Eggs are an amazing food for many reasons. They're also controversial.
They're a nutritional powerhouse and can even be considered a superfood.
But, many people avoid them entirely (or just eat the egg whites). That happens because eggs are thought to raise cholesterol and increase heart disease risk.
So, which of the two is true and how many eggs a day should you be eating?
The Advantages of Eggs
To say that eggs have advantages is an understatement. Eggs make a powerful addition to the diet - for a variety of reasons.
- They're nutritious. Eggs (particularly the yolks) are nutrient-dense, containing vitamin A, selenium, vitamin B12, choline, vitamin B2, and vitamin B5. There are also smaller quantities of many other nutrients.
- They're a good source of protein. Eggs are a simple way to get more protein into your diet. This also makes them satisfying and effective for weight loss.
- They're versatile. Eggs can be included in many different diet approaches, including keto, paleo and more. There are also countless recipes that include eggs. Many of those are simple, just taking a few minutes to prepare. This aspect is particularly powerful if you're using eggs as a source of protein.
- They're practical. Eggs have a fairly long shelf life and they're often inexpensive. This can sometimes make them more attractive than other sources of protein.
Why Are Eggs So Healthy?
The advantages of eggs aren't just practical. There are also many health benefits to consider.
- The protein in eggs helps promote many outcomes, such as promoting muscle development (1), muscle performance (2,3), weight loss (4,5) and improving bone health (6,7).
- The protein is animal-based, which may offer additional health benefits and includes vitamin B12.
- They're a source of choline, which is associated with brain health and many people are deficient in. The site Nootriment offers an interesting discussion about the implications of choline for the brain.
- They help you to feel satisfied and reduce cravings between meals. This is effective for weight loss and for health.
- They contain antioxidants that can help promote various health benefits, including decreasing the risk of eye diseases (8,9).
What About Eggs and Cholesterol?
Thus far, eggs sound amazing. So, what about the horror stories that link eggs to high cholesterol and heart disease?
First off - eggs are high in cholesterol. A large egg contains around 211 mg of cholesterol. That's 70% of your recommended daily intake. But... the cholesterol content of food doesn't mean all that much.
Cholesterol is a compound that our bodies create and regulate.
This happens because cholesterol is essential. It plays a key role in many biological functions and in creating critical hormones, such as testosterone.
Cholesterol and Heart Disease
Additionally, the relationship between cholesterol and heart disease isn't as clear-cut as you might expect. We've been told to cut down on cholesterol for decades, yet heart disease continues to increase in prevalence (14).
Studies even show that decreasing dietary cholesterol or fat doesn't change heart disease risk (15,16). Likewise, one study showed that close to 75% of heart attack patients had low levels of LDL cholesterol (17).
There are also gaps in our knowledge of heart disease.
Heart disease involves the formation of plaques in arteries, which limits the passage of blood. Over time, these plaques can block the artery entirely. Cholesterol is involved in these plaques - but it doesn't necessarily cause them (18).
That's partly why cholesterol is considered a risk factor. It may increase heart disease risk. But, it may not.
Recent Research on Egg Consumption
So then, theory suggests that eggs don't negatively impact cholesterol or heart disease risk. This perspective isn't just theory either. There is plenty of evidence that highlights how eggs can be good for your health.
Missimer et al, 2017
In this study, the authors compared eating two eggs every day to a traditional 'heart-healthy' breakfast of oatmeal.
- Eating eggs resulted in increases to HDL and LDL cholesterol, but no differences to the ratio between the two. The ratio between HDL and LDL is typically considered a more significant risk factor than simply LDL levels.
- Other heart disease risk factors, like plasma glucose levels, liver enzymes and triglycerides were not affected.
- Egg consumption also increased levels of satiety among participants and was associated with lower levels of the plasma ghrelin.
The authors concluded that there was no difference in heart disease risk between the two types of breakfast.
DiMarco et al., 2017
This study looked at outcomes from participants consuming 0, 1, 2 or 3 eggs per day over a 4-week period.
- The number of eggs per day did not affect BMI, plasma glucose, waist circumference or systolic blood pressure.
- Diastolic blood pressure decreased as egg consumption increased.
- Eating at least 1 egg per day increased HDL cholesterol levels and decreased LDL cholesterol.
- Plasma choline levels increased with egg intake.
Overall, the study found that healthy individuals could consume up to 3 eggs a day. Doing so even had desirable impacts on heart disease risk factors.
Shin et al., 2017
This study was slightly different, as the authors focused on metabolic syndrome among Korean adults. The outcomes are still relevant, especially as the study involved 130,420 participants.
- Consumption of more than 7 eggs per week was linked to decreased metabolic syndrome risk compared to those eating less than 1 egg per week (in women only).
- Higher levels of egg intake were linked to decreased metabolic syndrome components. This included reducing the risk of low HDL.
The outcomes offer additional confirmation that regular egg consumption offers health benefits.
Njike et al., 2016
The authors of this study looked at the health implications of eggs in a diet for adults with type 2 diabetes. As part of the study, participants consumed either 2 eggs per day or no eggs.
- Eating 2 eggs per day didn't significantly affect blood pressure or glycemic control.
- However, eggs did contribute to weight loss, a decrease in weight circumference and in percentage body fat.
Virtanen et al., 2016
This study looked at the connection between cholesterol and coronary artery disease.
The study involved 1,032 men, who ranged from 42 to 60 years old at the beginning of data collection (which was 1984 to 1989). 846 of these men were ultimately included in the study.
The participants were then followed for an average of just over 20 years - which is impressive for any study.
- During this time, 230 incidents of coronary artery disease occurred.
- Across the study, the average egg intake was around 4 medium-sized eggs per week. This accounted for 27.7% of the total intake of cholesterol for participants.
- Out of the study population, 15% of individuals ate at least 1 egg per day.
- Participants with higher levels of egg intake were more likely to be physically active and less likely to have diabetes or to smoke.
Overall, the authors did not find any association between egg consumption or cholesterol intake in general, and coronary artery disease.
This was true in the study population in general and also in the people who had the ApoE4 phenotype. So, even in the most susceptible individuals, there was no relationship between egg consumption and the risk of coronary artery disease.
This strongly reinforces the concept that dietary cholesterol doesn’t have much impact on heart disease at all.
Other Evidence for Eggs
The five studies highlighted previously are just a small selection of recent research into eggs and health. There have been many other studies over the years. Some show significant health benefits from eggs, while other studies show that egg consumption is safe and may even promote health in some areas.
- For example, one study showed that consuming more than 3 eggs per week was associated with a decreased risk of metabolic syndrome (24).
- Another study showed that consuming 2 eggs per day didn’t have a negative effect on lipid profiles for people who were overweight or obese and had either type 2 diabetes or prediabetes (25).
- Eating whole eggs regularly can also improve insulin resistance and lipoprotein profiles in people with metabolic syndrome (26).
Can You Eat Too Many Eggs?
Eggs are nutritious, energy-dense, with the ability to promote health and weight loss. You can even eat multiple eggs every day without adverse effects. But, can you eat too many?
The simple answer is yes - you can eat too much of pretty much anything.
In the case of eggs, the issue isn't really associated with cholesterol or heart disease. Instead, you need to be careful about how eggs fit into the rest of your diet.
- Eggs are energy dense and taste great. Those are both good things. Still, they do mean that you might consume too many eggs and end up gaining weight.
- Likewise, if you add additional eggs to your diet without making any other changes, you might do more harm than good.
- You also need to pay attention to how you have your eggs. For example, three eggs a day can be healthy. But, if you're making scrambled eggs with a large amount of cheese, you might be increasing your calories more than you mean to.
Still, as plenty of people have shown, you can consume many eggs per day if you plan your diet well. For example, some bodybuilders will consume 6 or more eggs per day. Keto dieters will often rely on eggs as well. There are even some diets that specifically focus on eggs.
How Many Eggs Should You Be Eating?
Studies have indicated a range of healthy levels of egg intake including 3 eggs per week (27) all the way up to 3 eggs per day (28). This suggests that even a fairly high amount of eggs isn’t going to have any negative effect.
It's possible that higher amounts of eggs are healthy too. But, the research hasn't been done.
- If you want to be cautious, it may be worth sticking to three a day.
- Plenty of people consume more regularly without harming their health (like Kris from Authority Nutrition). If you choose to, it's worth paying attention to how your body responds over time.
Eggs are also a pretty good choice for food, especially in the morning. After all, they tend to be filling and can be a good way of giving you long-lasting energy. Besides, there is no shortage of ways to prepare them - like this list of egg breakfast recipes from Serious Eats.
The best number is going to depend on your own diet and needs. Some people will find 2 eggs per day more than enough. Others may want more than that. But, whatever you choose, make sure your egg consumption fits into your overall diet and lifestyle.
Want to Improve Your Health?
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What about you? Are you a fan of eggs or do you avoid them?