Eggplant

An Important Message About Eggplant

We have placed nightshade vegetables (such as eggplant) on our "10 Most Controversial WHFoods List." This list was created to let you know that even though some foods (like eggplant) can make an outstanding contribution to your meal plan, they are definitely not for everyone. Nightshade vegetables can be difficult to find in high-quality form; can be more commonly associated with adverse reactions than other foods; and can present more challenges to our food supply in terms of sustainability. More details about our 10 Most Controversial WHFoods can be found here.

About Eggplant

Long prized for its deeply purple, glossy beauty as well as its unique taste and texture, eggplants are now available in markets throughout the year, but they are at their very best from August through October when they are in season.

Eggplants belong to the nightshade family of vegetables, which also includes tomatoes, sweet peppers and potatoes. They grow in a manner much like tomatoes, hanging from the vines of a plant that grows several feet in height. While the different varieties do range slightly in taste and texture, one can generally describe the eggplant as having a pleasantly bitter taste and spongy texture. 

Eggplant, cubed, cooked
1.00 cup
(99.00 grams)

Calories: 35
GI: low

NutrientDRI/DV

 fiber9.8%

 vitamin B16.6%

 copper6.6%

 manganese5.5%

 vitamin B65.2%

 vitamin B33.6%

 potassium3.4%

 folate3.4%

 vitamin K3.1%

This chart graphically details the %DV that a serving of Eggplant 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 Eggplant can be found in the Food Rating System Chart. A link that takes you to the In-Depth Nutritional Profile for Eggplant, featuring information over 80 nutrients, can be found under the Food Rating System Chart.

• Health Benefits
• Description
• History
• How to Select and Store
• Tips for Preparing and Cooking
• How to Enjoy
• Individual Concerns
• Nutritional Profile
• References

Health Benefits

In addition to featuring a host of vitamins and minerals, eggplant also contains important phytonutrients, many which have antioxidant activity. Phytonutrients contained in eggplant include phenolic compounds, such caffeic and chlorogenic acid, and flavonoids, such as nasunin.

Brain Food

Research on eggplant has focused on an anthocyanin phytonutrient found in eggplant skin called nasunin. Nasunin is a potent antioxidant and free radical scavenger that has been shown to protect cell membranes from damage. In animal studies, nasunin has been found to protect the lipids (fats) in brain cell membranes. Cell membranes are almost entirely composed of lipids and are responsible for protecting the cell from free radicals, letting nutrients in and wastes out, and receiving instructions from messenger molecules that tell the cell which activities it should perform.

Rich in Phenolic Antioxidant Compounds

Researchers at the US Agricultural Service in Beltsville, Maryland, have found that eggplants are rich sources of phenolic compounds that function as antioxidants. Plants form such compounds to protect themselves against oxidative stress from exposure to the elements, as well as from infection by bacteria and fungi.
The good news concerning eggplant is that the predominant phenolic compound found in all varieties tested is chlorogenic acid, which is one of the most potent free radical scavengers found in plant tissues. Benefits attributed to chlorogenic acid include antimutagenic (anti-cancer), antimicrobial, anti-LDL (bad cholesterol) and antiviral activities.
ARS researchers studied seven eggplant cultivars grown commercially in the U.S. and a diverse collection of exotic and wild eggplants from other counties. In addition to chlorogenic acid, they found 13 other phenolic acids present at significantly varying levels in the commercial cultivars, although chlorogenic acid was the predominant phenolic compound in all of them. Black Magic—a commercial eggplant cultivar representative of U.S. market types—was found to have nearly three times the amount of antioxidant phenolics as the other eggplant cultivars that were studied. In addition to their nutritive potential, the phenolic acids in eggplant are responsible for some eggplants' bitter taste and the browing that results when their flesh is cut. An enzyme called polyphenol oxidase triggers a phenolic reaction that produces brown pigments. Scientists have begun work on developing eggplant cultivars with an optimal balance of phenolics to ensure both optimal nutritional value and pleasing taste.

Cardiovascular Health and Free Radical Protection

When laboratory animals with high cholesterol were given eggplant juice, their blood cholesterol, the cholesterol in their artery walls and the cholesterol in their aortas (the aorta is the artery that returns blood from the heart back into circulation into the body) was significantly reduced, while the walls of their blood vessels relaxed, improving blood flow. These positive effects were likely due not only to nasunin but also to several other terpene phytonutrients in eggplant.

Nasunin is not only a potent free-radical scavenger, but is also an iron chelator. Although iron is an essential nutrient and is necessary for oxygen transport, normal immune function and collagen synthesis, too much iron is not a good thing. Excess iron increases free radical production and is associated with an increased risk of heart disease and cancer. Menstruating women, who lose iron every month in their menstrual flow, are unlikely to be at risk, but in postmenopausal women and men, iron, which is not easily excreted, can accumulate. By chelating iron, nasunin lessens free radical formation with numerous beneficial results, including protecting blood cholesterol (which is also a type of lipid or fat) from peroxidation; preventing cellular damage that can promote cancer; and lessening free radical damage in joints, which is a primary factor in rheumatoid arthritis.

Description

Eggplant, or aubergine as it is called in France, is a vegetable long prized for its beauty as well as its unique taste and texture. Eggplants belong to the plant family ofSolanaceae, also commonly known as nightshades, and are kin to the tomato, bell pepper and potato. Eggplants grow in a manner much like tomatoes, hanging from the vines of a plant that grows several feet in height.

One of the most popular varieties of eggplant in North America looks like a pear-shaped egg, a characteristic from which its name is derived. The skin is glossy and deep purple in color, while the flesh is cream colored and spongy in consistency. Contained within the flesh are seeds arranged in a conical pattern.

In addition to this variety, eggplant is also available in a cornucopia of other colors including lavender, jade green, orange, and yellow-white, as well as in sizes and shapes that range from that of a small tomato to a large zucchini.

While the different varieties do vary slightly in taste and texture, one can generally describe the eggplant as having a pleasantly bitter taste and spongy texture. In many recipes, eggplant fulfills the role of being a complementary ingredient that balances the surrounding flavors of the other more pronounced ingredients.

History

The ancient ancestors of eggplant grew wild in India and were first cultivated in China in the 5th century B.C. Eggplant was introduced to Africa before the Middle Ages and then into Italy, the country with which it has long been associated, in the 14th century. It subsequently spread throughout Europe and the Middle East and, centuries later, was brought to the Western Hemisphere by European explorers. Today, Italy, Turkey, Egypt, China and Japan are the leading growers of eggplant.

Although it has a long and rich history, eggplant did not always hold the revered place in food culture that it does today, especially in European cuisines. As a result of the overly bitter taste of the early varieties, it seems that people also felt that it had a bitter disposition—eggplant held the undeserved and inauspicious reputation of being able to cause insanity, leprosy and cancer.

For centuries after its introduction into Europe, eggplant was used more as a decorative garden plant than as a food. Not until new varieties were developed in the 18th century, did eggplant lose its bitter taste and bitter reputation, and take its now esteemed place in the cuisines of many European countries, including Italy, Greece, Turkey and France.

How to Select and Store

Choose eggplants that are firm and heavy for their size. Their skin should be smooth and shiny, and their color, whether it be purple, white or green, should be vivid. They should be free of discoloration, scars, and bruises, which usually indicate that the flesh beneath has become damaged and possibly decayed.

The stem and cap, on either end of the eggplant, should be bright green in color. As you would with other fruits and vegetables, avoid purchasing eggplant that has been waxed. To test for the ripeness of an eggplant, gently press the skin with the pad of your thumb. If it springs back, the eggplant is ripe, while if an indentation remains, it is not.

Although they look hardy, eggplants are actually very perishable and care should be taken in their storage. Eggplants are sensitive to both heat and cold and should ideally be stored at around 50 degrees Fahrenheit (10 degrees Celsius). Do not cut eggplant before you store it as it perishes quickly once its skin has been punctured or its inner flesh exposed.

Place uncut and unwashed eggplant in a plastic bag and store in the refrigerator crisper where it will keep for a few days. If it is too large for the crisper, do not try to force it in; this will damage the skin and cause the eggplant to spoil and decay. Instead, place it on a shelf within the refrigerator.

If you purchase eggplant that is wrapped in plastic film, remove it as soon as possible since it will inhibit the eggplant from breathing and degrade its freshness.

Cucumbers

Cucumbers are scientifically known as Cucumis sativus and belong to the same botanical family as melons (including watermelon and cantaloupe) and squashes (including summer squash, winter squash, zucchini and pumpkin). Commercial production of cucumbers is usually divided into two types. "Slicing cucumbers" are produced for fresh consumption. "Pickling cucumbers" are produced for eventual processing into pickles. Slicing cucumbers are usually larger and have thicker skins, while pickling cucumbers are usually smaller and have thinner skins.

What's New and Beneficial About Cucumbers

• Researchers have long been familiar with the presence of unique polyphenols in plants called lignans, and these health-benefiting substances have been studied extensively in cruciferous vegetables (like broccoli or cabbage) and allium vegetables (like onion or garlic). Recent studies, however, have begun to pay more attention to the lignan content of other vegetables, including cucumbers. Cucumbers are now known to contain lariciresinol, pinoresinol, and secoisolariciresinol—three lignans that have a strong history of research in connection with reduced risk of cardiovascular disease as well as several cancer types, including breast, uterine, ovarian, and prostate cancers.
• Fresh extracts from cucumbers have recently been show to have both antioxidant and anti-inflammatory properties. While research in this area must still be considered preliminary—since it's only been conducted on animals in a lab setting—the findings are clear and consistent. Substances in fresh cucumber extracts help scavenge free radicals, help improve antioxidant status, inhibit the activity of pro-inflammatory enzymes like cyclo-oxygenase 2 (COX-2), and prevent overproduction of nitric oxide in situations where it could pose health risks. It's highly likely that cucumber phytonutrients play a key role in providing these antioxidant and anti-inflammatory benefits, supporting health alongside of the conventional antioxidant nutrients—including vitamin C, beta-carotene, and manganese—of which cucumbers are an important source.
• As a member of the Cucurbitaceae family of plants, cucumbers are a rich source of triterpene phytonutrients called cucurbitacins. Cucurbitacins A, B, C, D and E are all contained in fresh cucumber. They have been the subject of active and ongoing research to determine the extent and nature of their anti-cancer properties. Scientists have already determined that several different signaling pathways (for example, the JAK-STAT and MAPK pathways) required for cancer cell development and survival can be blocked by activity of cucurbitacins. We expect to see human studies that confirm the anti-cancer benefits of cucumbers in the everyday diet.

Cucumber, sliced, raw
1.00 cup
(104.00 grams)

Calories: 16
GI: very low

NutrientDRI/DV

 vitamin K18.9%

 molybdenum11.5%

 pantothenic acid5.4%

 copper4.4%

 potassium4.3%

 manganese4%

 vitamin C3.8%

 phosphorus3.5%

 magnesium3.3%

 biotin3.1%

 vitamin B12.5%

This chart graphically details the %DV that a serving of Cucumbers 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 Cucumbers can be found in the Food Rating System Chart. A link that takes you to the In-Depth Nutritional Profile for Cucumbers, featuring information over 80 nutrients, can be found under the Food Rating System Chart.

• Health Benefits
• Description
• History
• How to Select and Store
• Tips for Preparing and Cooking
• How to Enjoy
• Individual Concerns
• Nutritional Profile
• References

Health Benefits

Cucumbers have not received as much press as other vegetables in terms of health benefits, but this widely cultivated food provides us with a unique combination of nutrients. At the top of the phytonutrient list for cucumbers are its cucurbitacins, lignans, and flavonoids. These three types of phytonutrients found in cucumbers provide us with valuable antioxidant, anti-inflammatory, and anti-cancer benefits. Specific phytonutrients provided by cucumbers include

Flavonoids

• apigenin
• a luleolin
• a quercetin
• a kaempferol

Lignans

• pinoresinol
• lariciresinol
• secoisolariciresinol

Triterpenes

• cucurbitacin A
• cucurbitacin B
• cucurbitacin C
• cucurbitacin D

Details about the best-researched health benefits of cucumbers are provided in the paragraphs below.

Antioxidant & Anti-Inflammatory Benefits

Cucumbers are a valuable source of conventional antioxidant nutrients including vitamin C, beta-carotene, and manganese. In addition, cucumbers contain numerous flavonoid antioxidants, including quercetin, apigenin, luteolin, and kaempferol. In animal studies, fresh extracts from cucumber have been shown to provide specific antioxidant benefits, including increased scavenging of free radicals and increased overall antioxidant capacity. Fresh cucumber extracts have also been shown to reduce unwanted inflammation in animal studies. Cucumber accomplishes this task by inhibiting activity of pro-inflammatory enzymes like cyclo-oxygenase 2 (COX-2), and by preventing overproduction of nitric oxide in situations where it could increase the likelihood of excessive inflammation.

Anti-Cancer Benefits

Research on the anti-cancer benefits of cucumber is still in its preliminary stage and has been restricted thus far to lab and animal studies. Interestingly, however, many pharmaceutical companies are actively studying one group of compounds found in cucumber—called cucurbitacins—in the hope that their research may lead to development of new anti-cancer drugs. Cucurbitacins belong to a large family of phytonutrients called triterpenes. Cucurbitacins A, B, C, D and E have all been identified within fresh cucumber. Researchers have determined that several different signaling pathways (for example, the JAK-STAT and MAPK pathways) required for cancer cell development and cancer cell survival can be blocked by activity of cucurbitacins. Eventually, we expect to see human studies that confirm the anti-cancer benefits of cucumbers when consumed in a normal, everyday meal plan.

A second group of cucumber phytonutrients known to provide anti-cancer benefits are its lignans. The lignans pinoresinol, lariciresinol, and secoisolariciresinol have all been identified within cucumber. Interestingly, the role of these plant lignans in cancer protection involves the role of bacteria in our digestive tract. When we consume plant lignans like those found in cucumber, bacteria in our digestive tract take hold of these lignans and convert them into enterolignans like enterodiol and enterolactone. Enterolignans have the ability to bind onto estrogen receptors and can have both pro-estrogenic and anti-estrogenic effects. Reduced risk of estrogen-related cancers, including cancers of the breast, ovary, uterus, and prostate has been associated with intake of dietary lignans from plant foods like cucumber.

Description

Even though long, dark green, smooth-skinned garden cucumbers are familiar vegetables in the produce sections of most groceries, cucumbers actually come in a wide variety of colors, sizes, shapes and textures. You'll find white, yellow, and even orange-colored cucumbers, and they may be short, slightly oval, or even round in shape. Their skins can be smooth and thin, or thick and rough. In a technical sense, cucumbers are actually fruits, not vegetables. (Fruits are parts of flowering plants that come from the ovary.) But we've become accustomed to thinking and referring to cucumbers as vegetables.

All cucumbers belong to the botanical plant family called Curcubitaceae. This broad family of plants includes melons and squashes. The cucumbers we're most familiar with in the grocery store belong to the specific genus/species group, Cucumis sativus.

While there are literally hundreds of different varieties of Cucumis sativus, virtually all can be divided into two basic types: slicing and pickling. Slicing cucumbers include all varieties that are cultivated for consumption in fresh form. In the United States, commonly planted varieties of slicing cucumber include Dasher, Conquistador, Slicemaster, Victory, Comet, Burpee Hybrid, and Sprint. These varieties tend to be fairly large in size and thick-skinned. Their size makes them easier for slicing, and their thick skin makes them easier to transport in whole food form without damage. (In many other countries, however, slicing cucumbers may be smaller in size and may be much more thinly skinned.)

Pickling cucumbers include all varieties that are cultivated not for consumption in fresh form, but for processing into pickles. In the United States, commonly planted varieties of pickling cucumber include Royal, Calypso, Pioneer, Bounty, Regal, Duke, and Blitz. Some of these pickling varieties are black-spine types (in reference to the texture of their outer skin) and some are white-spine. While pickling cucumbers can always be eaten fresh, their smaller size and generally thinner skins make them easier to ferment and preserve/jar.

Pickling is a process than can be used for many different foods. It's not limited to cucumbers and or even to the vegetable food group. In general, the word "pickling" refers to a method of preventing food spoilage that involves soaking in a liquid and/or fermenting.

While the language used to describe pickles can be very confusing, there are only two basic types of pickles: fermented and non-fermented. Fermenting is a process in which fresh foods (in this case cucumbers) are allowed to soak in a solution for an extended period of time that allows microorganisms to make changes in the food. Among these changes is a build-up of lactic acid that serves to protect the pickles from spoilage. When fermented in an appropriate solution, fresh foods like cucumbers can be transformed in a way that greatly increases their shelf life. Cucumbers are typically fermented in brine (water that's been highly saturated in salt). In fact, the word "pickle" actually comes from the Dutch "pekel" meaning brine. Alongside of salt, pickling brines often contain other ingredients, including vinegar, dill seed, garlic, and lime (calcium hydroxide or calcium oxide). "Dill pickles" get their name from the addition of dill seed to the brine. "Kosher dills" are brined not only with dill, but also with garlic. (One important note in this regard: "kosher dills" are not necessarily pickled cucumbers that have been prepared according to kosher dietary laws. The word "kosher" in their name often refers to a general style of preparation in which a good bit of garlic has been used in the brining process. If you are seeking pickles that have been prepared according to kosher dietary laws, look for "certified kosher" on the label, not just "kosher" or "kosher-style.")

Fermented pickles are often called "brined pickles," but here's where confusion can set it. These two terms aren't truly interchangeable since some brined pickles are "quick brined" and haven't been given time for fermentation. When pickles are "quick brined," the brining solution usually contains a significant amount of vinegar, and it's this added vinegar that prevents the pickles from spoiling, not build up of lactic acid through the microbial fermentation process. Non-fermented pickles of all kinds—often referred to as "quick pickled"—rely on the addition of vinegar or another highly-acidic solution to prevent spoilage. "Quick pickling" with the use of vinegar can be accomplished in a matter of days. Pickling by fermentation usually takes a minimum of several weeks. If you would like to learn more about how pickled cucumbers compare in nutritional value to raw cucumbers, see this Q+A .

While genetically engineered cucumbers do exist, genetic engineering is not responsible for the existence of seedless varieties of cucumbers. Through a natural process called parthenogenesis, cucumber plants can fruit without pollen. In the absence of pollen, seeds do not develop in the fruit. While some people have a personal preference for seedless cucumbers, it's worth remembering that cucumber seeds are rich source of cucumber nutrients that are sometimes absent in the pulp and skin.

Sometimes you will hear the word "gherkin" being used to refer to cucumbers and pickles. This word can be used to describe a variety of cucumber that comes from the same plant species (Cucumis sativus) that is the source of most other cucumber varieties found in the grocery. But the term "gherkin" can also be used to describe a cucumber variety that comes from a different species of plant (Cucumis anguiria).

History

Cucumber plants naturally thrive in both temperate and tropical environments, and generally require temperatures between 60-90°F/15-33°C. For this reason, they are native to many regions of the world. In evolutionary terms, the first cucumbers were likely to have originated in Western Asia (and perhaps more specifically in India) or parts of the Middle East. Cucumbers are mentioned in the legend of Gilgamesh—a Uruk king who lived around 2500 BC in what is now Iraq and Kuwait. It was approximately 3,300 years later when cucumber cultivation spread to parts of Europe, including France. And it was not until the time of the European colonists that cucumbers finally appeared in North America in the 1500's.

Today, the states of Florida and California are able to provide U.S. consumers with fresh cucumbers for most of the year (from March through November). Imported cucumbers from Mexico are commonly found in groceries during the winter months of December, January, and February. In California alone, about 6,600 acres are planted with slicing cucumber varieties and 4,400 with pickling cucumbers. Worldwide, China is by far the largest producer of cucumbers, and provides about two-thirds of the global supply. Iran, Turkey, Russia, Egypt, Spain, Mexico, the Ukraine, Japan, Indonesia, and the U.S. all participate in the world cucumber market, with an especially high number of exports coming from Iran, Mexico, and Spain. Annual production of cucumbers worldwide is approximately 84 billion pounds.

How to Select and Store

Since cucumbers can be very sensitive to heat, you'll be on safer grounds if you choose those that are displayed in refrigerated cases in the market. They should be firm, rounded at their edges, and their color should be a bright medium to dark green. Avoid cucumbers that are yellow, puffy, have sunken water-soaked areas, or are wrinkled at their tips.

We address the issue of seeds and skins in our "Healthiest Way of Preparing Cucumbers" section below. But during the selection process, you may find it helpful to know that thin-skinned cucumbers will generally have fewer seeds than those that are thick-skinned.

Cucumbers should be stored in the refrigerator where they will keep for several days. If you do not use the entire cucumber during one meal, place it in a tightly sealed container so that it does not become dried out. For maximum quality, cucumber should be used within one or two days. Cucumbers should not be left out at room temperature for too long as this will cause them to wilt and become limp.

Corn

What food is more synonymous with summer than freshly picked corn on the cob? Corn grows in "ears," each of which is covered in rows of kernels that are then protected by the silk-like threads called "corn silk" and encased in a husk. Corn is known scientifically as Zea mays. This moniker reflects its traditional name, maize, by which it was known to the Native Americans as well as many other cultures throughout the world. Although we often associate corn with the color yellow, it actually comes in host of different varieties featuring an array of different colors, including red, pink, black, purple, and blue. Although corn is now available in markets year-round, it is the locally grown varieties that you can purchase during the summer months that not only tastes the best but are usually the least expensive.

What's New and Beneficial about Corn

• You can get health-supportive antioxidant benefits from all varieties of corn, including white, yellow, blue, purple and red corn. But recent research has shown the antioxidant benefits from different varieties of corn actually come from different combinations of phytonutrients. In the case of yellow corn, it's the antioxidant carotenoids leading the way, with especially high concentrations of lutein and zeaxanthin. In the case of blue corn, it's the anthocyanins. There's one particular hydroxybenzoic acid in purple corn—protocatechuic acid—that's also been recently linked to the strong antioxidant activity in this corn variety.
• In research on carotenoid antioxidants in food, there has been ongoing debate over the availability of all carotenoids in any particular food if one or two specific carotenoids are present in unusually high amounts. Because yellow corn is a high-carotenoid food that contains highly differing amounts of individual carotenoids, researchers have long wondered whether it is possible to get health benefits from all of the carotenoids in yellow corn when their concentrations are sometimes so different. In yellow cornmeal, the carotenoids lutein and zeaxanthin fall into the high concentration category and reach a level of 1,355 micrograms per 100 grams. That level is nearly 14 times as high as the level of beta-carotene (97 micrograms per 100 grams). But thanks to recent research, we now know that absorption of beta-carotene from yellow cornmeal is only mildly compromised by the high levels of lutein and zeaxanthin in the cornmeal. In other words, in terms of carotenoid nourishment, we appear to get health benefits from all of corn's diverse carotenoids!
• We correctly think about corn as a good source of fiber. Corn is a food that gives us plenty of chewing satisfaction, and its high ratio of insoluble-to-soluble fiber is partly the reason. Past researchers have not been clear, however, about the ability of corn fiber to nourish our lower digestive tract. When you look at foods as a whole, they contain many different types of fiber, and when certain types of fiber reach the lower part of our large intestine (especially certain types of soluble fiber) they can be metabolized by intestinal bacteria into short chain fatty acids (SCFAs). This process not only helps support healthy populations of friendly bacteria in our large intestine, but also provides a direct supply of energy (in the form of SCFAs) to the cells that line our large intestine. With this benefit of this extra SCFA energy supply, our intestinal cells can stay healthier and function at a lower risk of becoming cancerous. Recent research has shown that corn can support the growth of friendly bacteria in our large intestine and can also be transformed by these bacteria into SCFAs. These SCFAs can supply energy to our intestinal cells and thereby help lower our risk of colon cancer. The amount of corn fiber analyzed in recent studies has been relatively high at 12 grams per day. That's the same amount provided by about 2.5 cups of fresh corn. While that amount might be more than you would consume at a single meal, it's an amount that you might easily consume over the course of several days. We suspect that future research will demonstrate the risk-reducing effects of smaller amounts of corn consumed over a longer period of time.

Corn, yellow, cooked
1.00 each
(77.00 grams)

Calories: 74
GI: medium

NutrientDRI/DV

 pantothenic acid12.2%

 phosphorus8.4%

 vitamin B38.1%

 fiber7.4%

 manganese6.5%

 vitamin B66.4%

This chart graphically details the %DV that a serving of Corn 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 Corn can be found in the Food Rating System Chart. A link that takes you to the In-Depth Nutritional Profile for Corn, featuring information over 80 nutrients, can be found under the Food Rating System Chart.

• Health Benefits
• Description
• History
• How to Select and Store
• Tips for Preparing and Cooking
• How to Enjoy
• Individual Concerns
• Nutritional Profile
• References

Health Benefits

Corn has gathered a diverse reputation in the U.S. For some people, corn is a "staple" food that provides the foundation for tortillas, burritos, or polenta. For others, corn is a "snack" food that comes in the form of popcorn and corn chips. For still others, corn is a "special summertime food" that is essential at barbecues and cookouts. But regardless of its reputation, corn is seldom considered in the U.S. as a unique source of health benefits. Yet that's exactly what research results are telling us about this amazing grain.

Antioxidant Benefits

While it might sound surprising to some people who are used to thinking about corn as a plain, staple food, or a snack food, or a summertime party food, corn is actually a unique phytonutrient-rich food that provides us with well-documented antioxidant benefits. In terms of conventional antioxidant nutrients, corn is a good source of the mineral manganese. But it is corn's phytonutrients that have taken center stage in the antioxidant research on corn. When all varieties of corn are considered as a group, the list of corn's key antioxidant nutrients appears as follows:

Antioxidant Phytonutrients in Corn

• anthocyanins
• beta-carotene
• caffeic acid
• coumaric acid
• ferulic acid
• lutein
• syringic acid
• vanillic acid
• protocatechuic acid
• zeaxanthin

Different varieties of corn highlight different combinations of antioxidant phytonutrients. In the case of yellow corn, carotenoids lead the way and provide especially high concentrations of lutein and zeaxanthin. Blue corn is unique in its anthocyanin antioxidants. One particular hydroxybenzoic acid in purple corn—protocatechuic acid—has recently been linked to the strong antioxidant activity in this corn variety.

Most studies of disease and risk reduction from dietary antioxidant intake have not looked specifically at corn and its impressive combination of antioxidants. However, in several small-scale studies, corn has been directly mentioned as a food that was important in overall antioxidant protection and a contributing factor in the decreased risk of cardiovascular problems. Some of the mechanisms for decreased cardio risk may be related to other properties of corn's phytonutrients that go beyond their antioxidant properties. For example, some of the phytonutrients in corn may be able to inhibit angiotensin-I converting enzyme (ACE) and help lower risk of high blood pressure in this way. We suspect that future studies will further confirm the important role of corn's phytonutrients in reduction of risk for a variety of health problems, and that antioxidant and other properties will play a key role in this risk reduction.

One great piece of news about corn's antioxidants involves the practice of drying corn (still on the cob) or separated corn kernels. Research studies have shown that the drying of corn in temperature ranges as high as 150°-200°F (65°-93°C) does not significantly lower corn's antioxidant capacity. This research confirms the wisdom of many North American and Mesoamerican cultures which relied on naturally-dried corn in the preparation of meal foods, especially during the winter months.

Interestingly, recent research has determined that the percent of amylose starch found in corn may be related to its antioxidant capacity. Higher amylose corn varieties have shown higher antioxidant capacity in some preliminary studies. While the jury is out on the exact meaning of these findings, this research reminds us to keep an open mind about the potential importance of antioxidant health benefits from corn.

Digestive Benefits

Anyone who has eaten fresh corn-on-the-cob or freshly popped popcorn knows how satisfying this food can be to chew. Some of that satisfaction comes from corn's fiber content. At 4.6 grams of fiber per cup, corn is a good fiber source, and in research studies, corn intake is often associated with good overall fiber intake. For example, persons who eat popcorn tend to have 2-3 times more overall whole grain intake than persons who do not eat popcorn, and they also tend to have higher overall fiber intake as well.

Corn fiber is one of the keys to its well-documented digestive benefits. Recent research has shown that corn can support the growth of friendly bacteria in our large intestine and can also be transformed by these bacteria into short chain fatty acids, or SCFAs. These SCFAs can supply energy to our intestinal cells and thereby help lower our risk of intestinal problems, including our risk of colon cancer. The amount of corn fiber analyzed in recent studies has been relatively high at 12 grams per day. That's the same amount provided by about 2.5 cups of fresh corn. While that amount might be more than any person would consume in a single meal, it's an amount that a person might easily eat over the course of several days. We suspect that future research will demonstrate the risk-reducing effects of smaller amounts of corn consumed over a longer period of time.

Blood Sugar Benefits

Given its good fiber content, its ability to provide many B-complex vitamins including vitamins B1, B5 and folic acid, and its notable protein content (about 5-6 grams per cup), corn is a food that would be expected to provide blood sugar benefits. Fiber and protein are key macronutrients for stabilizing the passage of food through our digestive tract. Sufficient fiber and protein content in a food helps prevent too rapid or too slow digestion of that food. By evening out the pace of digestion, protein and fiber also help prevent too rapid or too slow uptake of sugar from the digestive tract up into the bloodstream. Once the uptake of sugar is steadied, it is easier to avoid sudden spikes or drops in blood sugar.

Consumption of corn in ordinary amounts of 1-2 cups has been shown to be associated with better blood sugar control in both type 1 and type 2 diabetes. Fasting glucose and fasting insulin levels have been used to verify these blood sugar benefits. Interestingly, in elementary school-age and teenage youths already diagnosed with type 1 diabetes, whole grain cornbread has emerged in one study as the whole grain food with the highest acceptability among all whole grain foods. Youth participants in the study who consumed whole grain cornbread were also less likely to consume fast foods.

Other Benefits

In countries outside of the U.S., numerous studies have examined the ability of corn to improve overall nourishment, especially when combined with legumes. Researchers conducting these studies have been interested in absorption of minerals like zinc, calcium and iron, as well as overall energy and protein intake. Maize (corn)-bean meals (typically consumed in the form of porridge that combines these foods) have been shown to help improve overall nutrient status and to help provide outstanding nutrient richness in the diet.

One fascinating new area of research on corn involves its potential anti-HIV activity. Lectins are special proteins found in virtually all foods (and for that matter, in virtually all organisms) that can bind onto carbohydrates or onto carbohydrate receptors that are found on cell membranes. In the case of some micro-organisms (including the HIV virus), the binding of lectins onto sugars has been shown to help inhibit activity of the virus. One specific lectin found in corn (called GNAmaize) has preliminarily been shown to possess this HIV-inhibiting property. Of course, much more research is needed to determine the relationship between everyday consumption of corn as a whole food and HIV infection risk.

Description

While the kernels that we commonly call "corn" are technically the fruit of the plant Zea mays, corn is widely classified as a grain and is typically included in research studies of whole grain foods like wheat, oats, and barley. Throughout much of the world, corn is referred to as "maize." In many ways, "maize" is the best way of describing this plant since it was first domesticated in Mesoamerica over 8,000 years ago and was originally described using the Spanish word "maiz." This remarkable food took on sacred qualities for many Central American and South American cultures, as well as many Native American tribes in what is now the United States.

All types of corn come from the same genus and species of plant, Zea mays. However, within this genus and species, there are well over 100 subspecies and varieties. Many different subspecies are most familiar to consumers in terms of color. White, yellow, pink, red, blue, purple, and black corn are all varieties of Zea mays. Each of these varieties contains its own unique health-supportive combination of antioxidant phytonutrients. In the case of yellow corn, there's a greater concentration of carotenoids, especially lutein and zeaxanthin. With blue corn, there's a richer supply of anthocyanins. In purple corn, there's one particular hydroxybenzoic acid—protocatechuic acid—that's been recently linked to this variety's antioxidant capacity.

History

Perhaps no other food has been more closely identified with the Americas than corn. Both the Mayan and the Olmec civilizations that date back to 2000-1500 BC in what is now Mexico and Central America (commonly called Mesoamerica) had not only adopted maize as a staple food in the diet but had also developed a reverence for maize that was expressed in everyday rituals, religious ceremonies, and in the arts. The first domestication of maize in Mesoamerica actually dates back even further, to 9000-8000 BC. Corn was equally valued by Native American tribes living in North America, although tribal wisdom about corn was largely ignored by European colonists in the 15th and 16th centuries AD.

By the time Columbus and other explorers arrived in North America, corn was already an integral part of Native American cuisine. However, many colonists ignored Native American traditions related to corn—including the pot ash tradition—and later fell victim to the vitamin B3 deficiency disease called pellagra. (When cooking corn and cornmeal, Native Americans had developed a practice of incorporating ash from the fire into the food, and the mineral mix in this ash increased the bioavailability of vitamin B3 from the corn. The addition of lime in the form of calcium hydroxide to tortillas still serves this purpose today.)

While the average U.S. adult does not share the reverence for corn that characterized the practices of Native Americans and indigenous peoples of Mesoamerica, there is still an amazing influence of corn on the U.S. diet. Forty percent of all processed, pre-packaged foods sold in U.S. groceries currently contain some processed component of corn, although this component is most often high fructose corn syrup (HFCS). Per capita consumption of corn in all forms is approximately 160 pounds in the U.S. (and approximately 60-65 pounds come in the form of HFCS). U.S. farmers grow about 40% of all corn produced worldwide. An important region of the U.S. is still identified as the "Corn Belt." This region is typically defined as including Iowa, Illinois, the eastern parts of Nebraska and Kansas as well as North and South Dakota, the southern part of Minnesota, and parts of northern Missouri as well as Ohio and Indiana. However, Iowa, Illinois, Nebraska and Minnesota remain the top producers of corn in the U.S. and provide over 50% of all U.S. corn crops.

An increasing trend in U.S. production of corn has been cultivation for non-food purposes. Addition of ethanol to gasoline and biofuel production have been two important factors in the shift away from food-based cultivation of corn. The cultivation of corn for ethanol production has also led to an increased supply of ethanol by-products that have found their way into the marketplace. An example here is distillers dried grains, or DDGs. DDGs have already become an important part of livestock feed, along with other corn components.

Along with the United States, other important commercial producers of corn currently include China, Brazil, Mexico, Russia, Ukraine, Romania, and South Africa.

How to Select and Store

From a food safety standpoint, we recommend selection of corn that has not been exposed to any substantial amount of heat. Exposure to excess heat can increase the susceptibility of fresh corn to microbial contamination. If you are shopping in the grocery store, your safest bet is corn that is being displayed in a refrigerated produce bin. Next safest would be corn that, while not refrigerated, is still being displayed in a cool store location, out of direct sun and not near a heat source. These same recommendations apply for corn in a farmer's market or roadside stand. Here display of corn in the shade and out of direct sunlight can be important from a food safety standpoint.

Look for corn whose husks are fresh and green and not dried out. They should envelope the ear and not fit too loosely around it. To examine the kernels, gently pull back on part of the husk. The kernels should be plump and tightly arranged in rows. Due to changes that have occurred over time in commercial corn production, corn has become a food where quality is especially important. Over 70% of all corn found in U.S. grocery stores has been genetically modified in the form of herbicide-tolerant, or HT corn, or the form of insect-resistant, or Bt corn. (Bt corn gets its name from the transfer of a gene from the soil bacterium, Bacillus thuringiensis, into the corn. A protein toxin produced by this bacterium helps to kill certain insects that might otherwise eat the corn.) While there is no large scale human research on GE corn and its health impact, we share the concern of many researchers about the introduction of novel proteins into food and their potential for increasing risk of adverse reactions, including food allergies. One way to avoid these potential GE risks is to select certified organic corn, since GE modifications are not allowed in certified organic food.

While not a "Dirty Dozen" food in terms of pesticide residues as evaluated by the U.S. Environmental Working Group (EWG), non-organic, conventionally grown corn has repeatedly been shown to contain organochlorine pesticide residues. In one study, 19 different pesticide residues were found on samples of conventionally grown corn. Like potential GE risks, potential pesticide risks can be avoided through selection of certified organic corn.

Traditionally to enjoy the optimal sweetness of fresh corn, it was recommended to eat it the day of purchase. New varieties allow you 3 days to still enjoy its full flavor. Store corn in an air-tight container or tightly wrapped plastic bag in the refrigerator if you do not intend to cook it on the day of purchase. Do not remove its husk since this will protect its flavor. Fresh corn freezes well if placed in heavy-duty freezer bags. To prepare whole ears for freezing, blanch them first for five minutes depending. If you just want to freeze the kernels, first blanch the ears and then cut the kernels off the cob at about three-quarters of their depths. Frozen whole corn on the cob will keep for up to one year, while the kernels can be frozen for two to three months.

Collard greens

What's New and Beneficial About Collard Greens

• The cholesterol-lowering ability of collard greens may be the greatest of all commonly eaten cruciferous vegetables. In a recent study, steamed collard greens outshined steamed kale, mustard greens, broccoli, Brussels sprouts, and cabbage in terms of its ability to bind bile acids in the digestive tract. When this bile acid binding takes place, it is easier for the bile acids to be excreted from the body. Since bile acids are made from cholesterol, the net impact of this bile acid binding is a lowering of the body's cholesterol level. It's worth noting that steamed collards show much greater bile acid binding ability than raw collards.
• We get unique health benefits from collard greens in the form of cancer protection. The cancer-preventive properties of collard greens may be largely related to 4 specific glucosinolates found in this cruciferous vegetable: glucoraphanin, sinigrin, gluconasturtiian, and glucotropaeolin. Each of these glucosinolates can be converted into an isothiocyanate (ITC) that helps lower our cancer risk by supporting our detox and anti-inflammatory systems.

WHFoods Recommendations

You'll want to include collard greens as one of the cruciferous vegetables you eat on a regular basis if you want to receive the fantastic health benefits provided by the cruciferous vegetable family. At a minimum, include cruciferous vegetables as part of your diet 2-3 times per week, and make the serving size at least 1-1/2 cups. Even better from a health standpoint, enjoy collard greens and other vegetables from the cruciferous vegetable group 4-5 times per week, and increase your serving size to 2 cups.

It is very important not to overcook collard greens. Like other cruciferous vegetables overcooked collard greens will begin to emit the unpleasant sulfur smell associated with overcooking. To help collard greens to cook more quickly, evenly slice the leaves into 1/2-inch slices and the stems into 1/4-inch pieces. Let them sit for at least 5 minutes to bring out the health-promoting qualities and steam for 5 minutes. Serve with ourMediterranean Dressing. See 5-Minute Collard Greens. 

Collard Greens, chopped, cooked
1.00 cup
(190.00 grams)

Calories: 63
GI: very low

NutrientDRI/DV

 vitamin K858.3%

 vitamin A80.2%

 manganese48.5%

 vitamin C46.1%

 fiber30.4%

 calcium26.7%

 choline17.1%

 vitamin B215.3%

 vitamin B614.1%

 iron11.9%

 vitamin E11.1%

 copper11.1%

 protein10.3%

 magnesium9.9%

 phosphorus8.6%

 pantothenic acid8.2%

 folate7.6%

 omega-3 fats7.5%

 vitamin B36.8%

 vitamin B16.6%

 potassium6.3%

This chart graphically details the %DV that a serving of Collard greens 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 Collard greens can be found in the Food Rating System Chart. A link that takes you to the In-Depth Nutritional Profile for Collard greens, featuring information over 80 nutrients, can be found under the Food Rating System Chart.

• Health Benefits
• Description
• History
• How to Select and Store
• Tips for Preparing and Cooking
• How to Enjoy
• Individual Concerns
• Nutritional Profile
• References

Health Benefits

Unlike broccoli and kale and cabbage, you won't find many research studies devoted to the specific health benefits of collard greens. However, collard greens are sometimes included in a longer list of cruciferous vegetables that are lumped together and examined for the health benefits they provide. Based on a very small number of studies looking specifically at collard greens, and a larger number of studies looking at cruciferous vegetables as a group (and including collard greens on the list of vegetables studied), cancer prevention appears to be a standout area for collard greens with respect to their health benefits.

This connection between collard greens and cancer prevention should not be surprising since collard greens provide special nutrient support for three body systems that are closely connected with cancer development as well as cancer prevention. These three systems are (1) the body's detox system, (2) its antioxidant system, and (3) its inflammatory/anti-inflammatory system. Chronic imbalances in any of these three systems can increase risk of cancer, and when imbalances in all three systems occur simultaneously, the risk of cancer increases significantly. Among all types of cancer, prevention of the following cancer types is most closely associated with intake of collard greens: bladder cancer, breast cancer, colon cancer, lung cancer, prostate cancer, and ovarian cancer.

Detox Support Provided by Collard Greens

The detox support provided by collard greens includes antioxidant nutrients to boost Phase 1 detoxification activities and sulfur-containing nutrients to boost Phase 2 activities. Collard greens also contain phytonutrients called glucosinolates that can help activate detoxification enzymes and regulate their activity. Four key glucosinolates that have been clearly identified in collard greens in significant amounts are glucobrassicin, glucoraphanin, gluconasturtiian, and glucotropaeolin.

If we fail to give our body's detox system adequate nutritional support, yet continue to expose ourselves to unwanted toxins through our lifestyle and our dietary choices, we can place our bodies at increased risk of toxin-related damage that can eventually increase our cells' risk of becoming cancerous. That's one of the reasons it's so important to bring collard greens and other cruciferous vegetables into our diet on a regular basis.

The Antioxidant Benefits of Collard Greens

As an excellent source of vitamin C, vitamin A (in the form of carotenoids), and manganese, and a good source of vitamin E, collard greens provide us with 4 core conventional antioxidants. But the antioxidant support provided by collard greens extends far beyond the conventional nutrients into the realm of phytonutrients. Caffeic acid, ferulic acid, quercetin, and kaempferol are among the key antioxidant phytonutrients provided by collard greens. This broad spectrum antioxidant support helps lower the risk of oxidative stress in our cells. Chronic oxidative stress—meaning chronic presence over overly reactive oxygen-containing molecules and cumulative damage to our cells by these molecules—is a risk factor for development of most cancer types. By providing us with such a great array of antioxidant nutrients, collard greens help lower our cancer risk by helping us avoid chronic and unwanted oxidative stress.

Collard Greens' Anti-inflammatory Benefits

As an excellent source of vitamin K and a good source of omega-3 fatty acids (in the form of alpha-linolenic acid, or ALA), collard greens provide us with two hallmark anti-inflammatory nutrients. Vitamin K acts as a direct regulator of our inflammatory response, and ALA is the building block for several of the body's most widely-used families of anti-inflammatory messaging molecules. In addition to these two anti-inflammatory components, one of the glucosinolates found in collard greens—glucobrassicin—can be readily converted into an isothiocyanate molecule called I3C, or indole-3-carbinol (I3C). I3C is an anti-inflammatory compound that can actually operate at the genetic level, and by doing so, prevent the initiation of inflammatory responses at a very early stage.

Like chronic oxidative stress and chronic weakened detox ability, chronic unwanted inflammation can significantly increase our risk of cancers and other chronic diseases (especially cardiovascular diseases).

Collard Greens and Cardiovascular Support

Researchers have looked at a variety of cardiovascular problems—including heart attack, ischemic heart disease, and atherosclerosis—and found preliminary evidence of an ability on the part of cruciferous vegetables to lower our risk of these health problems. Yet regardless of the specific cardiovascular problem, it is one particular type of cardiovascular benefit that has most interested researchers, and that benefit is the anti-inflammatory nature of collard greens and their fellow cruciferous vegetables. Scientists have not always viewed cardiovascular problems as having a central inflammatory component, but the role of unwanted inflammation in creating problems for our blood vessels and circulation has become increasingly fundamental to an understanding of cardiovascular diseases. Of particular interest here has been the isothiocyanate (ITC) sulforaphane, which is made from glucoraphanin (a glucosinolate) found in collard greens. Not only does this ITC trigger anti-inflammatory activity in our cardiovascular system, it may also be able to help prevent and even possibly help reverse blood vessel damage.

A second area you can count on collard greens for cardiovascular support involves their cholesterol-lowering ability. Our liver uses cholesterol as a basic building block to product bile acids. Bile acids are specialized molecules that aid in the digestion and absorption of fat through a process called emulsification. These molecules are typically stored in fluid in our gall bladder, and when we eat a fat-containing meal, they get released into the intestine where they help ready the fat for interaction with enzymes and eventual absorption up into the body. When we eat collard greens, fiber-related nutrients in this cruciferous vegetable bind together with some of the bile acids in the intestine in such a way that they simply stay inside the intestine and pass out of our body in a bowel movement, rather than getting absorbed along with the fat they have emulsified. When this happens, our liver needs to replace the lost bile acids by drawing upon our existing supply of cholesterol, and as a result, our cholesterol level drops down. Collard greens provide us with this cholesterol-lowering benefit whether they are raw or cooked. However, a recent study has shown that the cholesterol-lowering ability of raw collard greens improves significantly when they are steamed. In fact, when the cholesterol-lowering ability of steamed collard greens was compared with the cholesterol-lowering ability of the prescription drug cholestyramine (a medication that is taken for the purpose of lowering cholesterol), collard greens bound 46% as many bile acids (based on a standard of comparison involving total dietary fiber).

In addition to the support factors described above, it is impossible to talk about the cardiovascular benefits of collard greens without mentioning their exceptional folate content. Although this cruciferous vegetable scores a rating of "excellent" in our food rating system, we would like to point out just how "excellent" excellent is when you're talking about collards. These greens provide more than 350 micrograms of folate in every hundred calories. That's 50% more than the amount provided by 100 calories' of broccoli, 100% more than the amount provided by 100 calories' of Brussels sprouts, 3 times the amount provided by 100 calories' of cabbage, and over 7 times the amount provided by 100 calories' of kale. Folate is a critical B-vitamin for support of cardiovascular health, including its key role in prevention of homocysteine build-up (called hyperhomocysteinemia).

Collard Greens and Digestive Support

The fiber content of collard greens—over 7 grams in every cup—makes this cruciferous vegetable a natural choice for digestive system support. Yet the fiber content of collard greens is only one of their digestive support mechanisms. Researchers have determined that the sulforaphane made from a glucosinolate in collard greens (glucoraphanin) helps protect the health of our stomach lining by preventing bacterial overgrowth ofHelicobacter pylori in our stomach or too much clinging by this bacterium to our stomach wall.

Other Health Benefits From Collard Greens

The anti-inflammatory nature of glucosinolates/isothiocyanates and other nutrients found in collard greens has been the basis for new research on inflammation-related health problems and the potential role of collard greens in their prevention. Current and potentially promising research is underway to examine the benefits of collard greens in relationship to our risk of the following inflammation-related conditions: Crohn's disease, inflammatory bowel disease, insulin resistance, irritable bowel syndrome, metabolic syndrome, obesity, rheumatoid arthritis, type 2 diabetes, and ulcerative colitis.

Description

All cruciferous vegetables provide integrated nourishment across a wide variety of nutritional categories and provide broad support across a wide variety of body systems as well. For more on cruciferous vegetables see:

• Eating Healthy with Cruciferous Vegetables
• Feeling Great with Cruciferous Vegetables

Collards are leafy green vegetables that belong to the same family that includes cabbage, kale, and broccoli. While they share the same botanical name as kale, Brassica oleracea, and some resemblance, they have their own distinctive qualities. Like kale, collards are one of the non-head forming members of the Brassica family. Collards' unique appearance features dark blue green leaves that are smooth in texture and relatively broad. They lack the frilled edges that are so distinctive to their cousin kale.

Long a staple of the Southern United States, collard greens, unlike their cousins kale and mustard greens, have a very mild, almost smoky flavor. Although they are available year-round they are at their best from January through April.

History

Like kale, cauliflower and broccoli, collards are descendents of the wild cabbage, a plant thought to have been consumed as food since prehistoric times and to have originated in Asia Minor. From there it spread into Europe, being introduced by groups of Celtic wanderers around 600 B.C. Collards have been cultivated since the times of the ancient Greek and Roman civilizations. While collards may have been introduced into the United States before, the first mention of collard greens dates back to the late 17th century. Collards are an integral food in traditional southern American cuisine.

How to Select and Store

Look for collard greens that have firm, unwilted leaves that are vividly deep green in color with no signs of yellowing or browning. Leaves that are smaller in size will be more tender and have a milder flavor. They should be displayed in a chilled section in the refrigerator case to prevent them from wilting and becoming bitter.

Place collard greens in a plastic bag, removing as much of the air from the bag as possible. Store in the refrigerator where they should keep fresh for about three to five days.