The old adage "you are what you eat" certainly holds true when considering the nutritional value of eggs. Since the 1970s, studies have indicated that eggs from hens with access to pasture are better for you than eggs from birds kept in cages (see References 2, page 4). Free-range hens that eat a healthy, natural diet pass on that benefit to you in the form of more nutritious eggs.
Free-range chickens must have access to the outdoors, according to U.S. Department of Agriculture regulations, whereas growers raise conventional poultry confined indoors in cages (see References 1). Pasture-raised hens eat a diet of grass and bugs in addition to their grain diet. Conventionally raised birds, on the other hand, are fed a strictly grain diet. Consumers should note, however, that regulations do not require that free-range hens have access to pasture, and studies comparing the hens' diet to the nutritional value of their eggs compare pasture-fed free-range hens to conventional birds. For the health benefits of free-range eggs, make sure you purchase them from pasture-fed flocks.
Less Fat and Cholesterol
The American Heart Association recommends reducing intake of both saturated fat and cholesterol in order to reduce your risk of heart disease and stroke (see References 4). Testing by "Mother Earth News" found that eggs from pasture-fed free-range hens, on average, contained one-third of the cholesterol and one-fourth of the saturated fat as conventional eggs (see References 2, page 1). A Sustainable Agriculture Research and Education study yielded similar results, with pastured hens producing eggs with 10 percent less fat and 34 percent less cholesterol (see References 3).
More Vitamin A
Vitamin A promotes the healthy development of teeth, bones, soft tissue and tissues in the eyes needed for good vision; it also acts as an antioxidant and protects cells from damage (see References 5). The "Mother Earth News" and SARE studies found that free-range eggs contained 67 percent and 40 percent more vitamin A, respectively, than conventional eggs (see References 2, pages 1 and 3).
More Vitamin E
Vitamin E also protects cells by acting as an antioxidant, in addition to promoting healthy blood and circulatory system function (see References 6). Free-range eggs contain more vitamin E than their conventional counterparts. The "Mother Earth News" survey found triple the vitamin E in the eggs they tested, and Pennsylvania State University research found double the vitamin E in the eggs of grass-fed hens (see References 2, pages 1 and 7).
Omega-3 Fatty Acids
Omega-3 fatty acids are a form of polyunsaturated fat known as "essential" fatty acids because the body cannot manufacture them on its own; you must consume them from food. Omega-3s are connected to heart health, lowering cholesterol and blood pressure, and other potential health benefits such as decreased risk of diabetes, stroke, digestive disorders, rheumatoid arthritis, some cancers and dementia (see References 8). All three studies found higher amounts of omega-3s in free-range eggs versus conventional eggs. "Mother Earth News" reported the most modest differences, with the free-range eggs they tested containing only twice the omega-3s as conventional eggs, while the Penn State study found 2 1/2 times more (see References 2, pages 1 and 7). Free-range hens in the SARE study, however, produced eggs with four times the omega-3s as their caged sisters (see References 3).