Two eggs daily can actually lower harmful cholesterol levels when eaten as part of a low saturated fat diet, according to new research that challenges decades of dietary advice.
The University of South Australia study, funded by the egg industry, reports that it definitively shows that saturated fat, not dietary cholesterol in eggs, drives up LDL cholesterol levels.
The world-first crossover study of 61 adults found that participants consuming two eggs daily alongside a low saturated fat diet experienced reduced LDL cholesterol compared to those following a high saturated fat diet with minimal eggs. The findings suggest it’s time to crack open our assumptions about this breakfast staple.
Separating Cholesterol from Saturated Fat
Researchers designed three distinct five-week diets to isolate the effects of cholesterol and saturated fat. The breakthrough came from comparing a high-cholesterol, low-saturated fat diet including two eggs daily against a low-cholesterol, high-saturated fat diet without eggs, plus a control diet high in both.
Only the egg-rich diet lowered LDL cholesterol levels—dropping from 109.3 to 103.6 mg/dL compared to the control. The egg-free high saturated fat diet showed no improvement. Across all participants, saturated fat intake correlated positively with LDL cholesterol while dietary cholesterol showed no correlation.
“Eggs have long been unfairly cracked by outdated dietary advice,” explained lead researcher Professor Jon Buckley from the University of South Australia. “They’re unique – high in cholesterol, yes, but low in saturated fat. Yet it’s their cholesterol level that has often caused people to question their place in a healthy diet.”
The Real Culprits Behind High Cholesterol
The study’s methodology reveals why previous research may have misidentified eggs as problematic. Earlier studies often examined egg consumption within typical Western diets already high in saturated fat, making it difficult to separate the effects of different dietary components.
Key findings include:
- Saturated fat intake strongly predicted LDL cholesterol elevation (β = 0.35, P = 0.002)
- Dietary cholesterol showed no relationship to blood cholesterol (β = −0.006, P = 0.42)
- Two eggs daily in a low saturated fat context reduced cardiovascular disease risk markers
The research comes at a critical time, with cardiovascular disease claiming nearly 18 million lives annually worldwide. In Australia, one person dies from heart disease every 12 minutes, accounting for one in four deaths nationwide.
Bacon, Not Eggs, Poses Heart Risk
Professor Buckley’s team delivered what he calls “hard-boiled evidence in defence of the humble egg.” The implications extend beyond breakfast choices to broader dietary patterns that emphasize reducing saturated fat rather than avoiding cholesterol-rich foods.
“When it comes to a cooked breakfast, it’s not the eggs you need to worry about – it’s the extra serve of bacon or the side of sausage that’s more likely to impact your heart health,” Buckley noted.
The study, funded by the Egg Nutrition Center—a division of the American Egg Board—involved a rigorous randomized, controlled design with participants serving as their own controls across different dietary phases. This approach minimized individual variations that could confound results.
However, the research revealed a nuanced picture. While eggs in a low saturated fat diet reduced overall LDL cholesterol, they also decreased larger LDL particles and increased smaller, more atherogenic particles. This suggests the cardiovascular benefits may be partially offset, though the overall effect remained positive.
The findings align with recent shifts in dietary guidelines that have moved away from strict cholesterol limits, instead emphasizing overall dietary patterns and saturated fat reduction for heart health.
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