Because eggs are nutrient dense and are a relatively cheap protein source, they are a common food staple for many households around the world.
An egg provides 6 grams of protein, about 75 calories, all essential amino acids, zero grams of carbohydrate, vitamin D, B vitamins, selenium and choline.
Eggs are a rare natural source of vitamin D and selenium. These two nutrients can be challenging to get enough of in the diet.
Even though eggs provide a source for many vitamins and minerals, they are also notoriously high in cholesterol.
The good news is eggs are no longer a taboo food because of their higher cholesterol levels.
Recent research has suggested eating up to one egg per day does not increase risk for heart disease. A 2017 review (1) also suggests eating up to 12 eggs per week does not increase risk for cardiovascular disease for most people.
What can impact the nutrient levels in eggs is the diet and health of the hen.
What may be surprising is the color of the egg shell doesn’t affect nutrition values. Therefore, brown eggs are not healthier than white eggs.
Why eggs are different colors
In the Unites States, most eggs are white. Brown eggs are also an option in most supermarkets and at farmers markets.
However, brown eggs are typically more expensive than white eggs. Just because brown eggs are more expensive doesn’t mean they are healthier than white eggs.
Brown eggs can be more expensive than white eggs because the hens that lay brown eggs usually eat more.
Eggs can actually be many different shades of colors, not just brown or white. What makes chicken eggs different colors is the type of hen that laid the egg, and more specifically the color of their ear lobes.
Any differences in egg shell thickness are not related to the color of the egg. Egg shell thickness is related to the age of the chicken.
No matter the color, younger hens tend to lay eggs with thicker shells (3).
Are brown eggs healthier?
Some people argue brown eggs actually taste different than white eggs.
This may be true, but it is not because of the different shell color. Brown eggs are not necessarily healthier or taste better than white eggs.
What may be due to a difference between white or brown eggs could be more what the difference is between what the chickens are eating.
Hens that lay brown eggs are more likely to be from backyards or smaller farms.
The reason these eggs may taste different isn’t because of the shell, it’s because they may have a different diet than chickens that lay eggs you eat from the grocery store.
What is the chicken eating?
What the chicken eats can impact the taste and nutrition of an egg. The amount of omega 3 fatty acids in eggs is directly associated with the chicken’s diet.
A 2003 study (4) found when white and brown hens ate a diet of 10% flaxseed, the omega 3 levels in eggs were significantly higher compared to chickens not receiving the flaxseed.
Most conventional eggs available in grocery stores are from hens in larger farms fed a diet mostly of corn or other grains.
However, free range eggs or pastured hens have access to eating a more varied diet.
While most people assume free range or pastured hens produce healthier eggs, this isn’t always the case.
If the hens are pecking on land that has pesticides or other harmful contaminants sprayed, those contaminants can go from the chicken into the eggs.
According to 2010 TIME article (5), free range eggs from the US and the EU have been shown to have higher levels of PCBs compared to eggs in factory farms.
PCBs are found in the environment and are a bi-product from manufacturing processes.
Using PCB’s have been banned for years, but because it breaks down very slowly PCBs are still in the environment. Exposure to PCBs can be harmful and may increase risk for various health problems (6).
A Brazilian study also found certain free range eggs to have higher levels of the potent pesticide DDT because that had been used on the land years ago.
Even though it wasn’t recent, DDT is slow to degrade and can stay in the ground for a long time.
Organic, free range of pastured eggs?
Currently, the options for choosing eggs are many. You can buy white, brown, conventionally raised, pastured, free range, organic, farm raised, etc. eggs.
How do you know which one is best? There are many factors that can go into picking your eggs from the health of the chicken to the nutritional value of the egg.
There are many opinions and studies suggesting pros and cons of all growing and feeding practices of egg laying hens.
Some studies show there really isn’t a significant difference between how the hen is raised and the nutrition of the egg (7).
A 2014 Washington Post article (8) also suggests there aren’t significant differences between conventional and organic eggs.
Scientists from Auburn University suggest egg laying hens aren’t routinely given antibiotics, and egg samples haven’t show residues of drugs or antibiotics in eggs.
Some of the phrases used for raising chickens is not well regulated. For example, cage free eggs may or may not mean the chickens are running around outside.
It may just mean they are still in a large barn with other chickens, but there is a door open somewhere.
Conclusion
The color of the egg shell does not impact nutritional value of the egg.
Brown eggs offer the same nutritional value as white eggs. What can impact the nutrition of eggs is the diet and health of the hen.
There are many varying opinions and research about the different methods of raising egg laying hens.
Some studies have shown factory farm eggs are not significantly different nutritionally compared to organic eggs.
Free range chickens may have a more varied diet, but they can also have access to land that may be contaminated with pesticides which can be passed to the eggs.
