Eggs by Design
Scientists, farmers, and food manufacturers have found ways to change the nutrient composition of eggs. Are these new-fangled eggs better for you than regular eggs?
A quick glance at the egg section of most large supermarkets gives consumers several choices. In addition to the standard white and brown eggs, you can buy eggs that are cage-free or ]]>organic]]> . Plus, you can choose ones that have increased levels of omega-3 fatty acids or vitamin E. You can also choose from a variety of egg-substitute products, most of which are refrigerated or frozen and packaged for easy use.
Eating Eggs Again
Consumers are buying eggs in record numbers—a far cry from egg consumption during the 1980s, when consumers were taught to avoid eggs and, in particular, egg yolks. There are three reasons for this recent surge in popularity. The first is current research indicating that moderate egg consumption can be part of a healthful, low-fat eating plan. The second reason is that we are eating more processed foods, which require eggs. And third is the popularity of both high-protein and vegetarian-based diets.
Understanding Nature's Design
The standard egg is an economical source of nutrition. Eggs contain 13 vitamins and minerals, including ]]>zinc]]> , ]]>iron]]> , ]]>folate]]> , ]]>vitamins A]]> , ]]>E]]> , and B complex—all this for only 75 calories! Egg protein is of such high quality that it is the standard reference for comparing the protein content of other foods. Current nutrient analyses suggest that the ]]>cholesterol]]> content of an average egg is about 213-220 mg, rather than the previously estimated 274 mg. All of this cholesterol is contained in the yolk part of the egg.
Nature delivers eggs in two colors—white and brown. Contrary to popular thinking, brown eggs are neither organic nor different in nutrition from white eggs. The breed of the hen determines the shell color. Breeds with white feathers and ear lobes lay white eggs. Hens with red feathers and ear lobes lay brown eggs.
Learning About Cage-free, Range-free, and Organic Eggs
Hens are typically caged in modern facilities with controlled temperatures, humidity, light, and air circulation. American birds are fed hormone-free, high-quality feed with automatic feeders. Fresh water is provided through self-cleaning cups and valves.
Because some consumers are opposed to this type of confinement, options such as cage-free and range-free eggs are available. These types of eggs have the same nutrient composition as the standard egg.
- Cage-free eggs are from birds that are maintained on the floor of a poultry house or barn, but are not allowed to roam free outdoors. Due to poor weather and climate, they may not have any access at all to outside areas.
- Range-free eggs are typically from birds allowed to go outdoors in the day and are housed inside at night for protection.
- Organic eggs are from hens fed rations formulated from ingredients free of herbicides, fungicides, pesticides, and commercial fertilizers. The higher production costs and lower volume of eggs per farm drives the price of organic eggs higher than that of the standard egg.
Getting the Scoop on Designer Eggs
During the past several years, scientists and egg producers have joined together to produce specialty or so-called "designer eggs." According to the Egg Nutrition Center, an industry research group, these specialty eggs account for a growing percentage of market sales.
One such egg is the high ]]>omega-3 egg]]> . Hens are fed a special oil that accumulates in the egg yolk, increasing the omega 3-fatty acids, while decreasing the saturated fat. Retail omega-3 fatty acid eggs contain three to four times the content of the standard egg.
Some scientists and nutritionists see these designer eggs as a realistic way to help Americans eat more omega-3 fatty acids, which have been shown in some studies to reduce the risk of heart disease. In fact, one egg fortified with this fatty acid provides the same content as a one-ounce serving of oily fish, such as salmon.
More Vitamin E
Some egg producers are also marketing eggs with seven times the level of vitamin E found in standard eggs. The hens are fed kelp to produce eggs with more vitamin E than most eggs. The vitamin E content of these eggs approaches 5 mg, which is the equivalent of the vitamin E found in one tablespoon of oil. Although 5 mg of vitamin E is only 33% of the recommended intake, there aren't very many sources of vitamin E that yield so few calories, because most vitamin E-rich foods are found in oil-based products. The 5 mg of vitamin E from an egg, for example, yields 75 calories versus 120 calories from the same 5 mg found in one tablespoon of oil.
Egg substitutes are another type of specialty egg. These liquid egg products are cholesterol-free, because they're made from only egg whites. The yolk is typically replaced with other ingredients, such as vegetable oil, emulsifiers, stabilizers, gums, and artificial colors, and then the product is fortified with vitamins and minerals. Egg substitutes have the added advantage of being pasteurized. This means you can use them safely in recipes that traditionally call for raw eggs, such as mayonnaise, salad dressings, eggnog, and pastry filling, without being concerned about Salmonella contamination, which can result from undercooked eggs.
Unscrambling the Cholesterol Issue
And what about the cholesterol content of these specialty eggs? The cholesterol content in the designer egg is similar to that of a regular egg, but many nutritionists believe that dietary cholesterol is less of a culprit in raising serum cholesterol levels than is overall total fat intake.
One research study from the Harvard School of Public Health suggests that healthy people who ate up to seven eggs a week were no more likely to have a ]]>heart attack]]> or ]]>stroke]]> than those who ate fewer eggs. The study tracked more than 37,000 healthy men aged 40 to 75 and 80,000 healthy women aged 34 to 59 for more than a decade. The study did note, however, that people with ]]>diabetes]]> may be at an increased risk for heart disease with a higher egg consumption.
But not all researchers concur. "Limiting the amount of dietary cholesterol from eggs and other sources is of proven benefit for the population," says Linda Van Horn, PhD, RD, of Chicago's Northwestern University Medical School Department of Preventive Medicine. She notes that during the last 40 years, Americans have reduced their intake of egg yolks and high-fat meat and dairy products and says that these changes have led to significant reduction in average blood cholesterol level and cardiovascular mortality. And while she says the current data surrounding the potential benefit from designer eggs with increased amounts of omega-3 fatty acids are "intriguing," she thinks they are "inadequate to formulate public policy regarding general or even selected use."
Finding the Right Amount for You
The American Heart Association (AHA) continues to recommend that people limit their cholesterol intake to 300 mg per day, and their whole egg consumption to 3-4 per week. Heather Earls, MPH, RD, senior director of Prevention and Healthcare Programs of the American Heart Association, recommends the use of two egg whites, or one egg white plus two teaspoons of unsaturated oil to replace a whole egg in cooking.
Earls also suggests that consumers use a cholesterol-free commercial egg substitute. The AHA does acknowledge that ]]>cholesterol]]> is only one factor associated with heart disease, and that ]]>high blood pressure]]> , diabetes, and lifestyle habits (such as smoking, diet, and exercise) contribute independently to heart disease risk.
Alberta Egg Producers
Egg industry facts. American Egg Board. Available at: http://www.aeb.org/Retailers/industry.html . Accessed October 17, 2007.
Hu FB, Stampfer MJ, Rimm EB, et al. A prospective study of egg consumption and risk of cardiovascular disease in men and women. JAMA . 1999;28:1387-1394.
Specialty eggs. Egg Nutrition Center. Available at: http://www.enc-online.org/factsheet/SpecialtyEggs1005.pdf . Accessed October 17, 2007.
Last reviewed May 2009 by ]]>Maria Adams, MS, MPH, RD]]>
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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