Sunday, October 31, 2010
The nutritional benefits of eggs
In 1974, the British Journal of Nutrition found that pastured eggs had 50 percent more folic acid and 70 percent more vitamin B12 than eggs from factory farm hens.
In 1988, Artemis Simopoulos, co-author of The Omega Diet, found pastured eggs in Greece contained 13 times more Omega 3 polyunsaturated fatty acids than U.S. commercial eggs. A 1998 study in Animal Feed Science and Technology found that pastured eggs had higher Omega 3 and vitamin E than eggs from caged hens.
A 1999 study by Barb Gorski at Pennsylvania State University found that eggs from pastured birds had 10 percent less fat, 34 percent less cholesterol, 40 percent more vitamin A, and four times the Omega 3 compared to the standard USDA data.
In 2003, Heather Karsten at Pennsylvania State University found that pastured eggs had three times more Omega 3, 220 percent more vitamin E and 62 percent more vitamin A than eggs from caged hens.
In 2007, the US magazine Mother Earth News analysed eggs from 14 free range flocks and compared the results to nutritional data available from the U.S. Department of Agriculture (USDA) for commercial eggs, the kind found in most supermarkets.
The free range eggs had:
- 1⁄3 less cholesterol
- 1⁄4 less saturated fat
- 2⁄3 more vitamin A
- 2 times more Omega 3 fatty acids
- 3 times more vitamin E
- 7 times more beta carotene
But be careful when buying 'free-range' eggs. As long as hens have 'access to an outdoor run' producers are able call their eggs free-range. What this usually means is that there is a small opening where hens could go outside, regardless of whether or not they ever do. In most cases a better description would be 'non-cage eggs'.
Often you can visibly tell the difference, but yolk colour is not always a good guide. Pastured yolks are a rich orange color from the beta-carotene in the plants (as long as there is plenty of green feed in the paddocks). Eggs from a genuine free range farm will vary in yolk colour – depending on the time of year and the amount of green feed available. If the yolk colour is always the same, you can be sure that colouring additives are included in the hens' feed.
It's up to you as the consumer to find out how the chickens are being raised and what they're being fed. One way is to look for the logo of the Free Range Farmers Association which gives you a guarantee that the hens are not de-beaked and that the farm meets hen welfare and strict stocking density requirements. Talk to producers at farmers' markets and find out how they manage their flocks and make sure you are comfortable with the way your eggs are produced.