What Is Unhealthy About Eggs? A Balanced Look at the Concerns

December 30, 2025 •

5 min read

For decades, eggs were feared for their high cholesterol content, a concern that has since been largely debunked for most healthy individuals. However, this shift in perception doesn't mean eggs are without potential downsides, especially when considering individual health factors, food safety, and cooking methods.

Quick Summary

Eggs have potential downsides related to cholesterol for at-risk individuals, saturated fat content, bacterial contamination risks, and allergies. The health impact depends heavily on an individual's health status and how they are prepared, debunking some long-standing myths.

Key Points

High Cholesterol Impact: For most healthy people, the dietary cholesterol in eggs has minimal impact on blood cholesterol, but those with heart disease or diabetes should be cautious.
Saturated Fat from Cooking: The saturated fat content in an egg is low, but the total saturated fat of an egg-based meal can increase significantly depending on cooking methods and added ingredients like butter and bacon.
Salmonella Risk: Raw or undercooked eggs can be contaminated with Salmonella, posing a food safety risk. This can be prevented by proper refrigeration, handling, and cooking.
Allergy Concerns: Eggs are a common allergen, especially for children. Symptoms can range from mild rashes to severe anaphylaxis, and avoidance is critical for those with an allergy.
Choline and TMAO Debate: Choline in egg yolks is linked to TMAO production by gut bacteria, a compound associated with cardiovascular disease risk, although the clinical significance remains debated.
Moderation is Key: Consuming eggs in moderation as part of a balanced diet is generally healthy, with the potential downsides heavily dependent on individual health and preparation methods.

Re-evaluating the Cholesterol Concern

For years, a central argument against eggs centered on their high dietary cholesterol content, leading to broad recommendations to limit intake. A single large egg contains about 186 mg of cholesterol, all concentrated in the yolk. The logic was that consuming dietary cholesterol directly raises blood cholesterol, increasing heart disease risk. However, extensive research has since shown a more complex picture. For most healthy people, dietary cholesterol from eggs has a minimal impact on blood cholesterol levels. The liver primarily controls the body's cholesterol production and can regulate its output to compensate for dietary intake.

The Shifting Focus to Saturated Fat

Instead of dietary cholesterol, health experts now place a greater emphasis on the intake of saturated and trans fats as key drivers of high LDL ("bad") cholesterol. While a large egg contains only a modest amount of saturated fat (about 1.6 grams), the bigger concern often lies in how eggs are prepared. The classic American breakfast of scrambled eggs with bacon, sausage, and butter on white toast can significantly increase a meal's saturated fat content, far outweighing the contribution from the egg itself. This shift in focus highlights the importance of overall dietary context rather than isolating eggs as a singular source of harm.

Potential Health Risks for Specific Groups

While a moderate intake of eggs (up to one per day) is generally considered safe for healthy individuals, some groups should exercise more caution. People with pre-existing heart disease, high LDL cholesterol, or type 2 diabetes may be more sensitive to dietary cholesterol and might need to limit their intake to fewer eggs per week. Additionally, the debate surrounding the compound Trimethylamine N-oxide (TMAO) is another area of concern. Choline, a nutrient abundant in egg yolks, is metabolized by gut bacteria into TMAO, which has been linked to an increased risk of cardiovascular disease in some studies. However, the data is conflicting, with other research showing no significant TMAO increase from moderate egg consumption.

Choline Metabolism and TMAO

Choline Source: Egg yolks are one of the richest dietary sources of choline, an essential nutrient important for brain and nerve function.
Metabolic Pathway: Gut bacteria convert choline into Trimethylamine (TMA), which is then processed by the liver into TMAO.
Conflicting Evidence: Some studies suggest a link between elevated TMAO and cardiovascular risk, while others show that the specific form of choline in eggs is absorbed differently and may not significantly raise TMAO levels.

Food Safety: The Salmonella Risk

Eggs can pose a food safety risk due to potential contamination with Salmonella bacteria. Salmonella can contaminate eggs either on the shell from bird droppings or internally while the egg is forming inside the hen. This risk is why safe handling and proper cooking are paramount. In the U.S., the FDA has implemented regulations to help prevent contamination, but consumer vigilance is still required.

How to Minimize Salmonella Risk

Refrigerate: Keep eggs refrigerated at 40°F (4°C) or colder.
Discard Cracked Eggs: Throw away any eggs with cracked shells, as bacteria can enter through these tiny openings.
Cook Thoroughly: Cook eggs until both the yolk and white are firm. Avoid consuming raw or undercooked eggs, especially by vulnerable populations like children, the elderly, and immunocompromised individuals.
Use Pasteurized Eggs: For recipes requiring raw or lightly cooked eggs, such as hollandaise or Caesar dressing, use pasteurized eggs or egg products.

Egg Allergies: A Common Concern

Egg allergy is one of the most common food allergies, especially in children. It occurs when the immune system overreacts to proteins in the egg whites and/or yolks. While many children outgrow their allergy by age 16, it can persist into adulthood. Symptoms can range from mild skin reactions (hives, eczema) to more severe respiratory or digestive issues. In rare cases, it can trigger anaphylaxis, a life-threatening reaction. Anyone with a diagnosed egg allergy must strictly avoid eggs and egg-containing products. For those with severe allergies, an EpiPen and immediate medical attention are necessary in case of accidental exposure.

Comparison of Egg-Related Health Considerations


Health Consideration	Concerns/Risks	Relevance for Most Healthy Individuals	Relevance for At-Risk Individuals	Mitigation/Management
Dietary Cholesterol	Historically linked to high blood cholesterol and heart disease.	Minimal impact on blood cholesterol due to liver regulation.	Higher risk of increased blood cholesterol; limit intake to ~7 per week.	Moderate consumption; focus on overall diet.
Saturated Fat	Contributes to high LDL cholesterol when consumed in excess.	Low-to-moderate amount from the egg itself.	Same, but compounded by other conditions; cooking methods are key.	Avoid cooking with saturated fats like butter or bacon grease; use heart-healthy oils.
Bacterial Contamination	Risk of Salmonella food poisoning from raw or undercooked eggs.	Manageable with proper handling and cooking.	Higher risk of severe illness; cook thoroughly and avoid raw eggs.	Refrigerate, cook thoroughly, discard cracked eggs, use pasteurized products for raw dishes.
Choline/TMAO	Potential link between gut-bacteria-derived TMAO and cardiovascular disease.	Conflicting evidence; some studies show no significant increase with moderate intake.	The link is still debated and requires more research.	Further research is needed; for now, moderate intake seems safest.
Allergies	Immune reaction to egg proteins, causing symptoms from mild to severe.	Not relevant for non-allergic individuals.	Severe risk of allergic reaction, including anaphylaxis.	Strict avoidance of eggs and egg products.

Conclusion: A Balanced Perspective

While some legitimate health concerns exist regarding eggs, the notion that they are inherently unhealthy for everyone is a misconception. The primary risks—elevated cholesterol for sensitive individuals, saturated fat from cooking methods, bacterial contamination, and allergies—can be managed with awareness and a balanced approach. For the majority of healthy people, eggs remain a nutrient-dense food packed with high-quality protein, vitamins, and minerals. The key lies in consuming them in moderation as part of a varied diet, choosing healthy cooking methods, and practicing proper food safety. As with any food, individual dietary needs and health conditions should always be considered. For personalized advice, it is always best to consult a healthcare provider.

Harvard Health Publishing offers further perspective on eggs and heart health.

Frequently Asked Questions

For the majority of healthy individuals, the cholesterol in eggs has a minimal effect on blood cholesterol levels because the body regulates its own cholesterol production. However, people with pre-existing heart conditions or diabetes should limit their intake.

Decades of research have failed to establish a direct link between moderate egg consumption (up to one a day) and increased heart attack risk in healthy people. The overall diet, especially intake of saturated and trans fats, is a more significant factor.

To avoid Salmonella, always refrigerate eggs, discard any with cracked shells, and cook them until both the yolk and white are firm. For dishes with raw eggs, use pasteurized egg products.

Yes, egg allergy is one of the most common food allergies, particularly affecting children. Symptoms can range from mild skin irritations to severe, life-threatening reactions.

Yes, a large egg contains about 1.6 grams of saturated fat, primarily in the yolk. However, the total amount is relatively low compared to other animal products like bacon or sausage.

TMAO is a compound produced when gut bacteria metabolize choline from eggs and other sources. Some research links elevated TMAO to increased cardiovascular risk, but the significance of this for people consuming a moderate number of eggs is still debated and inconclusive.

Egg whites are fat-free and cholesterol-free, making them a good option for those needing to reduce fat and cholesterol intake. However, the yolk contains most of the egg's vitamins, minerals, and antioxidants, so consuming the whole egg provides more comprehensive nutrition.