice was one of the earliest prescribed antidepressants.
Apples are not bursting with vitamins and minerals like other fruits, though they do provide a bit of vitamin C and potassium. However, without a doubt apples are amazing for controlling blood sugar, says Dr. Barry Sears in his book The Top 100 Zone Foods. “Apples are a good source of soluble fiber, especially pectin, which helps control insulin levels by slowing the release of sugar into your bloodstream. Pectin also helps reduce cholesterol levels by lowering insulin secretion.”
We now also know that apples fairly shine in antioxidant phytochemicals; the principal ones identified so far are phenolics and the flavonoid quercetin.
Research suggests that natural antioxidants like these could be even more effective than vitamin supplements. Comell University researchers, for example, have found that the amount of fresh apple extract from a medium apple with skin provides the antioxidant activity equal to 1,500 milligrams of vitamin C. Using colon cancer cells treated with apple extract, the scientists found that cell proliferation was inhibited in vitro. The researchers also tested the apple extract against human liver cancer cells and again found inhibition of the growth of those cells.
People who eat lots of apples may have lower rates of lung cancer, judging by a study done in Finland. The study, published August 1, 1997, in the American Journal of Epidemiology, was focused on flavonoids. The study reviewed the diet of 9,959 Finns aged five to 99 years. Of those in the group who were cancer-free in 1965, those who ate the most flavonoid-rich foods – apples and other fruit, onions, juices, vegetables, and jams – had a 20 percent lower incidence of cancer through 1991. Quercetin, a flavonoid found mostly in apples, accounted for 95 percent of the flavonoids consumed by the study group.
To get the most benefit, don’t peel your apples. Quercetin is found only in the skin.