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Eggs: To Eat or Not to Eat? by Christina Badaracco, MPH, RD

Few foods in the modern diet have such a shadow of confusion surrounding them as the egg. Though a rich and versatile source of protein and micronutrients, many people continue to be concerned about their saturated fat and cholesterol content. Navigating the latest nutrition research is indeed complicated. Many consumers are also concerned about the sustainability and animal welfare of egg production, struggling to understand the difference between labels like "antibiotic-free," "cage-free" and "pasture-raised." Can eating eggs be good for people and good for the planet?


How are egg consumption patterns changing?

Despite changing recommendations regarding the consumption of cholesterol—and eggs, in particular—eggs have remained dietary staples. Consumption fell slightly around the middle of the 20th century but is now somewhat stable, around 250 eggs per person per year.

Average per capita egg consumption in the US, based on USDA Economic Research Service loss-adjusted food availability data. https://www.ers.usda.gov/data-products/food-availability-per-capita-data-system/; https://www.ers.usda.gov/publications/pub-details/?pubid=104507


Although chicken eggs are the most common, we also occasionally eat eggs from ducks, geese, quail and even fish (called roe). Varieties like duck eggs may be slightly higher in protein, omega-3 fatty acids and some vitamins, but overall, nutrient content does not vary widely among the different eggs. (Note that fish eggs are much smaller than bird eggs; a 1.5-tablespoon serving contains amounts of most nutrients comparable to those in bird eggs.)


What are the nutritional benefits of eating eggs?

Eggs are beloved as a quick and affordable source of protein. They can be purchased at most stores for low costs and at high-end farmers markets. It's typically possible to buy two organic eggs for less than $0.75, which is half the price of a serving of organic chicken that would provide the same amount of protein. A large batch of boiled eggs can last many days to feed one person, while a large pan of scrambled eggs can easily feed a crowd.


Egg yolks are the most calorie-dense portion of eggs, but they also contain the richest source of micronutrients. Except for patients with genetic lipid disorders, the yolk should typically be consumed along with the white to maximize the nutritional benefits of eggs and minimize waste.


In addition to protein (primarily found in egg whites), eggs are a source of many other essential compounds. Egg yolks are one of our richest dietary sources of vitamin D. Vitamin D plays several important roles in our bodies and it's challenging to obtain sufficient quantities through our diet. Two eggs provide 20% of our Recommended Dietary Allowance. So, when combined with a serving of full-fat dairy, fortified cereal and plenty of sunshine (protected with sunscreen, of course), eggs can provide a significant contribution toward a recommended daily dose of vitamin D in the diet. Egg yolks are also excellent sources of zeaxanthin and lutein, two carotenoids known for their role in promoting eye health by blocking blue light and reducing the risk of advanced age-related macular degeneration.


Finally, eggs are known for providing a rich source of choline. This essential nutrient is involved in many metabolic and neurologic processes (including supporting memory) and is indeed an important part of the diet. You might recall reading this Insight about TMAO, suggesting that choline is one of several nutrients that increase the production of this atherogenic compound. Choline has also been shown to increase homocysteine in the blood; at high concentrations, this promotes inflammation and dyslipidemia (or elevated blood lipids). However, prospective studies have typically failed to find a significant relationship between choline intake and cardiovascular disease outcomes. Most experts believe that moderate consumption is indeed safe—and even beneficial.

Nutrients found in egg white and yolk. Data source: https://fdc.nal.usda.gov/


How have recommendations about egg consumption changed?

Until the last decade, health professionals and nutrition researchers typically recommended limiting egg consumption to avoid excess cholesterol. Since each large egg contains more than 180 mg of cholesterol, two eggs provide more than the daily limit of 300 mg previously recommended in the Dietary Guidelines for Americans. However, as we have learned that dietary cholesterol is not closely linked with serum cholesterol (except for in people with genetic lipid disorders and possibly those with diabetes), most researchers now believe eggs should no longer be limited solely due to their cholesterol content. Indeed, according to 2013 and 2020 meta-analyses, moderate egg consumption is not associated with an increased risk of heart disease. It has been suggested that some of the fats called phospholipids found in eggs have a somewhat protective effect against elevating blood cholesterol.


A 2019 prospective cohort study in JAMA found the opposite: among U.S. adults, higher consumption of cholesterol or eggs was associated with an increased risk of heart disease and death. The relationship followed a dose-response pattern, meaning higher consumption was associated with a greater risk. A 2022 systematic review and updated meta-analysis also showed that greater dietary cholesterol and egg consumption were associated with increased risk of overall heart disease-related mortality. However, the increased risk was measured based on increments of 1 egg or 300 mg per day, which exceeds the average daily intake of eggs and total cholesterol. Therefore, the findings may not apply to Americans consuming less than this amount.


Given the heterogeneity in these findings, recommendations about eating eggs in low to moderate amounts are therefore not likely to change in the near future, but it is important to be aware—as in all areas of nutrition research—that we very rarely know when we reach a sound conclusion. Indeed, a subsequent umbrella review of meta-analyses looking at egg consumption and human health in August 2019 found no association with adverse health outcomes.


What are the healthiest ways to eat eggs?

Cooking eggs has been shown to increase their protein availability. It also kills bacteria and makes them safe to eat. Since they contain plenty of fat already, they need only be cooked in enough oil to prevent sticking if fried or scrambled. As with many other foods, cooking destroys some micronutrients and other beneficial compounds, such as carotenoids.

  • Overall, boiling seems to lead to less degradation than higher-heat methods like frying and scrambling. Since eggs cooked in water can only reach 212 degrees F, boiling and poaching may be the healthiest ways to eat them.

  • Baked eggs have been shown to contain less vitamin D, which we already have a hard time getting in our diets.

  • Finally, higher-heat cooking causes the cholesterol in eggs to oxidize, meaning they are more atherogenic and stronger contributors to heart disease.

  • Keep in mind that ingredients added to eggs can also support the health benefits of your meal; cooking with extra virgin olive oil and/or adding spices will introduce various beneficial compounds, for example.

What are some alternatives to eggs?

People may want to find alternatives to eggs to reduce their environmental impact, ensure animal ethical treatment or for other reasons. Other plant-based sources of protein, such as nuts, seeds, legumes and fermented soy products, can be good substitutes (although they don't provide the same micronutrients). Because of their fiber content, ground flax and chia can serve as good binders for those interested in replacing eggs in baked goods. They also contain healthy omega-3 fatty acids and some protein. Aquafaba, which is the liquid in chickpea cans, can be whipped to serve as a leavening agent in baked goods and meringue. This article on egg substitutes offers various alternatives that can be incorporated into different recipes.


Following the increasing availability of plant-based meat and dairy products on the market, various brands selling plant-based eggs in different forms have come to market in recent years. The most common versions are made of mung bean isolates and processed oil or soymilk powder and cellulose, though some newer versions have more wholesome ingredients like organic tofu or nuts. Note that most of these products are lower in almost all micronutrients than real eggs; some are also lower in protein.


What are the best ways to incorporate eggs into my diet?

  • Choose eggs from pasture-raised hens, if available. These hens can roam outside and have a more nutritious diet, meaning their eggs are also more abundant in nutrients (such as vitamins A and E, omega-3 fatty acids and more). Choosing organic eggs helps to ensure the feed was free of GMOs and antibiotics. The "hormone-free" label on eggs doesn't mean anything, since chickens are never fed hormones to promote growth. If possible, buy your eggs from a farmers market to ensure the farmer earns a decent profit and can vouch for his/her production practices.

  • Two eggs provide 14 grams of protein, which is ample for a meal when incorporated with other components. Restaurants often serve omelets with much more egg than this, so they can be shared or provide plenty for leftovers.

  • The latest evidence suggests it is probably fine to eat eggs a few times a week, but most people should probably not eat them in large quantities or every day.

If you choose to avoid eggs (or animal products in general), plant-based sources can provide ample protein and fat. Just ensure you are getting enough vitamin A, vitamin D and other micronutrients from other sources and read the ingredient list to avoid those you don't recognize.



Resources

The full list of resources can be found here.


Christina Badaracco, MPH, RD

Christina is a registered dietitian and author who aims to improve access to healthy and sustainable food and educate Americans about the connections between food and health. She loves to experiment with healthy recipes in the kitchen and share her creations to inspire others to cook.


Christina completed her dietetic internship at Massachusetts General Hospital and earned her Master of Public Health degree from the University of California, Berkeley. Previously, she graduated with a degree in Ecology and Evolutionary Biology from Princeton University, after conducting her thesis on sustainable agriculture and energy in Kenya. She has done clinical nutrition research at the National Institutes of Health, menu planning and nutrition education at the Oakland Unified School District and communications at the Environmental Protection Agency's Office of Water. She has also enjoyed contributing to children’s gardens, farmers markets and a number of organic farms.


cbadarac@gmail.com

www.linkedin.com/in/christina-badaracco/

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