Sainsbury's decision to phase out brown eggs in favour of white ones has sparked public debate over whether there is any nutritional difference between the two. The supermarket chain claims white eggs have a 12.7% lower carbon footprint, as hens laying white eggs require less feed to produce the same quantity of eggs.
Feed production accounts for 50-60% of the environmental impact of egg farming. With the UK consuming approximately 14.5 billion eggs annually, a nationwide shift to white eggs could reduce CO2 emissions by over 550,000 tonnes per year—equivalent to taking nearly 300,000 cars off the road.
Despite the common belief that brown eggs are superior, experts say there is no nutritional distinction. The colour of the shell depends solely on the breed of hen: white hens lay white eggs, brown hens lay brown eggs. Yolk colour, often associated with quality, is influenced by diet—particularly feed containing marigold or paprika—not nutritional value.
Consumers are advised to check the egg stamp code for farming method: 0 for organic, 1 for free-range, 2 for barn, and 3 for caged (though major supermarkets no longer sell caged eggs). Neither shell nor yolk colour indicates hen health or egg quality.
