Understanding Why Were Eggs Considered Unhealthy in the Past

December 5, 2025 •

4 min read

In 1968, the American Heart Association (AHA) advised Americans to limit dietary cholesterol to 300 mg per day, specifically targeting eggs as a major source. This influential recommendation is the primary reason why were eggs considered unhealthy and led to decades of widespread public misconception about one of nature's most nutrient-dense foods.

Quick Summary

This article explores the historical origins of the myth linking eggs and poor health, focusing on the initial misunderstanding of dietary versus blood cholesterol. It explains the crucial difference between saturated fats and cholesterol, outlining the shift in nutritional science that led to modern, evidence-based dietary recommendations.

Key Points

Dietary Cholesterol Misconception: In the mid-20th century, it was wrongly assumed that dietary cholesterol from eggs directly raised blood cholesterol, leading to restrictive guidelines.
Saturated Fat is a Larger Factor: Modern science shows that saturated and trans fats have a much greater impact on raising 'bad' LDL cholesterol than dietary cholesterol for most people.
Compensatory Mechanisms: The human body naturally regulates its own cholesterol production, adjusting for dietary intake and minimizing the impact of egg consumption.
Overall Diet Matters Most: The health impact of eggs is heavily influenced by accompanying foods; meals high in saturated fats like bacon and butter are the real risk factor.
Eggs are Nutrient-Dense: Today, eggs are recognized as an affordable and high-quality source of protein, essential vitamins (A, D, B12), and nutrients like choline and lutein.
Guidelines Have Changed: Health organizations have dropped previous dietary cholesterol limits, reflecting the latest scientific understanding and rehabilitating the egg's reputation.

The Cholesterol Confusion: A Historical Perspective

The story of why eggs were vilified for so long is a classic tale of nutritional science evolving and correcting itself. Early research in the mid-20th century observed a correlation between high blood cholesterol levels and an increased risk of heart disease. In a time when data was less sophisticated, it was logically assumed that consuming foods high in dietary cholesterol would directly increase blood cholesterol. A single large egg contains around 186-213 mg of cholesterol, making it a prime target for restriction under guidelines that capped total intake at 300 mg per day.

This early, linear thinking failed to account for the body's complex metabolic processes. When we consume cholesterol, our body has a sophisticated feedback loop that down-regulates its own internal production to maintain balance. For the majority of the population, dietary cholesterol from eggs has only a minimal effect on blood cholesterol levels. The real culprit, as later research would reveal, was often a different dietary component entirely: saturated and trans fats.

The Saturated Fat Revelation

As nutritional science progressed, research began to distinguish between different types of fats and their impact on health. It became clear that saturated fat, and not dietary cholesterol for most people, is the primary driver of increased LDL ('bad') cholesterol production by the liver. Foods that are high in both saturated fat and cholesterol, such as bacon and sausage, were the more significant threat to heart health, and eggs were wrongly lumped into the same category.

This is why context matters. An egg eaten with processed meats like bacon and fried in butter is a different meal entirely than a poached egg on whole-grain toast with avocado. The former adds a high dose of saturated fat, while the latter is a heart-healthy choice. Observational studies that simply linked egg consumption to heart disease often failed to control for these confounding factors, leading to misleading conclusions.

The Vindication of the Egg

For decades, this outdated advice created a generation of egg-averse eaters, with many resorting to nutrient-poor substitutes. However, the tide has turned dramatically. Leading health organizations worldwide, including the U.S. Dietary Guidelines Advisory Committee, have removed previous daily limits on dietary cholesterol.

Nutritional Powerhouse:

Protein: Eggs offer a complete, high-quality protein source, containing all nine essential amino acids.
Vitamins & Minerals: They are packed with essential nutrients, including Vitamins A, D, B12, and selenium.
Brain Health: Egg yolks are one of the richest dietary sources of choline, a vital nutrient for brain health and fetal development.
Eye Health: Lutein and zeaxanthin, powerful antioxidants found in egg yolks, are crucial for protecting eye health and preventing age-related macular degeneration.

Historical vs. Modern Egg Guidelines: A Comparison


Feature	Historical View (c. 1960s-1990s)	Modern View (Post-2015)
Primary Concern	High dietary cholesterol in egg yolks directly raises blood cholesterol.	High saturated fat has a greater impact on blood cholesterol for most people.
Dietary Guideline	Limit intake to 3-4 eggs per week.	No specific limit for healthy individuals; eggs can be part of a healthy pattern.
Cholesterol Target	Limit dietary cholesterol intake to under 300 mg per day.	No specified daily limit for dietary cholesterol in most guidelines.
Confounding Factors	Often overlooked what eggs were consumed with, such as fatty bacon or sausage.	Emphasis placed on the overall diet pattern, not just isolated nutrients.
Nutrient Perspective	Focus was narrowly on the cholesterol content of the yolk.	Appreciates the full nutrient profile of eggs, including protein, vitamins, and antioxidants.

Ongoing Research and Nuances

While the general consensus is that eggs are healthy for most people, some specific population groups warrant continued research and personalized advice. For example, some individuals are genetically predisposed to be "hyper-responders" to dietary cholesterol. The evidence on egg consumption for people with pre-existing conditions like type 2 diabetes or heart failure has also shown mixed results in observational studies. These studies are complex, often struggling to isolate the effect of eggs from other dietary and lifestyle factors. However, randomized controlled trials generally show a more neutral or even beneficial effect. It's a reminder that nutrition is a highly individualized science and broader dietary context is key. To read a detailed review of the evolution of these dietary guidelines, see this publication: The Fifty Year Rehabilitation of the Egg.

Conclusion

For nearly 50 years, eggs were a dietary boogeyman, their reputation sullied by outdated science focused narrowly on cholesterol. The decades-long re-evaluation of nutrition science has overwhelmingly shown that for the vast majority of healthy adults, moderate egg consumption is not a risk factor for heart disease. Instead, eggs are a valuable source of protein, vitamins, and other beneficial nutrients. The real lesson learned is that focusing on overall dietary patterns—emphasizing vegetables, fruits, and whole grains while limiting saturated fat—is more important than fixating on a single nutrient like dietary cholesterol. Eggs are back on the menu, and their redemption is a testament to the continuous evolution of scientific understanding. Today, we understand that a whole egg is not just cholesterol, but a complete nutritional package, best enjoyed as part of a balanced diet.

Frequently Asked Questions

Eggs were considered unhealthy due to their high dietary cholesterol content. Early, less sophisticated research wrongly assumed that eating cholesterol directly raised blood cholesterol, leading to recommendations to limit egg consumption.

For the majority of people, moderate egg consumption has a minimal effect on blood cholesterol levels. The body compensates by reducing its own cholesterol production when more is consumed through diet.

For most people, it's what you eat with eggs that has a bigger impact. Foods high in saturated fats, like bacon and sausage, are more likely to raise blood cholesterol than the egg itself.

Yes, in 1968, the AHA issued a recommendation limiting dietary cholesterol to 300 mg per day and suggesting no more than three whole eggs per week. This advice was based on the limited science available at the time.

No, the color of an egg's shell depends on the breed of the hen and has no bearing on its nutritional value. Both brown and white eggs offer the same nutrients.

For most healthy individuals, moderate egg consumption—up to one per day—is considered safe and can be part of a balanced diet. Some older adults with healthy cholesterol levels can even consume two per day.

If you have a high LDL cholesterol level, diabetes, or other risk factors, it's wise to discuss egg consumption with your doctor. Some evidence suggests a need for moderation, but the focus should still be on a diet low in saturated fat.