Tuesday, July 3, 2012

Posted from WHFoods.org

Healthy Food Tip
The Latest News About 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.
WHFoods Recommendations
Of all of the cooking methods we tried when cooking corn, our favorite is Healthy Steaming. We think that it provides the greatest flavor and is also a method that allows for good nutrient retention.
To Healthy Steam fresh corn, fill the bottom of the steamer with 2 inches of water and bring to a rapid boil. Steam corn for 5 minutes. For extra flavor, dress with extra virgin olive oil, sea salt, and pepper. (See our Steamed Mexican Corn on the Cob recipe for details on how to prepare Healthy Steamed corn with extra flavor.
We also suggest the purchase of organically grown corn whenever possible so as to avoid corn that has been genetically modified (GM). Additionally, 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. Like potential GM risks, potential pesticide risks can be avoided through selection of certified organic corn.
Health Benefits
Corn provide numerous health benefits including:
  • Antioxidant support
  • Digestive health benefits
  • Blood sugar benefits
For more details on corn's health benefits, see this section of our corn write-up.
Nutritional Profile
Antioxidant phytonutrients are provided by all varieties of corn. The exact phytonutrient combination, however, depends on the variety itself. Yellow corn is richer in carotenoids, especially lutein and zeaxanthin. Blue corn has unique concentrations of anthocyanins. Purple corn provides unusual amounts of the hydroxybenzoic acid called protocatechuic acid. Ferulic acid, beta-carotene, vanillic acid, coumaric acid, caffeic acid, and syringic acid are other key phytonutrients provided by corn. Corn is a good source of energy-producing vitamin B1, vitamin B5, and phosphorus; heart-healthy folate and dietary fiber; and free radical-scavenging vitamin C and manganese.
For more on this nutrient-rich food, including references related to this Latest News, see our write-up on corn.
If you have any questions about today's Healthy Food Tip Ask George Your Question

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