According to a recent USDA study of organic versus factory eggs reported in Time Magazine, the eggs are indistinguishable in terms of fat and protein content.
There is no question the chickens prefer the free-range life to that of a factory hen, virtually immobilized in a small cage all of her life. But the point of the study was whether a happy hen in fact produces a better product.
The study, "Physical quality and composition of retail shell eggs," published in the March 2010 issue of the journal Poultry Science, used different kinds of eggs – some traditional, others cage-free, free-roaming, pasteurized, omega-3 enhanced, fertile and organic – from Georgia grocery stores. Food technologist Deana Jones and her team found that on average, the eggs were of similar quality with respect to fat and protein content.
They used the Haugh unit – a highly specialized egg-quality metric developed in 1937. The white of an egg is where all its protein is found; it's made of both thin albumen – the watery fluid that runs farthest from the yolk when the egg is cracked into a cold pan – and thick albumen, the more viscous fluid that stays closer to the middle. The greater the amount of thick albumen, the more nutritious the egg.
"The Haugh unit factors together the weight of the egg and the thickness of the albumen layer at the center," says Jones. And that number, she found in her study, is not affected by how a hen is raised. "We found no meaningful differences at all," she says. "We sampled eggs from a number of stores and kept getting the same results over and over. For shoppers, the decision comes down to your ethical and moral choices."
The group "Beyond Pesticides" says the study missed the point. It failed to examine pesticide residues and vitamin content. Nor did it consider the environmental and health impacts of conventional, chemical-based production systems. The study did not examine other nutritional factors that farmers using organic methods often claim to be higher in organic eggs, such as vitamins A and E, beta carotene, folate, omega-3 fatty acids.
The group points out that organic poultry and egg production also prohibits the prophylactic use of antibiotics and arsenic in chicken feed, as well as requiring outdoor access and organically produced chicken feed. Chemically-treated grains in conventional chicken feed can cause environmental damage in the form of water contamination and wildlife poisoning and can be hazardous to those who work on or live near farms.
Dr. Grout's Comment:
I could stick a thermometer under your tongue, see that it is 98.6, and declare you fit as a fiddle. That, like the Haugh unit, is a grossly simplistic measurement. Most of an egg's nutrition is in the yolk that contains fat plus most of the vitamins and minerals of the egg. In 1937 when the Haugh unit was devised, we did not even realize most vitamins existed. And what about the arsenic in conventional feed? This study, although it got a lot of attention in a major magazine, is seriously flawed.
Too bad Time Magazine didn't get curious about the other side of the story and contact an organic group to see what they had to say about eggs from pastured chickens. This study was commissioned by the USDA which, like the FDA, is perhaps more than somewhat beholden to the conventional food manufacturers. A study like this tends to preserve the market share of the average conventional egg producers if it can convince you that organic food isn't worth the extra effort, and that there is no need to support humane agriculture. Judging by many of the comments people posted to the Time Magazine story, they weren't buying the validity of this study either.