Eggs are celebrated for being a nutritional powerhouse, packed with high-quality protein, essential vitamins, and healthy fats. However, you can maximize their nutritional value through factors such as sourcing, storage, and cooking methods.
The Scare Factor
Right now, egg prices are at a record high. While this is attributed to a bird flu epidemic outbreak, even that is not new. There was an avian epidemic outbreak in 2010 in the USA, after which things calmed down, but it is surging again in recent years following 2022. Experts want to give the birds antibacterials. Humans who have flocks in their yards are now being diagnosed with the bird flu.
There are ways to offset our fears:
- Buy local, organic, pasture-raised eggs
- Preserve eggs longer without sacrificing health benefits
In this article, we’ll explore the best practices for selecting, storing, and preparing eggs to optimize their health benefits.
The Why-Should-I-Care Factor
An eggshell is made of calcium carbonate, which comes mostly from a hen’s bones. Calcium carbonate makes up nine to 12 percent of an egg’s total weight. The shell has seven to 17,000 tiny pores that allow air and moisture to move through. The outermost layer, called the bloom or cuticle, helps keep out dirt and bacteria.
Sourcing High-Quality Eggs
Not all eggs are created equal. The nutritional content of an egg largely depends on the diet and living conditions of the hen that laid it. Here’s how to choose the best eggs:
1. Egg Shell Color
Let’s get this out of the way first.
- White: An interesting fact is that all eggs start out with white shells, no matter the breed of hen. It is rumored that Christopher Columbus brought the first white eggshell to America, all the way from Italy.
- Brown or Brick: When it comes to nutrition and taste, these aren’t any different than white eggs. During the third stage of the egg-laying process, the hen applies a brown pigment to the eggshell. The pigmentation doesn’t pass through the shell though, as the inside of your eggshell stays white.Breed, age and stress levels affect the tone and the depth of color. For example, a young hen might lay darker eggs than a more mature hen. Some breeds lay light-colored eggs that might look pink or rosy, while others develop eggs as dark as chocolate.
- Blue: Unlike brown eggs, the bluish tint appears early in the egg-forming process. Because the pigment reaches the egg during an early stage, it colors the interior of the eggshell blue too!
- Green: The result of crossbreeding genes from blue eggshells with genes from brown eggshells. These festive-colored eggs are green on the outside and blue on the inside. Only a few chicken breeds can produce this colored eggshell, which makes them a rarer find.
Conclusion: The color of an egg shell doesn’t affect its nutritional value. It’s fun to have one color over another, but is probably not worth the cost markup to get the pretty blue and green eggs.
2. Choose Pasture-Raised or Free-Range Eggs
Studies show that pasture-raised eggs contain significantly higher levels of omega-3 fatty acids, vitamin D, and antioxidants such as lutein and zeaxanthin compared to conventionally raised eggs (Karsten et al., 2010). Look for certifications such as “Certified Humane” or “Animal Welfare Approved” to ensure ethical and nutritious choices.
Before we go on, let’s break down the different types of eggs.
- Caged Eggs: About 90% of eggs in the U.S. come from caged hens. The birds are confined to cages for their egg-laying lives and are given 67 square inches each. They eat a corn or soy diet.
- Cage-Free Eggs: These birds have more room than caged hens, as they are each provided with less than 1 square foot. They are confined to the barns and eat a diet of corn or soy.
- Free-Range Eggs: These hens are allotted less than 2 square feet per hen which is more than caged and cage-free hens, but don’t go outdoors too often. They are usually fed a corn or soy based diet.
- Pasture-Raised: Each hen is allotted at least 108 square feet. They eat a combination of carefully balanced supplemental feed and whatever they can find in the dirt when they go outdoors including grass, worms and bugs. They are able to leave the barns early in the morning and are called back before nightfall.
3. Look for Organic or Non-GMO Options
Organic eggs come from hens that are fed organic, non-GMO feed without antibiotics or synthetic pesticides. While this may not dramatically alter the macronutrient profile of the egg, it does reduce exposure to potential toxins (Consumer Reports, 2016).
Let’s first (try to) differentiate Organic and Non-GMO. In short, while both certifications exclude GMOs, they approach this goal from different angles — a targeted approach for the Non-GMO Project and a holistic one for USDA organic. Also, the two programs use distinct tools and methods to accomplish their aims.
- Organic: USDA certified organic is a holistic certification that covers a wide range of food production practices. It sets rules for how animals are raised, how crops are grown, how pests are managed and more. Organic production excludes the use of synthetic pesticides, chemical fertilizers and genetically modified organisms (GMOs).
- Non-GMO Project Verified: A single-issue certification that focuses solely on GMOs. Our definition of GMOs is adapted from an international treaty on biosafety. Working from a clear and comprehensive definition means so-called “new GMOs,” including GMOs made from new genomic techniques, are considered GMOs under the Non-GMO Project Standard. Many of these are entering the market unlabeled and unregulated.
In summary: The Non-GMO Project clearly defines GMOs and requires testing of major, high-risk ingredients. By contrast, organic does not require testing; products must contain 95-100% certified organic ingredients. USDA organic requires organic feed for certified livestock, while Non-GMO Project Verified requires that livestock are non-GMO and their feed is non-GMO or organic. Both certifications must be renewed annually.
The following table compares Non-GMO Project Verified and USDA certified organic and outlines the key similarities and differences between the two.
Confused? Yes. Me, too, How do we determine what to buy? My assessment is that we do the best that we can. Encourage local farmers towards the most holistic methods. Use personal judgement on what is fresh, healthful, and nutrient-rich.
4. Check for Freshness
Eggs lose nutrients over time. Fresher eggs contain higher levels of certain vitamins, such as vitamin E. You can check freshness by placing an egg in a bowl of water—if it sinks, it’s fresh; if it floats, it’s old due to increased air pockets inside the shell.
Storing Eggs for Maximum Nutritional Retention
Proper storage is key to maintaining egg quality and preventing spoilage. Here are some guidelines:
1. Keep Eggs in the Refrigerator
Eggs should be stored at or below 40°F (4°C) to slow bacterial growth and preserve nutrients (FDA, 2021). Refrigeration also helps maintain egg protein integrity and prevents the breakdown of essential amino acids.
If you live in a seasonal climate, you can easily keep your eggs on your balcony, outside, or even in your basement.
2. Store Eggs in Their Original Carton
Egg cartons help prevent moisture loss and protect eggs from absorbing odors and bacteria from other foods in the fridge. Storing them on a shelf rather than the door minimizes temperature fluctuations.
3. Don’t Wash Eggs Until Use
Eggs have a natural protective coating called the bloom, which helps prevent bacterial contamination. Washing eggs removes this coating and can make them more susceptible to spoilage.
Remember that egg shells are themselves porous, so don’t throw them away easily. Use them as seedling starters, as calcium supplements, and as a delivery of nutrients to your soil.
Cooking Eggs to Preserve Nutrients
The way you cook eggs affects their nutritional profile. Here’s how to prepare eggs while retaining their health benefits:
1. Use Low to Medium Heat
Cooking eggs at high temperatures can degrade heat-sensitive nutrients such as vitamin B12 and antioxidants (Hernández-Díaz et al., 2020). Gentle cooking methods like poaching, boiling, or scrambling at low heat help preserve these nutrients.
2. Pair Eggs with Healthy Fats
Adding healthy fats like bacon fat, avocado, or olive oil can enhance the absorption of fat-soluble vitamins (A, D, E, and K) found in eggs (Weaver & Dwyer, 2019). Avoid using processed and seed oils, which can introduce harmful trans fats.
3. Minimize Oxidation of Cholesterol
When eggs are overcooked, the cholesterol in the yolk may oxidize, which can contribute to inflammation (Hu, 1999). Soft-boiled or lightly scrambled eggs help reduce oxidation while maintaining nutritional integrity.
4. Add Vegetables for Synergy
Eggs pair well with nutrient-dense vegetables like spinach, bell peppers, and mushrooms. This combination provides additional fiber, antioxidants, and vitamins that support overall health.
Conclusion
Eggs are an affordable and highly nutritious food, but their health benefits depend on how they are sourced, stored, and prepared. Opt for pasture-raised or organic eggs, store them properly to maintain freshness, and cook them using gentle methods to retain their essential nutrients. By following these practices, you can maximize the health benefits of eggs and enjoy their rich, wholesome goodness in your diet.
References
- FDA. (2021). “Refrigeration and Food Safety.” U.S. Food and Drug Administration.
- Hernández-Díaz, Y., et al. (2020). “Effects of Cooking Methods on Nutrient Retention in Eggs.” Journal of Food Science and Technology.
- Hu, F. B. (1999). “Egg Consumption and Risk of Cardiovascular Disease in the Physicians’ Health Study.” American Journal of Clinical Nutrition.
- Karsten, H. D., et al. (2010). “Pasture-Raised Eggs Have Higher Nutritional Content Compared to Conventional Eggs.” Poultry Science Journal.
- Weaver, C. M., & Dwyer, J. (2019). “Nutrition: Concepts and Controversies.” Cengage Learning.
- Consumer Reports. (2016). “The Truth About Organic Eggs.” Consumer Reports Journal.
https://www.nbcnews.com/select/shopping/how-to-store-eggs-rcna191843?utm_source=firefox-newtab-en-us
https://apnews.com/article/egg-prices-record-bird-flu-a2394bdefc7bd0514d4f003cc5e8a908
https://www.usatoday.com/story/news/nation/2024/06/15/bird-flu-timeline-us/73807511007
