Fun Fact: Researchers Crack the Myth of High Cholesterol and Eggs

For many years, eggs have been unfairly blamed for high cholesterol and heart disease. The theory was that because eggs contain dietary cholesterol, they must be a major contributor to high blood pressure, high cholesterol, and cardiovascular disease (CVD). However, new research findings from the University of South Australia (UniSA) are challenging this theory. The study findings reveal that the real culprit is not the cholesterol in eggs, but rather the saturated fat in the overall diet.^1,2

“Eggs have long been unfairly cracked by outdated dietary advice,” Jon Buckley, PhD, lead researcher and professor at UniSA, said in a news release. “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.”²

CVD is the leading cause of death globally, accounting for an estimated 19.8 million deaths in 2022, which represents nearly 32% of all global deaths, according to the World Health Organization. Additionally, 85% of CVD-related deaths were due to heart attack and stroke. Research has found that more than three-quarters of CVD deaths occur in low- and middle-income countries.^1,3

Elevated blood cholesterol is a primary cause of CVD and death globally. Historically, dietary advice focused on reducing cholesterol intake because of its connection to higher low-density lipoprotein (LDL) cholesterol, which contributes to clogged arteries. However, new research suggests that the saturated fat in an individual’s diet is a more significant factor in negatively affecting blood lipids and increasing the risk of CVD than the cholesterol consumed—or eggs.^1,2

To further assess the independent effects of dietary cholesterol and saturated fat on LDL cholesterol, researchers conducted the first-known randomized, controlled, crossover study. The main goal of the study was to determine how eating eggs affects blood lipids and lipoproteins, specifically assessing whether saturated fat, not dietary cholesterol, was the real cause of any negative changes in lipid profiles.^1,2

Researchers compared the effects of 3 different diets on the blood lipid profiles of healthy adults. Each of the 3 diets was consumed for 5 weeks, and the order was randomly assigned for each participant to prevent any single diet from consistently being eaten first or last. A total of 54 participants completed the first phase, 49 completed the first 2 phases, and 48 completed all 3 diet phases.^1,2

“In this study, we separated the effects of cholesterol and saturated fat, finding that high dietary cholesterol from eggs, when eaten as part of a low saturated fat diet, does not raise bad cholesterol levels. Instead, it was the saturated fat that was the real driver of cholesterol elevation,” Buckley said in the news release.²

The results demonstrated that eating 2 eggs daily reduced LDL levels and lowered the risk of heart disease as part of a high cholesterol but low saturated fat diet. Specifically, compared with consuming a controlled diet, individuals who consumed eggs presented with lower LDL than individuals with an egg-free diet.^1,2

“You could say we’ve delivered hard-boiled evidence in defense of the humble egg,” Buckley concluded. “So, 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.”²

REFERENCES

1. Carter S, Hill AM, Yandell C, Wood L, Coates AM, Buckley JD. Impact of dietary cholesterol from eggs and saturated fat on LDL cholesterol levels: a randomized cross-over study. Am J Clin Nutri. 2025;122(1):83-91. doi:10.1016/j.ajcnut.2025.05.001

2. Sunny side up for eggs and cholesterol. News release. University of South Australia. July 18, 2025. Accessed August 19, 2025. https://unisa.edu.au/media-centre/Releases/2025/sunny-side-up-for-eggs-and-cholesterol/

3. Cardiovascular diseases (CVDs). World Health Organization. July 31, 2025. Accessed August 19, 2025. https://www.who.int/news-room/fact-sheets/detail/cardiovascular-diseases-(cvds)