Do Eggs Raise Bad Cholesterol? Research Clears the Confusion

For decades, eggs have been blamed for raising cholesterol and contributing to heart disease. The logic seemed simple — since eggs contain dietary cholesterol, they must increase bad cholesterol in the blood. But new research from the University of South Australia (UniSA) tells a different story.

Scientists have found that eggs themselves are not the enemy; it’s the saturated fat in the overall diet that drives cholesterol levels up, not the cholesterol found in eggs.

Link Between Eggs and Heart Disease

Cardiovascular disease (CVD) remains the world’s top cause of death, claiming nearly 19.8 million lives in 2022, according to the World Health Organization. About 85% of these deaths result from heart attacks and strokes, and most occur in low- and middle-income countries. Elevated blood cholesterol plays a major role in this statistic, often leading to blocked arteries and serious heart conditions.

Freepik | CVD is the leading global cause of death, with 85% being heart attacks and strokes.

Traditional dietary guidelines once warned against eating foods high in cholesterol — like eggs — assuming they would increase low-density lipoprotein (LDL), the “bad” cholesterol. But the UniSA study is reshaping that thinking. Researchers now point to saturated fat as the true culprit influencing blood lipids and heart health.

What the Research Actually Found

The UniSA study, led by Professor Jon Buckley, PhD, was a randomized, controlled, crossover trial designed to separate the effects of dietary cholesterol from saturated fat. Researchers wanted to understand whether eating eggs truly affected LDL cholesterol levels or if the problem came from other parts of the diet.

Participants — 54 healthy adults — followed three different diets over separate five-week periods. The order of these diets was randomized to ensure fair comparison. By the end of the study, 48 participants completed all three diet phases.

Each diet varied in its composition of cholesterol and saturated fat. When participants ate eggs as part of a low-saturated-fat diet, their LDL cholesterol actually decreased compared to those who avoided eggs entirely. The results revealed that eating two eggs daily not only didn’t raise bad cholesterol but also lowered the risk of heart disease when paired with a diet low in saturated fat.

Professor Buckley explained,

“Eggs have long been unfairly cracked by outdated dietary advice. They’re high in cholesterol, yes, but low in saturated fat. Our findings show that the cholesterol in eggs isn’t the issue — it’s the saturated fat in the rest of the diet that affects cholesterol levels.”

Breaking Down the Misconceptions

For years, the assumption that “cholesterol in food equals cholesterol in blood” guided public health messages. But the body’s response to dietary cholesterol is more complex. Here’s what researchers observed:

1. Saturated fat raises LDL cholesterol far more than dietary cholesterol does.
2. Eggs, despite being high in cholesterol, contain essential nutrients like protein, vitamins, and minerals.
3. When included in a balanced diet low in saturated fat, eggs can be part of a heart-healthy eating plan.

These findings challenge years of caution around eating eggs for breakfast. As Professor Buckley humorously put it,

“We’ve delivered hard-boiled evidence in defense of the humble egg. It’s not the eggs you should worry about — it’s the extra bacon or sausage on your plate.”

What This Means for Everyday Eating

Freepik | Packed with brain-and-muscle-supporting nutrients, eggs offer high-quality protein.

Eggs are one of the most nutrient-dense foods available, offering a combination of high-quality protein, choline, and vitamin D — nutrients that support brain and muscle function. The new research encourages people to rethink how they view eggs in relation to heart health.

When planning meals, the focus should shift to reducing sources of saturated fat, such as:

1. Processed meats like bacon, sausage, and salami
2. Full-fat dairy products
3. Fried foods cooked in butter or palm oil

Replacing these with healthier fats — such as those found in olive oil, nuts, and avocados — can have a greater impact on lowering LDL cholesterol than cutting out eggs.

A Fresh Perspective on a Classic Food

The UniSA findings bring clarity to years of dietary confusion. Eggs do not increase bad cholesterol when eaten as part of a low-saturated-fat diet. Instead, the focus should be on limiting foods high in saturated fat that truly affect heart health.

This research reinforces an important takeaway — nutrition advice continues to evolve as science advances. For those who enjoy eggs, it’s reassuring to know they’re not only safe but also beneficial when included wisely in a balanced diet.

So the next time an omelet is on the menu, there’s no need for guilt. It’s not the eggs that deserve the blame — it’s the saturated fat that does.