Grocery store shelves are filled with an almost overwhelming variety of choices, and the dairy section is no exception. Consumers can choose among brands and sizes of conventionally produced eggs or opt for cage-free, organic products. Other options for egg products include cholesterol-free, high-vitamin-E, low-cholesterol or omega-3-enhanced. You can also select eggs based on the diets of the hens that produced them — for example, hormone-free, antibiotic-free or vegetarian diets. One visible difference between eggs that influences consumer choice is the egg shell color.
The only difference between brown eggs and white eggs is the shell color, which is determined by genetics. The nutritional content of eggs is affected only by a hen's diet. Eggs from hens that are fed the same diet, whether they are brown or white, are the same nutritionally. The eggs would also have the same flavor, taste and cooking characteristics. The rise in prevalence of brown eggs on supermarket shelves is likely related to consumer's widespread, although faulty, belief that brown eggs are healthier than white. As the market for specialty eggs has grown, producers have opted to use hens that lay brown-shelled eggs to fill this niche.
Calories, Fat and Protein
Eggs are a good source of many nutrients. One large egg contains approximately 72 calories, 6 grams of protein and some healthful unsaturated fats. The total fat content of one large egg is approximately 5 grams. Eggs do contain a lot of cholesterol. The average large egg contains 186 milligrams of cholesterol, which compares to a single serving of liver, shrimp or duck meat. For people concerned about blood cholesterol levels, it is important to know that dietary cholesterol actually has less of an effect on blood cholesterol levels than do saturated fats and trans fats. No connection has been found between egg consumption and heart disease in people without diabetes. In people with diabetes, those who eat an egg every day are slightly more likely to develop heart disease. To avoid cholesterol, simply discard the yolk and eat only the egg white, since all of the cholesterol in an egg is contained in the yolk. Other options to limit cholesterol include using only one yolk with two egg whites or using pourable egg whites or yolk-free egg substitutes.
Eggs are a good source of the carotenoids lutein and zeaxanthin. People who eat higher levels of these nutrients have a lowered risk of macular degeneration, a vision problem that affects millions of older Americans. Lutein and zeaxanthin help to prevent macular degeneration by helping to filter types of light that can cause damage to the eye. Eggs are also a good source of choline. Choline is an essential nutrient that plays many important roles in the body, including in brain and memory development, and lipid transport. Recommended adequate intake levels for adults are 550 milligrams per day for men and 425 milligrams per day for women. One large egg provides 126 milligrams of choline.
Some consumers avoid brown eggs because they believe brown eggs are more likely than white eggs to have "blood spots." This is, in fact, true. About 25 percent to 30 percent of brown eggs, regardless of brand, typically contain pigmented spots or protein spots. The spots are not a sign of fertilization and do not actually contain any blood cells. They are caused when a blood vessel on the yolk surface or on the oviduct wall ruptures during egg formation. They are safe to eat, although many people prefer to discard the egg or remove the spot with a knife. While these spots occur in both white and brown eggs, they are more likely to be caught and discarded during inspections of white eggs, since the shells are more transparent.
- USDA National Nutrient Database for Standard Reference: Egg, Whole, Raw, Fresh
- American Journal of Clinical Nutrition: Egg Consumption in Relation to Risk of Cardiovascular Disease and Diabetes: A Systematic Review and Meta-analysis
- The Journal of the American Medical Association: Dietary Carotenoids, Vitamins A, C, and E, and Advanced Age-Related Macular Degeneration
- Vision Research: Differential Spectral Photic Damage to Primate Cones
- Nutrition Reviews: Choline: An Essential Nutrient for Public Health
- Oregon State University, Linus Pauling Institute: Micronutrient Information Center - Choline
- International Hatchery Practice: Breeding Chickens to Meet Egg Quality Needs