Eggs are a cheap but incredibly nutritious food.
They contain relatively few calories, but they’re packed with proteins, vitamins, minerals, healthy fats and various trace nutrients.
That said, the way you prepare your eggs can affect their nutrient profile.
This article explores the healthiest ways to cook and eat eggs.
A Review of the Different Cooking Methods
Eggs are delicious and extremely versatile.
They can be cooked in many different ways and are easy to combine with other healthy foods, like vegetables.
Cooking them also destroys any dangerous bacteria, making them safer to eat.
Here’s a breakdown of the most popular cooking methods:
Hard-boiled eggs are cooked in their shells in a pot of boiling water for 6–10 minutes, depending on how well cooked you want the yolk to be.
The longer you cook them, the firmer the yolk will become.
Poached eggs are cooked in slightly cooler water.
They are cracked into a pot of simmering water between 160–180°F (71–82°C) and cooked for 2.5–3 minutes.
Fried eggs are cracked into a hot pan that contains a thin layer of cooking fat.
You can then cook them “sunny side up,” which means the egg is fried on one side, or “over easy,” which means the egg is fried on both sides.
Baked eggs are cooked in a hot oven in a flat-bottomed dish until the egg is set.
Scrambled eggs are beaten in a bowl, poured into a hot pan and stirred over low heat until they set.
To make an omelet, eggs are beaten, poured into a hot pan, and cooked slowly over low heat until they’re solid.
Unlike scrambled eggs, an omelet is not stirred once it’s in the pan.
Microwaves can be used to cook eggs in many different ways. It takes much less time to cook eggs in a microwave than it does on a stove.
However, it’s usually not a good idea to microwave eggs that are still inside their shells. This is because pressure can quickly build-up inside them, and they may explode (1, 2).
Bottom Line: Eggs can be cooked in many different ways, including boiling, poaching, frying, baking and scrambling.
Cooking Makes Some Nutrients More Digestible
Cooking eggs makes them safer to eat, and it also makes some of their nutrients easier to digest.
One example of this is the protein in eggs.
Studies have shown it becomes more digestible when it’s heated (3).
In fact, one study found that the human body could use 91% of the protein in cooked eggs, compared to only 51% in raw eggs (4).
This change in digestibility is thought to occur because heat causes structural changes in the egg proteins.
In raw eggs, the large protein compounds are separate from each other and curled up in complex, twisted structures.
When the proteins are cooked, heat breaks the weak bonds that hold them in shape.
The proteins then form new bonds with the other proteins around them. These new bonds in the cooked egg are easier for your body to digest.
You can see these changes occurring as the egg white and yolk change from a thick gel to rubbery and firm.
The protein in raw eggs can also interfere with the availability of the micronutrient biotin.
Eggs are a good source of biotin, which is an important nutrient used in fat and sugar metabolism. It’s also known as vitamin B7, or vitamin H.
In raw eggs, a protein in the egg whites called avidin binds to biotin, making it unavailable for your body to use.
However, when eggs are cooked, the heat causes structural changes to avidin, making it less effective at binding to biotin. This makes biotin easier to absorb (5).
Bottom Line: Cooking eggs makes the protein in them more digestible. It also helps make the vitamin biotin more available for your body to use.
High-Heat Cooking May Damage Other Nutrients
Although cooking eggs makes some nutrients more digestible, it can damage others.
This isn’t unusual. Cooking most foods will result in a reduction of some nutrients, particularly if they are cooked at high temperatures for a long period of time.
Studies have examined this phenomenon in eggs.
One study found that cooking eggs reduced their vitamin A content by around 17-20% (6).
Cooking may also significantly reduce the amount of antioxidants in eggs (7, 8, 9).
One study found that common cooking methods, including microwaving, boiling and frying eggs, reduced the amount of certain antioxidants by 6–18% (10).
Overall, shorter cooking times (even at high temperatures) have been shown to retain more nutrients.
Research has shown that when eggs are baked for 40 minutes, they may lose up to 61% of their vitamin D, compared to up to 18% when they’re fried or boiled for a shorter period of time (11).
However, even though cooking eggs reduces these nutrients, eggs are still a very rich source of vitamins and antioxidants (5).
Bottom Line: Cooking eggs can reduce their vitamin and antioxidant content. However, they are still very high in nutrients.
High-Heat Cooking Oxidizes the Cholesterol in Eggs
Egg yolks are high in cholesterol.
In fact, one large egg contains about 212 mg of cholesterol, which is 71% of the previously recommended intake of 300 mg per day (12).
There is now no recommended upper limit on daily cholesterol intake in the US.
However, when eggs are cooked at high temperatures, the cholesterol in them may become oxidized and produce compounds known as oxysterols (13, 14).
This is a concern for some people, as oxidized cholesterol and oxysterols in the blood have been linked to an increased risk of heart disease (15, 16).
Foods containing oxidized cholesterol and oxysterols are thought to contribute to the blood levels of these compounds (17).
That being said, the main dietary sources of oxidized cholesterol aren’t eggs. They are commercially fried foods such as fried chicken, fish and French fries (18).
It’s also worth noting that cholesterol that is oxidized in the body is thought to be more harmful than the oxidized cholesterol that you eat (15).
Most importantly, studies haven’t shown a link between eating eggs and an increased risk of heart disease in healthy people (19, 20, 21, 22, 23, 24).
Bottom Line: High-heat cooking can oxidize the cholesterol in eggs. However, eating eggs has not been linked with an increased risk of heart disease in healthy people.
5 Tips to Cook Super Healthy Eggs
Eggs are nutritious, but you can make your eggs even healthier.
Here are five tips to cook super healthy eggs:
1. Choose a Low-Calorie Cooking Method
If you are trying to cut back on calories, choose poached or boiled eggs.
These cooking methods don’t add any extra fat calories, so the meal will be lower in calories than fried or scrambled eggs or an omelet.
2. Combine Them With Vegetables
Eggs go really well with vegetables.
This means that eating eggs is a great opportunity to boost your vegetable intake and add extra fiber and vitamins to your meal.
Some simple ideas include adding the vegetables of your choice into an omelet or scrambled eggs, like in this recipe.
Or simply cook the eggs whichever way you want and have vegetables on the side.
3. Fry Them in an Oil That’s Stable at High Temperatures
The best oils for cooking at high heat, like when pan frying, are those that remain stable at high temperatures and don’t oxidize easily to form harmful free radicals.
Examples of good choices include extra virgin olive oil and butter. Coconut oil is also a good choice for high-heat cooking, but some people may not like the taste with eggs.
4. Choose the Most Nutritious Eggs You Can Afford
The nutritional quality of eggs can be influenced by a number of factors, including the farming method and chicken’s diet (25).
In general, pasture-raised and organic eggs are thought to be nutritionally superior to caged and conventionally-produced eggs.
This article goes into detail about the nutritional differences between eggs produced by different methods.
5. Don’t Overcook Them
The longer and hotter you cook your eggs, the more nutrients you may lose.
Using higher heat for longer may also increase the amount of oxidized cholesterol they contain. This is particularly true of pan frying.
Bottom Line: To make your eggs as healthy as possible, choose a low-calorie cooking method, combine them with vegetables, fry them in a heat-stable oil and don’t overcook them.
Take Home Message
Overall, shorter and lower-heat cooking methods cause less oxidation of cholesterol and help retain most of the nutrients in the eggs.
For this reason, poached and boiled (either hard or soft) eggs may be the healthiest to eat. These cooking methods also don’t add any unnecessary calories.
All that being said, eating eggs is generally super healthy no matter which way you cook them.
So you may just want to cook and eat them in the way you enjoy the most and not obsess over the small details.