Will an apple a day keep the doctor away? It appears there may be a lot of merit to this statement. The health benefits of eating a daily apple have been known for a long time but mainly because it is a fresh, fibrous fruit. In the last five years, apple research in regards to health has been at an all time high, primarily in regards to the level and type of polyphenols found in apples.
Apples are the pomaceous fruit of the tree, Malus domestica, which is part of the rose family. The tree originated in Western Asia and more than 7500 cultivars are known today. China is the largest worldwide producer with the US coming in second, followed by Iran, Turkey, Russia and India.
Apples must cross-pollinate in order to produce fruit which is facilitated mainly by honey bees. Mature trees typically produce up to 450 pounds of fruit yearly. Commercially, apples can be stored for months in temperature controlled chambers that delay the production of ethylene, a gas which induces ripening. At home, most varieties of apples can be stored in the refrigerator for up to 2 weeks without decline.
In the US, 11 cultivars or varieties account for 90% of what is sold in stores, compared to 300 varieties grown in 1858 in the US. Many of the varieties not readily available in stores are known as heirloom varieties. There are many groups forming to protect these varieties from extinction. One such group is AppleCorps out of Virginia’s Blue Ridge Mountains, headed by Diane Flynt.
Let’s go back to keeping the doctor away. One apple provides one fifth of a day’s requirement of fiber and the high complexity of its carbohydrates means it has a low glycemic index, so it is a good food for people watching their weight or blood sugar due to diabetes. Apples have been shown to slow carbohydrate digestion, reduce glucose absorption and stimulate insulin receptors thereby regulating blood glucose levels.
But the most important findings about apples are the antioxidant properties contained in the pulp and the peel. The primary phytonutrient, quercetin, found mainly in the peel, acts as an antihistamine and an anti-inflammatory agent. Quercetin has been shown to lower CRP levels which reflect possible inflammatory reactions in the vascular system related to increased risks for heart disease. The antioxidant properties of apples are thought to decrease oxidation of cell membrane fats (called lipid peroxidation) which is a strong risk factor for clogging of the arteries, which in turn leads to heart attacks and strokes. The antioxidant properties in apples have also been linked to reduced risks of lung cancer, asthma, macular degeneration and Alzheimer’s disease.
As with any component in food found to have a significant health benefit, it is better to eat the whole food and not try to supplement the compound. It is the synergy of the all the ingredients in the food that provides the benefit of that particular compound. In the case of the apple, it appears that the peel has the most important antioxidant properties, so wash and eat as it comes from the tree.
Nutrition information for an apple with skin:
1 large apple (223 g) – 116 calories
1 medium apple (182g) – 95calories
1 small apple (149g) – 77calories
1 extra small apple (101g) – 53calories
Apples are primarily water, with a good amount of fiber, Vitamin C and potassium.