For decades, eggs have been vilified as dietary villains that clog your arteries and spike your cholesterol levels. This fear has driven countless people to swear off Sunday morning omelets or carefully ration their egg consumption to just a few per week. Eggs have been unfairly labeled for decades. Current evidence shows that cholesterol in eggs is not the main driver of high LDL cholesterol – saturated fat is.
The latest scientific evidence from multiple groundbreaking studies is completely rewriting the story about eggs and cholesterol. Ready to discover what’s really raising your cholesterol numbers? Let’s dive into the surprising truth that’s turning nutritional wisdom on its head.
The Landmark University of South Australia Study Changes Everything
In this randomized, controlled, cross-over study (clinicaltrials.gov, NCT05267522), 61 adults (age 39 ± 12 y, BMI 25.8 ± 5.9 kg/m2) with baseline LDL cholesterol <3.5 mmol/L (135.3 μg/dL) were assigned to 3 isocaloric diets for 5 wk each: high-cholesterol (600 mg/d), low-saturated fat (6%) including 2 eggs/d (EGG); low-cholesterol (300 mg/d), high-saturated fat (12%) without eggs (EGG-FREE); and a high-cholesterol (600 mg/d), high-saturated fat (12%) control diet (CON) including 1 egg/wk. Compared with CON, EGG but not EGG-FREE reduced LDL cholesterol (CON 109.3 ± 3.1 μg/dL compared with EGG 103.6 ± 3.1 μg/dL P = 0.02 compared with EGG-FREE 107.7 ± 3.1 μg/dL, P = 0.52).
In a world-first study, researchers examined the independent effects of dietary cholesterol and saturated fat on LDL cholesterol (the ‘bad’ kind), finding that eating two eggs a day – as part of a high cholesterol but low saturated fat diet – can actually reduce LDL levels and lower the risk of heart disease. This represents the most comprehensive examination of how eggs affect cholesterol when isolated from other dietary factors.
Across all diets, saturated fat intake was positively correlated with LDL cholesterol (β = 0.35, P = 0.002), whereas dietary cholesterol was not (β = −0.006, P = 0.42). These findings demolish the long-held assumption that dietary cholesterol from eggs directly translates to higher blood cholesterol.
Saturated Fat Is the Real Culprit Behind High Cholesterol
Decades science has proven that saturated fats can raise your “bad” cholesterol and put you at higher risk for heart disease. Eating too much saturated fat can raise the level of LDL(bad) cholesterol in your blood. The overwhelming scientific consensus points to saturated fat as the primary dietary driver of elevated cholesterol levels.
Studies in animals have shown that saturated fats increase LDL cholesterol by inhibiting LDL receptor activity and enhancing apolipoprotein (apo)B-containing lipoprotein production. This mechanism explains why saturated fat has such a pronounced effect on cholesterol metabolism compared to dietary cholesterol itself.
Cholesterol metabolism is complex, with saturated fat known to have a more significant contribution at raising levels of low-density lipoprotein (LDL) cholesterol, a well-established risk factor for cardiovascular disease (CVD). Cholesterol metabolism is complex, with saturated fat known to have a more significant contribution at raising levels of low-density lipoprotein (LDL) cholesterol, a well-established risk factor for cardiovascular disease (CVD).
The Hidden Sources of Saturated Fat in Your Diet
Saturated fats are found in animal-based foods such as beef, pork, poultry, full-fat dairy products, eggs and tropical oils, such as coconut and palm. Many people unknowingly consume excessive amounts of saturated fat through seemingly innocuous food choices throughout their day.
Whole milk, butter and full-fat yogurt and cheese are high in saturated fat. Steak, beef roast, ribs, pork chops and ground beef tend to have high saturated fat and cholesterol content. These common foods can quickly push your saturated fat intake beyond recommended levels.
French fries, fried chicken with skin and other foods cooked in a deep fryer have a high amount of saturated fat and cholesterol from the oil they’re cooked in. Cookies, cakes and doughnuts usually contain butter or shortening, making them high in saturated fat and cholesterol.
Trans Fats Are Even More Dangerous Than Saturated Fats
Of all the fats, trans fat is the worst for your health. Too much trans fat in your diet increases your risk for heart disease and other health problems. Trans fats create a double-whammy effect on your cholesterol profile that makes them particularly harmful.
Trans fats raise your bad (LDL) cholesterol levels and lower your good (HDL) cholesterol levels. This dual action makes trans fats significantly more dangerous than saturated fats, which primarily affect LDL cholesterol.
Trans fats are found in many processed and packaged foods. Note that these foods are often low in nutrients and have extra calories from both fat and sugar: Cookies, pies, cakes, biscuits, sweet rolls, and donuts The combination of poor nutritional value and harmful fats makes these foods particularly problematic for cholesterol management.
Why Eggs Got Blamed Unfairly for Decades
Remember when experts said to avoid cholesterol-rich foods like eggs? The thought was that cholesterol in food raised your blood cholesterol and risk of heart disease. However, recent studies have found that some high-cholesterol foods may not raise your heart disease risk after all.
Egg consumption recommendations have fluctuated over time due to the belief that increased intake of dietary cholesterol raises plasma low density lipoprotein cholesterol (LDL-C) and therefore cardiovascular disease risk. Research suggests it is saturated fat, rather than dietary cholesterol, that is implicated in this association, yet controversy over egg consumption remains.
About two-thirds of the population has minimal to no response to even large amounts of dietary cholesterol and are known as compensators or hypo-responders. Alternatively, a small percentage of the population is considered hyper-responders or noncompensators, as they are sensitive to dietary cholesterol and experience much larger increases in blood cholesterol after eating cholesterol-rich foods This explains why individual responses to eggs vary so dramatically.
The Framingham Study Shows Eggs Actually Lower Cholesterol
Among men, consuming ≥5 (compared with <0.5) eggs/wk was associated with an 8.6 mg/dL lower total cholesterol level and a 5.9 mg/dL lower LDL cholesterol level, as well as lower triglycerides. Among men, consuming ≥5 (compared with <0.5) eggs/wk was associated with an 8.6 mg/dL lower total cholesterol level and a 5.9 mg/dL lower LDL cholesterol level, as well as lower triglycerides.
Consuming ≥5 eggs/wk was not adversely associated with lipid outcomes. This long-term observational study challenges decades of dietary recommendations that limited egg consumption for heart health.
Overall, higher egg intake combined with higher dietary fiber (compared with lower intakes of both) was associated with the lowest total cholesterol, LDL cholesterol, and LDL cholesterol–to–HDL cholesterol ratio. Finally, diets with higher (compared with lower) egg intakes in combination with higher total fish or fiber intakes, respectively, were associated with lower risks of developing elevated (>160 mg/dL) LDL cholesterol levels
How Food Processing Creates the Real Cholesterol Villains
In the past, most of the trans fat in foods came from partially hydrogenated oils (PHOs), formed through a manufacturing process that converts vegetable oil into a solid fat at room temperature. Food processing transforms relatively harmless ingredients into cholesterol-raising compounds.
The difference between these two comes down to the placement of a hydrogen atom; cis fats, found in natural foods like fish or walnuts, have a kink in their structure caused by two side-by-side hydrogen atoms, whereas trans fats, found in processed foods like margarine or anything fried, have a straight-chain structure caused by two opposing hydrogen atoms.
Many high-fat foods such as pizza, baked goods, and fried foods have a lot of saturated fat. Eating too much fat can add extra calories to your diet and cause you to gain weight. The processing and preparation methods often determine whether a food raises cholesterol levels.
Recent Research on Fortified Eggs Shows No Cholesterol Impact
However, results from a prospective, controlled trial show that over a four-month period cholesterol levels were similar among people who ate fortified eggs most days of the week compared with those who didn’t eat eggs. However, results from a prospective, controlled trial presented at the American College of Cardiology’s Annual Scientific Session show that over a four-month period cholesterol levels were similar among people who ate fortified eggs most days of the week compared with those who didn’t eat eggs.
Results showed a -0.64 mg/dL and a -3.14 mg/dL reduction in HDL-cholesterol (“good” cholesterol) and LDL cholesterol (“bad” cholesterol), respectively, in the fortified egg group. While these differences weren’t statistically significant, the researchers said the differences suggest that eating 12 fortified eggs each week had no adverse effect on blood cholesterol.
What This Means for Your Daily Diet Choices
While eggs themselves don’t “lower” cholesterol, replacing high-saturated-fat foods (like pastries, fried foods, or processed meats) with eggs can improve cholesterol levels overall. The swap reduces saturated fat intake while still providing high-quality nutrition. In other words: it’s not about avoiding eggs – it’s about what you eat with them.
Cook smart: Skip the butter and fry eggs in a non-stick pan, olive oil, or poach/boil instead. Pair wisely: Eat eggs with vegetables, avocado, or whole-grain toast – not bacon and sausage every morning. The preparation method and accompanying foods matter more than the eggs themselves.
For most healthy adults, 7–14 eggs per week can fit into a balanced diet. This represents a dramatic increase from traditional recommendations that limited egg consumption to three per week.
The evidence is clear: eggs aren’t the cholesterol villains we thought they were. Saturated fats and trans fats are the real culprits behind elevated cholesterol levels, while eggs can actually be part of a heart-healthy diet when prepared properly and consumed as part of a balanced nutritional approach. The next time you’re at the grocery store, you might want to worry less about the egg aisle and more about avoiding processed foods, fried items, and high-saturated-fat products. What surprises you most about these new findings?
