Diet and Nutrition: The Health Benefits of Apples

The old cliché exists for a reason: An apple a day benefits your whole body in multiple ways. One of the most widely grown and eaten fruits in the world, they come in more than 7,500 varieties. They are healthiest when you eat them fresh and whole (as opposed to pre-sliced, juiced, or as applesauce). A medium one has about 80 calories, 1 gram of protein, 19 grams of natural sugar, and zero fat, sodium, or cholesterol.

That's where apples store two-thirds of the fiber that keeps your digestive system on track. The shiny skin also holds lots of antioxidants, or natural substances that help protect your cells from some of the damage that may lead to cancer, heart disease, and stroke. If you're concerned about pesticides, give it a good wash before you sink your teeth into its sweet flesh.

Apples have more of the plant pigment quercetin than most other fruits and vegetables. This plant-derived chemical called a flavonoid protects cells throughout your body, including the ones in your brain. These fruits are also high in antioxidants that may help offset the memory loss caused by various types of damage to your cells. One small study suggested that apple juice improved the mood and behavior of people with moderate to severe Alzheimer's disease.

Flavonoids give apples their color, protect them from harmful elements in the environment, and repair damage to their skin and cells. These natural chemicals may be good for you, too. Quercetin, which can help brain cells, protected pancreas cells from cancer in lab studies and holds promise to help people, too. Research is ongoing.

Your pancreas plays a key role in processing the sugar in your bloodstream. The flavonoids in apples may help keep the cells in your pancreas healthy and able to perform this important job. That may help lower your risk for type 2 diabetes. In one 9-year study, people who ate one or more apples a day were 28% less likely to get type 2 diabetes than those who didn't eat them.

One medium apple with skin has 4.3 grams of fiber. This nutrient slows down your digestion and helps you feel fuller longer. These fruits also have a low glycemic load, which means they won't spike your blood sugar too high and trick you into thinking you're still hungry. These satisfying effects can keep you from snacking and help you maintain your weight.

One group of researchers found that people who ate at least one apple a day were a third less likely to get colon cancer than those who did not. The healthy helping of both fiber and flavonoids may help protect the lining of the intestines and keep the cells healthy.

Apples are a natural source of pectin, a soluble fiber that moves food through your digestive system and keeps you regular. Bonus benefit: Your good gut bacteria love to feed on pectin. Some experts think that pectin helps the good bacteria multiply, which may help ward off some chronic diseases and cancer in the gut.

In lab studies, the combination of plant chemicals, pectin, and fiber in apples helped protect heart and blood vessel cells from damage. The pectin and fiber can also help lower LDL or "bad" cholesterol that can build up in your arteries and lead to heart disease.

Apples, like other fruits and vegetables, have natural anti-inflammatory and antihistamine properties, which means they may help take a bite out of asthma and other breathing problems. One study of women who ate apples while pregnant showed that their children were less likely to have symptoms of asthma and wheezing by age 5. Some studies show that people who eat more fruits and vegetables are less likely to have asthma.

They can't compete with oranges, but apples have 10% of the vitamin C you need every day. That plus the soluble fiber you get from pectin makes this fruit a delicious defense against any germ that attacks your immune system. And if you do get sick, apples may even help you bounce back quicker.

For all its health benefits, one part of this fruit is forbidden -- in large quantities, that is. The seeds contain amygdalin, a compound that becomes cyanide in your body. If you accidentally eat a seed, it won't poison you -- your body can detoxify small amounts of cyanide on its own. You'd have to chew seeds from many apples at once very carefully to release enough amygdalin in your system to be harmful.