Apples are so familiar to consumers that they are often not given their due in terms of the outstanding nourishment that they provide. And no apple nutrients stand out more prominently than its phenolic phytonutrients. We're talking about literally dozens of phenols and polyphenols that combine to give apples their renowned antioxidant capacity. To give you a better idea of just how extensive these apple phytonutrients are, we created the list below.
The phytonutrients listed above can be found in the skins (peels) of apples as well as their flesh (pulp). Many of these phytonutrients are 3–4 times more concentrated in the skin. However, since the physical amount of flesh in an average apple is much greater than the amount of skin, you can still get important phytonutrient benefits from the flesh. When you combine the availability of phenolic nutrients by consuming both peel and pulp, you can take advantage of nearly 90% of the total antioxidant capacity provided by apples. In terms of quantity, you can expect to get between 66–212 milligrams of total phenolic phytonutrients from about 1/2 (100 grams) of a medium fresh apple.
It is not surprising to see a combination of both animal and human studies showing cardiovascular benefits from consumption of this popular fruit. Most of the phenolic phytonutrients listed earlier in this section have been shown to function as antioxidants in the body and to provide antioxidant protection within blood vessels. In one recent study, consumption of one apple per day over a period of 4 weeks resulted in significantly decreased blood levels of oxidized LDL cholesterol. Additionally, this decrease in oxidized LDL was associated with a lowered risk of atherosclerosis.
Multiple animal studies on apple extracts have further linked apple consumption to decreased levels of LDL cholesterol overall (versus levels of oxidized LDL only). The mechanisms of action here are not entirely clear, but most researchers point to the ability of fiber-related components in apple to bind together with bile acids. When bound together with fiber-like components, bile acids can be more readily excreted from the body. Following their excretion, our cells will break apart some existing cholesterol into its bile acid components as a way to replace the bound bile acids that were excreted.
Total cholesterol and triglyceride levels in the blood have been shown to decrease in animal studies involving intake of apple extracts. Researchers have hypothesized a role not only for fiber-related apple components in this process, but for apple phytonutrients as well.
Also of interest in recent studies has been the potential role of gut bacteria in enhancing the cardiovascular support provided to us by apples. For example, studies show that certain forms of bile acids (called deconjugated bile acids) can act as signaling molecules which are able to bind onto cell nucleus receptors called farnesoid X receptors (FXRs) and inhibit synthesis of fat. These special forms of bile acids can be created by gut bacteria, provided that they have the right bile acids to work with. By binding together with bile acids higher up in the digestive tract, apple components may be able to help deliver these bile acids to the gut bacteria.
In our WHFoods rating system, apples rank as a good source of dietary fiber and provide about 4.4 grams of fiber per medium-sized apple. Pectin is the primary soluble fiber in apples, and it is a fiber with well-studied benefits for our digestive tract. Pectin is a soluble fiber that can help slow the pace of stomach emptying (also called gastric emptying) as well as the speed through which foods move along through the digestive tract (called transit time). As a consequence, the body is better able to stabilize blood sugar metabolism. Not only has apple pectin been studied in this regard, but its component parts—homogalacturonans and rhamnogalacturonans—have been studied as well. This relationship explains one of the key ways in which apple intake can help improve regulation of blood sugar.
Phloretin—one of the phenolic dihydrochalcones in apple—may also have an important role to play in the blood sugar-related benefits of apple consumption. In animal studies, phloretin obtain from apples has been shown to help stabilize blood glucose levels, plasma insulin levels, and lessen insulin resistance as measured by the homeostasis model assessment of insulin resistance (HOMA-IR). Eventually, we expect studies on humans enjoying apples in their weekly meal plan to show some of these same blood sugar-related benefits.
The potential role for apple intake in prevention of colon cancer is another area of strong research interest. Most of the studies to date have involved use of apple extracts in colon cancer cell lines in the laboratory or on rats or mice with experimentally induced cancers. Importantly, researchers already know that many different apple components can make their way through the human digestive tract and arrive at the very end region of our large intestine—namely, the colon. So this knowledge helps set the stage for future research in this key area.
In terms of their diversity, apples aren't likely to take a back seat to any other fruit. As mind-boggling as it might seem, thousands of varieties of apples are produced and enjoyed worldwide. Even within U.S. supermarkets, it is not unusual to see more than a dozen varieties available for purchase in a single produce section. Apple varieties can differ widely in texture, aroma, color, and taste. Apple lovers often talk about "crunchy" versus "crisp" or "bold" versus "hints" of tartness. You can find apples with skins that range in color from pale to vibrant shades of yellow, green, and red, as well as those that are gold, pink, scarlet or extremely dark crimson/purple. Apple flesh can also vary widely in color, from virtually white to diverse shades of most colors listed above. Apple skins may also feature a mixture of colors (and may be referred to as bicolor, tricolor, etc.). The chart below will give you a quick look at some popular apple varieties in the United States.
|Name||Flavor/Texture||Place of Origin||Year Introduced into the Marketplace|
|Granny Smith||crunchy and tart||Australia||1868|
|Red Delicious||crunchy and mildy sweet||Iowa, U.S.A.||1874|
|Golden Delicious||crunchy and sweet||West Virginia, U.S.A.||1914|
|Golden Delicious||crisp and sweet||West Virginia, U.S.A.||1914|
|Fuji||crunchy and sweet||Japan||1962|
|Gala||crisp and aromatically sweet||New Zealand||1965|
|Honeycrisp||crisp and sweet||Minnesota, U.S.A.||1991|
Given the unusual diversity of varieties for this fruit, we also wanted to provide you with a more comprehensive alphabetical list of apple types that you may hear about or come across in the grocery. These include: Akane, Almata, Ambrosia, Arkansas Black, Aurora, Autumn Glory, Black Twig, Braeburn, Cameo, Cortland, Crispen, Criterion, Early Gold, Elstar, Empire, Enterprise, Fuji, Gala, Ginger Gold, Gold Russet, Golden Delicious, Granny Smith, Gravenstein, Hunt Russet, Ida Red, Jersey Mac, Jonagold, Jonalicious, Jonamac, Jonathan, Kanzi, Keepsake, Lady Alice, Lodi, Macoun, McIntosh, Melrose, Mutsu, Newton, Northern Spy, Pacific Rose, Paula Red, Pink Lady, Pippin, Red Cort, Red Delicious, Rome, Sonya, Spartan, Sundance, Sunrise, Sweet Tango, Winesap, and Yates.
Apple tree orchards can be as diverse as their fruit. Standard apple trees often reach approximately 30 feet in height and 30 feet in diameter (at the crown), and their size limits the number that can be planted in one acre. In addition, they take a number of years to reach full size. It is common to imagine this type of orchard when thinking about apples—a relatively spacious landscape with a relatively small number of trees that stand out individually. However, apple growers can also select from a variety of tree (or "rootstock") types including semi-dwarf trees that stop at 14–22 feet in height, or dwarf trees that stop at 6–12 feet or less. Due to their smaller size, these apple trees can be planted more closely together, allowing for 150–750 trees per acre. In addition, they are typically provided with a training or trellising system to support growth. These different orchard options can allow growers to take advantage of relationships between apple varieties, landscape conditions, and angles of sunlight. The net result is an amazing diversity of apples that we enjoy.
You may find a bit of discrepancy in the scientific naming of apples. Without question, all apples belong to the Rosaceae family of plants. This broad family includes a large number of plants with edible fruits, including not only apples but also apricots, cherries, loquats, peaches, plums, raspberries, and strawberries. As the name implies, roses are also a key member of this plant family, as are their seed pods—namely, rose hips.
Also without question is the genus to which apples belong. This genus is called Malus. However, once you arrive at the species name for apples, you will find some inconsistencies. The most common genus/species name that you will find for this fruit is Malus domestica. However, you may also find the following variations in naming: Malus pumila, Malus sylvestris, Malus communis, Malus praecox, and Malus pumila var. domestica. For the most part, these different science names point back to the role played over time by different authorities in the field of taxonomy in their efforts to create an accurate naming system.
One final note about apples and their variety: also found in this Malus genus are the close relatives of apples—namely, crabapples. Crabapple trees produce smaller fruit than their fellow apple trees—usually less than two inches in diameter. They are sometimes grown primarily for ornamental reasons, even though most of their fruits are edible. While more often used in sauces, jellies, and preserves, some varieties of crabapple (like Chestnut Crabapple) are popular as fresh fruits.
The history of this much-loved fruit has some unique aspects. Current genetic evidence points to a wild species of apple (Malus sieversii) in the Tian Shan Mountains of Central Asia as the key ancestor for present-day apples. However, this wild species was quickly domesticated and then carried along the Silk Trade routes to parts of the Caucasus Mountains in Western Asia and also into Europe, where natural crosses took place with other wild apple species. As a result, the early development of apples involved a wide range of habitats and many different species. This early diversity helped pave the way for the thousands of apple varieties that exist today.
On a worldwide basis, China is currently ranked as the top apple-producing country. It is followed (in order) by the United States, Turkey, Poland, Italy, India, France, Chile, Iran, and the Russian Federation.
Within the U.S., more than 30 different states grow apples for commercial sale. In terms of total production volume, the top-ranked states are Washington, New York, Michigan, Pennsylvania, and California. This large-scale domestic production also leads to the export of approximately 25% of all U.S. apples. The top 10 varieties of apples produced within the U.S. include Empire, Fuji, Gala, Golden Delicious, Honeycrisp, Granny Smith, McIntosh, Red Delicious, Rome, and Pink Lady.
Due to the popularity of apples as the second most widely-consumed whole fruit in the U.S. (following bananas), many groceries seek to stock a full range of apple varieties year-round. To boost year-round availability of this fruit, about 5% of apples consumed in the U.S. each year are imported from other countries, including Chile, Canada, and New Zealand.
Look for firm fruits with rich coloring, but expect the exact shading to differ depending on the specific variety involved. Depending on the taste and texture that you are seeking, there is no reason to limit yourself to apples of any particular color. Yellows, greens, reds, pinks, scarlets, bicolor, and tricolor—all of these types can make excellent choices. If you are seeking mostly sweetness, Red Delicious and Golden Delicious can make great choices. At the tart end of the taste spectrum, consider choosing a Granny Smith. For fascinating mixtures of sweet and tart, good choices would include Fuji, Braeburn, Gravenstein, Jonagold, and Jonathan. Many apple varieties— including Braeburn, Cortland, Honeycrisp, Gala, Granny Smith, Jonathan, Jonagold, Melrose, Mutsu, Pink Lady, and Winesap— retain their texture well during cooking. In the Northern Hemisphere, apple season begins toward the end of summer and lasts until early winter. Apples available at other times have either been in cold storage or have been imported from the Southern Hemisphere.
Within the U.S., between 25–30 pounds of apples per person are consumed each year if you include all forms of apple (e.g., apple sauce, apple juice, etc.). In fact, only one-third of total apple consumption comes from fresh whole apples. For this reason, we want to address the issue of quality in these other apple forms. To start with a general conclusion: the quality of apple sauces and apple juices can vary greatly! At one end of the spectrum you can find apple juices that have been ultrafiltered to remove the pulp and clarified to provide a clear juice with little-to-no fiber and a much depleted offering of polyphenols. At the other end of the spectrum, you can find apple juices that have been processed but later recombined with some percentage of the previously extracted pulp. This recombination of juice with pulp usually results in a cloudy appearance, and the pulpy portion can also sometimes be seen as having settled to the bottom of the bottle. Without question, you are likely to get more health benefits from apple juice if you select juices that contain sizeable amounts of pulp. However, even though these pulp-rich juices can provide you with greater nutrient benefits than filtered and/or clarified versions, they can still fall short in some critical nutrient areas due to the impact of processing. For example, polyphenols in apples can be exposed to oxidative conditions during pulping, pressing, and clarification. As a result, the polyphenol benefits from whole, fresh apples can be reduced during the processing of apple juice, even when pulp is included in the final product. This potential nutrient loss is one of the reasons that we favor consumption of whole (and whole-sliced) apples in a minimally processed form.
Because we often get asked about the use of wax on apples, we wanted to address this topic for you here in the selection section.
The use of "edible coatings" on fruits and vegetables has become a relatively high-tech segment of the food industry. When fresh fruits and vegetables require modified atmosphere storage (involving control of factors like temperature, humidity, and oxygen concentration), this step in the food supply chain can become both complicated and expensive. To a certain extent, edible coatings on fruits and vegetables can accomplish some of the same goals that are provided by modified atmosphere storage, thus increasing shelf life at a lesser cost. In addition, coatings can provide a level of physical protection during handling.
A number of different coatings are approved for use on apples. These coatings can come from many different sources including lab polymers, petroleum products, trees, plant leaves, and insects. Use of fruit waxes has always been controversial. Many people who strive to avoid waxed fruit regard waxes as a type of food additive that is separate and apart from fruit in its natural form. In this context, it's worth noting that many fruits—including apples—can synthesize their own wax-like coating (called the "cuticle"). So it is possible for the waxy sheen of an apple to be a natural part of this fruit's development.
Strict limits on the use of added fruit waxes are provided in the organic regulations set forth by the U.S. Department of Agriculture (USDA) in its National Organics Program. For certified organic fruits, allowed coatings include carnauba wax (obtained from the leaves of the carnauba palm tree) and wood resin (typically produced from the oleoresins found in pine trees). The allowed use of these waxes on organic fruit (including organic apples) remains controversial, however. Despite their classification as "nonsynthetic" due to their natural sources, these waxes undergo considerable processing prior to their spray application and are different from the wax-like substances naturally produced by many apple varieties.
Fortunately, if waxed apples are a version of this fruit that you choose to avoid, you are likely to find some unwaxed versions in the produce department. However, you may have to ask the produce manager for help in selecting unwaxed apples, since it can sometimes be impossible to tell based solely on their appearance.
At WHFoods, we encourage the purchase of certified organically grown foods, and apples are no exception. Repeated research studies on organic foods as a group show that your likelihood of exposure to contaminants such as pesticides and heavy metals can be greatly reduced through the purchased of certified organic foods, including apples. In many cases, you may be able to find a local organic grower who sells watermelon but has not applied for formal organic certification either through the U.S. Department of Agriculture (USDA) or through a state agency. (Examples of states offering state-certified organic foods include California, New York, Oregon, Vermont, and Washington.) However, if you are shopping in a large supermarket, your most reliable source of organically grown apples is very likely to be apples that display the USDA organic logo.
In general, apples are fairly resilient to home storage at typical refrigerator temperatures of 35°–40°F (2°–4°C). At these temperatures, you can expect your apples to stay in good shape for at least several weeks. It can be very helpful to maintain some moisture in the cold storage area, for example, by inclusion of damp cheesecloth in the crisper bin of a refrigerator. Some varieties of apples—for example, Granny Smith—will store well for considerably longer. However, when most apple varieties are successfully stored over a 3-4 month period of time, the storage temperatures are usually lower than 35°–40°F (2°–4C) and fall into the range of 30°–32°F (-1°–0–C). These longer storage periods are also typically accompanied by a high percent of relative humidity in the range of 90–95%.
Over a period of time involving months, there is loss of total polyphenols from apples, including both flavonoid and non-flavonoid polyphenols. However, valuable amounts of polyphenols (and all other nutrients) remain. In some food traditions, cold storage of apples over the winter months is still counted on as a key part of dietary nourishment from fruits.
You've no doubt heard the saying, "one bad apple can spoil the whole bunch." Well, research studies agree. An apple that has been bruised from being dropped (or that has been damaged in some other way) can start to release higher than usual amounts of ethylene gas. This ethylene gas then acts as a hormone that speeds up the ripening of nearby apples that have not been damaged. As a result, the entire group of apples can too quickly become overly ripe. To avoid this problem, we recommend that you handle apples with care and remove any damaged apples from the group if you are storing multiple apples together.
If you'd like even more recipes and ways to prepare apples the Nutrient-Rich Way, you may want to explore The World's Healthiest Foods book.
|vitamin C||8.37 mg||11||2.1||good|
Density>=7.6 AND DRI/DV>=10%
Density>=3.4 AND DRI/DV>=5%
Density>=1.5 AND DRI/DV>=2.5%