WARNING!
This is an older article that may not reflect Dr. Mercola’s current view on this topic. Use our search engine to find Dr. Mercola’s latest position on any health topic.
By Dr. Mercola
Apples are the second most popular fruit in the US (bananas are the first),1 with each American eating about 19 pounds a year. 2
Undoubtedly, many of those apples are consumed right now, during the fall, which is peak season for apples in the US. This is one sweet treat that you can feel good about eating, too, as apples are packed with disease-fighting vitamins, antioxidants and more, easily making them one of the top-ranked fruits for your health.
Apples Ranked Second Highest for Antioxidant Activity
Compared to other commonly consumed fruits in the US, apples ranked second for highest antioxidant activity. However, they ranked highest for the proportion of free phenolic compounds, which means they are not bound to other compounds in the fruit and therefore may be more easily absorbed into your bloodstream.3
Notably, much of apples' antioxidant power is contained in the peel, where you'll find antioxidants like catechin, procyanidins, chlorogenic acid, ploridizin and more. According to the New York Fruit Quarterly:4
"Since apples are so high in antioxidants, it is no surprise that apples, specifically, are associated with a decreased risk of chronic disease.
Three studies have specifically linked apple consumption with a decreased risk for cancer… [and] a study has shown that apple and pear consumption has been associated with a decreased risk of asthma.
Apple consumption has also been associated with a decreased risk of coronary heart disease… [and] a reduced risk of Type II diabetes was associated with apple and berry consumption in another major Finnish study.
In the laboratory, apples and the compounds in them have properties that may explain their effects in protecting against disease. Our lab has found that apples, and especially apple peels, have powerful antioxidant activity and can greatly inhibit the growth of liver cancer and colon cancer cells.
Based on results from all of these studies, it appears that apples may play a significant role in reducing the risk of a wide variety of diseases."
I have four apple trees where I live in Chicago but hadn't eaten that many of them. After reviewing this information, I think I will be consuming more next year, as the harvest season just finished for this year.
An Apple a Day to Keep 5 Chronic Diseases Away?
A wealth of research suggests that eating apples may impact your health in a number of beneficial ways:5
• Brain Health: Apples have been found to protect neuron cells against oxidative stress-induced neurotoxicity and may play an important role in reducing the risk of neurodegenerative disorders, such as Alzheimer's disease.6
• Stroke: Eating apples is linked to a decreased risk of stroke.7
• Diabetes: Three servings of apples (and other fruits, such as blueberries and grapes) is linked to a 7 percent lower risk of type 2 diabetes.8 This may be due to their beneficial role in blood sugar regulation, as apples contain compounds that may:9
• Lessen absorption of glucose from your digestive tract
• Stimulate beta cells in your pancreas to secrete insulin
• Increase uptake of glucose from your blood by stimulating insulin receptors
• Cancer: Apples have a number of properties that may help reduce the risk of cancer, including antimutagenic activity, antioxidant activity, anti-inflammatory mechanisms, antiproliferative and apoptosis-inducing activity, as well as "novel mechanisms on epigenetic events and innate immunity." According to the journal Planta Medica:10
"Apple products have been shown to prevent skin, mammary and colon carcinogenesis in animal models. Epidemiological observations indicate that regular consumption of one or more apples a day may reduce the risk for lung and colon cancer."
• Heart Disease: Eating apples is associated with a lower risk of death from heart disease, an association that's thought to be related to their content of antioxidant flavonoids.11
Eat Whole Apples for the Most Health 'Bang' for Your Buck
While applesauce and apple juice do contain some valuable vitamins and antioxidants, eating apples in their whole form will give you the synergistic blend of nutrients and fiber the way nature intended. This is important for a number of reasons. For instance, apples are often thought of as a high-fiber food and many of its heart health benefits are linked to a type of fiber called pectin.
In reality, apples really only contain about two to three grams of fiber per ounce, of which pectin accounts for about half. Even though this is a modest amount of pectin, it has a powerful impact on your health because of its interactions with other apple phytonutrients. It can also help increase your fiber intake, which ideally should be 50 grams per 1,000 calories consumed. As explained by the World's Healthiest Foods:12
"… this relatively modest amount of pectin found in whole apples has now been shown to interact with other apple phytonutrients to give us the kind of blood fat lowering effects that would typically be associated with much higher amounts of soluble fiber intake.
In recent comparisons with laboratory animals, the blood fat lowering effects of whole apple were shown to be greatly reduced when whole apples were eliminated from the diet and replaced by pectin alone.
In summary, it's not fiber alone that explains the cardiovascular benefits of apple, but the interaction of fiber with other phytonutrients in this wonderful fruit. If you want the full cardiovascular benefits of apples, it's the whole food form that you'll want to choose. Only this form can provide you with those unique fiber-plus-phytonutrient combinations."
Similarly, research shows that eating a whole apple before a meal may lead you to eat 15 percent fewer calories – an effect that was not associated with applesauce or apple juice.13 Eating a whole apple was also linked with greater feelings of satiety after a meal.
Some People May Need to Eat Apples in Moderation
The other variable we haven't yet covered is fructose, a type of sugar that is linked to many chronic health problems when consumed in excess. I believe most will benefit from restricting their fructose to 25 grams a day, and as little as 15 grams a day if you have insulin or leptin resistance.
This includes fructose from whole fruits like apples. Apples are a relatively high-fructose fruit, with 9.5 grams in a medium-sized apple. Apple juice will contain considerably more, which is another reason why you're better off eating apples in their whole form.
It is also important to time your eating of fructose-rich foods like apple correctly. One of the tricks that I personally use is to time my fruit intake. Eating one after a calorie-rich meal for 'dessert' will not have the same effect as if you eat it after a glycogen-depleting workout.
In the former case, the apple's fructose is more likely to contribute to weight gain and insulin resistance; in the latter case, it will harmlessly replenish your glycogen stores within your muscles or be burned directly during your workout. I have actually been able to lose weight by increasing my fruit intake in this fashion. This works far better if you are metabolically adapted to burn fat as your primary fuel.
If you're insulin or leptin resistant (are overweight, diabetic, hypertensive, or have high cholesterol), which includes about 80 percent of Americans, then it would be advisable for you to limit your fruit intake to about 15 grams per day, which would be equivalent to eating approximately one apple and a handful of blueberries -- unless you timed the fruit consumption as described above and were doing fairly significant exercise in which you were burning a few hundred calories.
If you are not insulin/leptin resistant, (are normal weight without diabetes, hypertension or high cholesterol) and regularly engage in strenuous physical activity or manual labor, then higher fructose intake is unlikely to cause any health problems. In this case, you can probably eat more fruit without giving it much thought.
What Else Should You Look for in an Apple?
Because much of the antioxidant content of an apple is found in its peel, you'll want to leave the peel on when you eat it. For this reason, look for organic apples, which will be free from pesticides and other chemicals. Apples are one of the most pesticide-contaminated fruits there is,14 so if you're planning to eat more apples, make them organic. If you purchase conventional apples, briefly soaking them in a solution of 10 percent vinegar to 90 percent water may help to remove some pesticides (and bacteria).
But keep in mind that many pesticides are lipophilic, and are therefore capable of entering through the surface of conventional produce deep into the flesh of the fruit or vegetable within minutes. If you have your own apple trees, you can integrate high-performance agriculture techniques that will radically increase the nutrient content and also virtually eliminate any diseases that the apples might be acquire. When it comes to choosing an apple, the Washington State Apple Commission recommends:15
- Choosing an apple with shiny, not dull, skin (dull apples will not be crisp)
- Firm apples free from bruises and punctures
- Refrigerating apples at 39 degrees F to maintain crispness
- Protecting cut apples from browning by dipping them into a solution of one part citrus juice to three parts water
If you're looking for even more apple facts and nutrition information, be sure to check out our apple food facts page.