At grocery stores across the country, brown eggs command a premium price over white eggs from the same display case. Consumers select them with the understanding that brown equals more natural, more nutritious, more wholesome — somehow closer to what a real egg should be. The white ones seem factory, clinical. The brown ones seem farmyard.

Excerpted from “You’re Doing It Wrong”

The shell color has nothing to do with nutritional content. It has everything to do with the breed of chicken.

White-feathered breeds with white earlobes — primarily Leghorns — lay white eggs. Red or brown-feathered breeds — Rhode Island Reds, Plymouth Rocks, and others — lay brown eggs. The earlobe is actually a reasonably reliable predictor of shell color: white earlobes, white eggs; red earlobes, brown eggs. Some breeds lay blue, green, or speckled eggs. The color is genetic, a function of pigment deposition during egg formation in the oviduct. It has no bearing on what is inside the egg.

Nutritional analyses of brown and white eggs from comparable housing conditions and diets find no meaningful differences in protein content, fat composition, vitamin levels, or mineral content. The egg inside is the same egg.

What does affect egg nutrition is the diet and environment of the hen. Eggs from hens with access to pasture and diverse forage — grass, insects, seeds — tend to have higher omega-3 fatty acid content, more vitamin D, and higher levels of certain antioxidants compared to eggs from hens on a grain-only diet in confined housing. This is a function of what the hen ate, not what color she laid.

The relevant distinction is not shell color. It is housing and diet: pasture-raised, free-range, and omega-3 enriched labels reflect conditions that can affect the egg’s nutritional profile. Shell color reflects nothing but breed.