The nutritional value of free-range versus cage-produced shell eggs has been a source of ongoing controversy in recent years. Many websites and other publications have touted the health benefits of eggs from free-range birds. However, the fact of the matter is that little scientific evidence exists to support this assertion. And a recent publication by Dr. Ken Anderson from North Carolina State University (Poultry Science 90:1600-1608, 2011) bears this out. Dr. Anderson looked at the fat, cholesterol, and vitamin content of eggs from free-range birds versus conventional cage birds. And his data indicated no difference in the cholesterol content of the eggs (163 mg per large egg for the caged birds; 165 mg per large egg for free-range birds). Similarly, the vitamin A and E content of the eggs were not affected by the conditions to which the birds were exposed. In fact, the total fat content of the free-range birds’ eggs was actually higher than that of the caged birds (the authors hypothesized that this may have been due to the relatively high-fat insects that the free-range hens had access to). A recent study in Europe (Hidalgo et al., Food Chem 106:1031-1038, 2008) demonstrated similar results (free-range eggs no better than caged hen eggs).
No doubt that this debate will continue, largely because it is so tinged with emotion. But science, well done, is free of emotion. And current science doesn’t support the notion that the manner in which laying hens are raised can impact the nutritional quality of the eggs they produce. In fact, raising birds in a more controlled environment offers the ability to better control the diet, thus raising the potential for creating even more healthy egg products in the future.
To read more, please see the press release the Poultry Science Association put out with Ken Anderson. http://www.poultryscience.org/pr081511.asp?autotry=true&ULnotkn=true