From World's Healthiest Foods
Apples
The warm scent and flavor of baking apples is a sure sign that fall is just around the corner. In Northern Hemisphere apples are in season from late summer to early winter. However, many varieties are available year round because they have been either kept in cold storage or imported from the Southern Hemisphere.
Apples are crisp, white-fleshed fruits with red, yellow or green skin. They range in taste from moderately sweet and refreshing to pleasantly tart depending on the variety. The apple is a member of the rose family, with a compartmentalized core that classifies it as a pome fruit.
This chart graphically details the %DV that a serving of Apples provides for each of the nutrients of which it is a good, very good, or excellent source according to our Food Rating System. Additional information about the amount of these nutrients provided by Apples can be found in the Food Rating System Chart. A link that takes you to the In-Depth Nutritional Profile for Apples, featuring information over 80 nutrients, can be found under the Food Rating System Chart.
- Health Benefits
- Description
- History
- How to Select and Store
- How to Enjoy
- Safety
- Nutritional Profile
- References
According to the latest research, the old saying, "An apple a day keeps the doctor away," is fact, not just folklore. The nutritional stars in apples-fiber, flavonoids, and fructose-translate into apples' ability to keep us healthy.
Cardio-Protective Fiber
Apples contain both insoluble and soluble fiber. One medium (5 ounces) unpeeled apple provides over 3 grams of fiber, more than 10% of the daily fiber intake recommended by experts. Even without its peel, a medium apple provides 2.7 grams of fiber.
Apple's two types of fiber pack a double punch that can knock down cholesterol levels, reducing your risk of hardening of the arteries, heart attack, and stroke.
Apple's insoluble fiber works like bran, latching on to LDL cholesterol in the digestive tract and removing it from the body, while apple's soluble fiber pectin reduces the amount of LDL cholesterol produced in the liver. Adding just one large apple (about 2/3 of a pound) to the daily diet has been shown to decrease serum cholesterol 8-11%. Eating 2 large apples a day has lowered cholesterol levels by up to 16%!
A study published in the Archives of Internal Medicine confirms that eating high fiber foods, such as apples, helps prevent heart disease. Almost 10,000 American adults participated in this study and were followed for 19 years. People eating the most fiber, 21 grams per day, had 12% less CHD and 11% less CVD compared to those eating the least, 5 grams daily. Those eating the most water-soluble dietary fiber fared even better with a 15% reduction in risk of CHD and a 10% risk reduction in CVD.
LDL cholesterol isn't the only harmful compound on apple's removal list. Pectin grabs toxins like the heavy metals lead and mercury, and ushers them out of the body. Both the soluble and insoluble fibers in apples have cancer-protective activity since they relieve constipation and send potentially toxic substances out with the stools.
When it comes to bowel regularity, apple's two types of fiber tackle the job-no matter what it is. Both the insoluble fiber in apples and their soluble fiber pectin help relieve constipation (thus helping to prevent diverticulosis and colon cancer). The insoluble fiber works like roughage, while the pectin, which is found primarily in the skin, acts as a stool softener by drawing water into the stool and increasing stool bulk. On the other hand, because pectin firms up an excessively loose stool, it's also used to treat diarrhea.
Cardio-Protective Flavonoids
A type of pigment in apples that helps provide their color, flavonoids have been extensively researched and found to help prevent heart disease. Researchers in Finland followed over 5,000 Finish men and women for over 20 years. Those who ate the most apples and other flavonoid-rich foods (such as onions and tea), were found to have a 20% lower risk of heart disease than those who ate the least of these foods.
Apples have been singled out as one of the small number of fruits and vegetables that contributed to the significant reduction in heart disease risk seen in a recent meta-analysis of seven prospective studies. Of the more than 100,000 individuals who participated in these studies, those who diets most frequently included apples, tea, onions, and broccoli-the richest sources of flavonoids-gained a 20% reduction in their risk of heart disease.
Apple skin and onions are the two major food sources of a potent flavonoid called quercitin. If, in addition to eating an apple a day, you add 2 tablespoons of onion and 4 cups of green tea (also rich in flavonoids) to your menu, you, like the men who consumed these foods in another study, may have a 32% lower risk of heart attack than people who consume less of these foods.
Quercitin's benefits derive from its antioxidant activity, especially when it teams up with another antioxidant, vitamin C, also found in apples, to bolster the body's immune defenses. This dynamic antioxidant duo provides another way (in addition to fiber) through which apples protect against cancer and also helps prevent the free radical damage to LDL cholesterol that promotes heart disease.
Juice Ranked among the Highest in Antioxidant Activity
Not all fruit juices are the same. They differ markedly in the variety of phenolic compounds and antioxidant activity, according to Alan Crozier, Professor of Plant Biochemistry and Human Nutrition, who, with colleagues at the University of Glasgow, evaluated 13 commercially available popular juices.
Concord grapes came out on top with the highest and broadest range of polyphenols and the highest overall antioxidant capacity. (The main components in purple grape juice were flavan-3-ols, anthocyanins, and hydroxycinnamates, together accounting for 93% of the total phenolic content.)
Other top scorers were cloudy apple juice, cranberry juice and grapefruit juice.
Other research (Oszmianski J, Wolniak M, et al., Journal of the Science of Food and Agriculture) has also found cloudy apple juice to be a healthier choice than clear since cloudy apple juices contain up to four times the amount of protective polyphenols as clear apple juices.
Results for the red grape juice were said to be equal to those for a Beaujolais red wine. Interestingly, however, white grape juice, mainly containing hydroxycinnamates, had the lowest total phenolic content.
The products analyzed were: Spray Classic Cranberry; Welch's Purple Grape; Tesco Pure Pressed Red Grape; Pomegreat Pomegranate; Tesco Pure Apple (clear); Copella Apple (cloudy); Tesco Pure Grapefruit; Tesco Value Pure Orange (concentrate); Tropicana Pure Premium Smooth Orange (squeezed); Tropicana Pure Premium Tropical Fruit; Tesco Pure Pressed White Grape; Tesco Pure Pineapple; Del Monte Premium Tomato.
Dr. Crozier's findings come shortly after those of the Kame project, which indicated that long-term fruit juice consumption can provide protection against Alzheimer's disease (Dai et al., Am J Med), and suggest that, since each fruit juice contains its own array of protective phenols, drinking a variety may offer the best protection. Practical Tip: "The message is to mix these juices during the week. That way you will get all the compounds with anti-oxidant activity. If you drink only one juice you risk missing out on the compounds in the others," explained Crozier.
Apples' Flavonoids Provide Much More than Antioxidant Protection
Apples have long been touted as an excellent source of flavonoids that act as antioxidants, moping up oxygen free radicals that can damage DNA. Now, Eric Gershwin and colleagues from the University of California, Davis, US, have discovered a new way in which flavonoid-rich apples help protect against heart disease and cancers that goes beyond their flavonoids' antioxidant effects.
The researchers prepared apple extracts from fresh Fuji, Golden Delicious, Red Delicious, and Granny Smith apples and added them to cultures of human endothelial cells (Endothelial cells make up the inner lining of our arteries. Their damage by oxidized cholesterol is one of the first steps in the development of atherosclerosis.)
After incubating the endothelial cells with apple extract, the researchers exposed them to tumor necrosis factor (TNF), a compound that triggers cell death and promotes inflammation by inducing a chemical signaling pathway called the nuclear factor (NF) kappa B pathway. The apple flavonoids were able protect the cells from the effects of TNF by inhibiting the signals in this pathway that would otherwise damage or kill cells. Gershwin and colleagues' research, published in Experimental Biology and Medicine, shows that apple flavonoids protect cells from damage and death by interfering with communications between cells-a further mechanism than their antioxidant effects.
Fructose for Stable Blood Sugar Levels
Apples derive almost all of their natural sweetness from fructose, a simple sugar, but one which is broken down slowly, especially when combined with apples' hefty dose of fiber, thus helping to keep blood sugar levels stable.
Prevent Kidney Stones
Want to reduce your risk of calcium oxalate kidney stones? Drink apple juice. A study published in the British Journal of Nutrition found that when women drank ½ to 1 liter of apple, grapefruit or orange juice daily, their urinary pH value and citric acid excretion increased, significantly dropping their risk of forming calcium oxalate stones.
Promote Optimal Health
Whole apple extracts-in amounts comparable to human consumption of one, three or six apples a day-were shown to prevent breast cancer in test animals in a study published in the Journal of Agricultural and Food Chemistry.
And apples worked in a dose-dependent manner; the more apples eaten, the more protection.
In a second study, published in Molecular Nutrition and Food Research, a polyphenol-rich extract of an apple juice blend powerfully inhibited the growth of human colon cancer cells in the laboratory.
However, when researchers put together a mixture containing only the bioactive compounds identified in apple juice so far (which included its proanthocyanidins and quercetin), the mixture was ineffective in inhibiting the growth of colon cancer cells.
They concluded that as yet unknown constituents contribute to apples' potent protective qualities. The conclusion we draw at the World's Healthiest Foods is that it is not single nutrients, but their synergy in whole, natural foods that is the source of their effectiveness in promoting health.
We definitely agree with the researchers in the first (breast cancer) study, who suggest that because apples are so richly endowed with phytonutrients capable of strong antioxidant and anticancer activities and are so universally enjoyed, eating an apple (or two) a day may be effective (and we'd add easy and inexpensive) way to lessen the incidence of breast (and colon) cancer.
Natural Sun Protection
It's long been known that apple peel contains high concentrations of special antioxidant compounds called phenols that may assist in the prevention of a number of chronic diseases. Now it appears that the phenols in the skin of certain cultivars of apples may provide a hefty dose of UV-B protection, according to a study published in the Journal of Experimental Botany. Researchers evaluated both Granny Smith and Braeburn apples, with Braeburns being the clear winner in terms of their ability to accumulate UV-B protective quercitin glycosides in their sun-exposed skin. Sun-kissed Braeburns were resistant to high doses of UV-B radiation (up to 97kJ m-2). Next time you plan to spend time in the sun yourself, start your day with a Braeburn apple or bring one or two along for lunch and snacks.
Review Study Provides Even More Reasons to Enjoy Apples
A major review study published in the Nutrition Journal provides dozens of reasons to enjoy an apple every day.
A review study is one that looks at the results of many other studies. This one included an analysis of 85 studies. Apples were found to be most consistently associated with a reduced risk of cancer, heart disease, asthma, and type 2 diabetes when compared to other fruits and vegetables. In addition, eating apples was also associated with increased lung function and increased weight loss.
Here are some of the reasons why:
Apples are a rich and very important source of phytonutrients, including flavonoids and phenols, in the American diet and in Europe. In the United States, 22% of the phenolic compounds consumed from fruits come from apples, making them the largest source of phenols in the American diet.
When compared to other fruits, apples ranked second in total concentration of phenolic compounds, and perhaps more importantly, had the highest portion of free phenols. Since free phenols are not bound to other compounds in the fruit, they may be more available for absorption into the bloodstream.
Apples are also an excellent source of antioxidants, and when compared to many other commonly consumed fruits in the United States, were found to have the second highest level of antioxidant activity. Many of the phytonutrients found in apples, including quercetin, catechin, phloridzin and chlorogenic acid, are strong antioxidants.
The total antioxidant activity of 100 grams of whole apple (with the peel) was found to be equivalent to the antioxidant effect of about 1500 mg of vitamin C. (However, the amount of vitamin C in 100 g of apples is only about 5.7 mg. Nearly all of the antioxidant activity from apples comes from a variety of other compounds.)
Whole apples, especially their peels, have been found to have a number of powerful antioxidant effects, one of which is to protect VLDL and LDL ("bad") cholesterol from oxidation. Yet when quercitin, one of the most important antioxidant flavonoids in apples, was tested by itself in laboratory animals, it had no protective effect. And when apple flesh and apple juice were tested, they provided less than a tenth the benefit of whole apple.
Apples' protective effects against free radical damage to cholesterol reach their peak at three hours following apple consumption and drop off after 24 hours, providing yet another good reason to eat a whole fresh apple a day.
In animal studies, apples have also been shown to lower LDL ("bad") cholesterol while raising beneficial HDL cholesterol. Not only did the laboratory animals in these studies produce less cholesterol, but they also excreted more in their feces when fed apples, pears and peaches-but apples had the greatest cholesterol-lowering effect.
In the most recent studies, investigators found that the combination of apple pectin and apple phenols lowered cholesterol and triglycerides to a much greater extent than either apple pectin or phenols alone. This again suggests a beneficial synergy between the many healthful compounds found in apples and supports eating the whole fruit instead of simply drinking apple juice, eating peel-free applesauce or taking fiber supplements.
Apples have also been shown to greatly inhibit the growth of liver and colon cancer cells in several studies. In one study, at a dose of 50 mg/mL, liver cancer cell proliferation was inhibited by 39% by extracts of whole Fuji apple and 57% by whole Red Delicious extracts. In another study in which colon cancer cells were treated with apple extracts, cell proliferation was inhibited 43% at a dose of 50 mg/mL.
Promote Optimal Health
Eating an apple a day may also offer significant protection against breast cancer, suggests an animal study published in the Journal of Agricultural and Food Chemistry . When laboratory animals with breast cancer were fed the human equivalent of 1, 3 or 6 apples a day for 6 months, their tumors shrank by 25%, 25%, and 61%, respectively.
Researchers credit apples' strong protective action to the synergistic interactions among the wide variety of potent antioxidant and antiproliferative phytonutrients, including phenolics and flavonoids, they contain.
In several large epidemiological (population) studies conducted in the United Kingdom, Finland and the Netherlands, apple consumption (a minimum of 2 apples per week) was found to be inversely linked with asthma and type 2 diabetes, and positively associated with general lung health. Researchers attribute apples' protective effects in these conditions to apples' high concentration of anti-inflammatory flavonoids, such as quercitin and catechin.
In addition to their beneficial effects against chronic diseases including cancer, cardiovascular disease, asthma and diabetes, apples may also help combat cholera. Recently, crude extracts from immature apples were found to inhibit cholera toxin in a dose dependent manner by up to 98%.
Variation in Antioxidant Phytonutrients Among Different Types of Apples
Researchers have found distinct differences in total phenolic and flavonoid content among different apple varieties:
Of the four common varieties used for applesauce (Rome Beauty, Idared, Cortland, and Golden Delicious), Rome Beauty had the highest phenolic content.
Out of 10 varieties commonly consumed in the U.S., Fuji apples had the highest total phenolic and total flavonoid compounds, but Red Delicious apples were also quite high. These apple varieties also tended to have higher antioxidant activity.
Apple phytonutrient content is not greatly affected by storage. After 100 days, the amount of phenolic compounds in the skin begins to decrease slightly, but even after 200 hundred days in cold storage, the total amount of these compounds remains close to the level at the time of harvest.
However, processing apples into juice greatly lowers their phytonutrient content. Apple juice obtained from Jonagold apples by pulping and straight pressing had only 10% of the antioxidant activity of fresh apples, while juice obtained after pulp enzyming had only 3% of fresh apples' antioxidant activity.
The take home message: store apples in the refrigerator and enjoy a sweet, crunchy, whole apple at least 2-3 times each week.
A Flavonoid Unique to Apples May Help Prevent Menopausal Bone Loss
A flavonoid found only in apples called phloridzin may help prevent bone loss associated with menopause, suggests a study published in Calcified Tissue International..
A side effect of the sex hormone changes that occur during a woman's transition through menopause is a tendency towards increased inflammation and free radical production, which in turn, promotes bone loss.
Because of their anti-inflammatory actions, polyphenols have been suggested as one means of protecting against bone loss during this pro-inflammatory time in women's lives.
To test this theory, French researchers ovariectomized lab animals (to simulate menopause) and divided them into two groups, which were given either a control diet or a diet supplemented with phloridzin for 80 days. Three weeks before the animals were sacrificed, 10 animals in each group were put into an inflammatory state.
While all the animals on the control diet lost bone, and those in the inflammatory state lost even more bone, the rats receiving phloridzin not only did not lose bone, but actually increased bone mineral density-even if they were experiencing a high inflammatory state!
If you're moving through menopause, eating an apple a day may help you keep bone loss at bay.
Apples are a crisp, white-fleshed fruit with a red, yellow or green skin. The apple is actually a member of the rose family, which may seem strange until we remember that roses make rose hips, which are fruits similar to the apple.
Apples have a moderately sweet, refreshing flavor and a tartness that is present to greater or lesser degree depending on the variety. For example, Golden and Red Delicious apples are mild and sweet, while Pippins and Granny Smith apples are notably brisk and tart. Tart apples, which best retain their texture during cooking, are often preferred for cooked desserts like apple pie, while Delicious apples and other sweeter varieties like Braeburn and Fuji apples are usually eaten raw.
The apple tree, which originally came from Eastern Europe and southwestern Asia, has spread to most temperate regions of the world. Over the centuries, many hybrids and cultivars have been developed, giving us the 7,000 varieties in the market today.
Apples have long been associated with the biblical story of Adam and Eve, although there is actually no mention that, in fact, the fruit in question was actually an apple. In Norse mythology, apples were given a more positive persona: a magic apple was said to keep people young forever. Apples' most recent appearance in history occurred in the 1800s in the U.S., when Johnny Appleseed-a real person named John Chapman, despite the mythological quality of his tale-walked barefoot across an area of 100,000 square miles, planting apple trees that provided food and a livelihood for generations of settlers.
Look for firm fruits with rich coloring. Yellow and green apples with a slight blush are best. Your preference for a sweeter or more tart fruit and whether you plan to enjoy your apples raw or cooked will guide your choice of variety. Just remember that Red and Golden Delicious are among the sweetest apples. Braeburn and Fuji apples are slightly tart, and Gravenstein, Pippin and Granny Smith apples are the most tart, but retain their texture best during cooking.
In the northern hemisphere, apple season begins at the end of summer and lasts until early winter. Apples available at other times have been in cold storage or are imported from the southern hemisphere.
Whole apples are a much better nutritional choice than apple juice. Not only are whole apples richer in dietary fiber, but the current processes of juicing seem to drastically reduce the polyphenolic phytonutrient concentrations originally found in the whole fruit.
When selecting apple juice, chose cloudy rather than clear juices:
Researchers evaluated the polyphenolic content of clear and cloudy apple juices from Idared and Champion varieties. Cloudy juices, particularly those prepared from apples of the Champion variety, had a much higher content of procyanidins (a type of flavonoid) than clear juices.
Cloudy juice from Champion apples contained 1,044 milligrams of polyphenols per liter, while clear juice made from Idared apples contained only 250 milligrams per liter. When the juices' ability to neutralize free radicals was evaluated, cloudy Champion apple juice neutralized 93% of the radicals after 3 minutes, compared to only 24% for the clear Idared juice.
In addition to being eaten raw, apples are a wonderful addition to a variety of recipes from salads to baked goods. For some of our favorite recipes, click Recipes.
Tips for preparing apples:
Rinse apples under clear running water like you would any fruit. If organic, don't peel unless the recipe you have chosen requires peeled apples.
To prevent browning when slicing apples for a recipe, simply put the slices in a bowl of cold water to which a spoonful of lemon juice has been added.
For use in future recipes, sliced apples freeze well in plastic bags or containers.
A few quick serving ideas:
Add diced apples to fruit or green salads.
Braise a chopped apple with red cabbage.
Looking for an alternative to sweet desserts? Sliced apples (either alone or with other fruits) and cheese are a European favorite.
Try our wonderful Apple Tart in the recipe file.
Apples and Pesticide Residues
Virtually all municipal drinking water in the United States contains pesticide residues, and with the exception of organic foods, so do the majority of foods in the U.S. food supply. Even though pesticides are present in food at very small trace levels, their negative impact on health is well documented. The liver's ability to process other toxins, the cells' ability to produce energy, and the nerves' ability to send messages can all be compromised by pesticide exposure. According to the Environmental Working Group's 2006 report "Shopper's Guide to Pesticides in Produce," apples are among the 12 foods on which pesticide residues have been most frequently found. Therefore, individuals wanting to avoid pesticide-associated health risks may want to avoid consumption of apples unless they are grown organically.
If you do purchase non-organic apples, you may want to ask your grocer about the kind of wax used to protect the apple's surface during storage or shipping. Carnauba wax (from the carnauba palm tree), beeswax, and shellac (from the lac beetle) are preferable to petroleum-based waxes, which contain solvent residues or wood resins.
Apples are a good source of dietary fiber and vitamin C.
Most of the apple's fiber is contained in its skin, as is the majority of its quercitin. Unfortunately, in conventionally grown apples, the apple skin is also the part most likely to contain pesticide residues and may have toxic residues if covered in petroleum-based waxes. Since peeling results in the loss of apples' flavonoids and most of its valuable fiber, choose organically grown apples whenever possible.
For an in-depth nutritional profile click here: Apples.
In-Depth Nutritional Profile
In addition to the nutrients highlighted in our ratings chart, an in-depth nutritional profile for Apples is also available. This profile includes information on a full array of nutrients, including carbohydrates, sugar, soluble and insoluble fiber, sodium, vitamins, minerals, fatty acids, amino acids and more.Introduction to Food Rating System Chart
The following chart shows the nutrients for which this food is either an excellent, very good or good source. Next to the nutrient name you will find the following information: the amount of the nutrient that is included in the noted serving of this food; the %Daily Value (DV) that that amount represents; the nutrient density rating; and the food's World's Healthiest Foods Rating. Underneath the chart is a table that summarizes how the ratings were devised. Read detailed information on our Food and Recipe Rating System.
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