Eggs are among the most nutritious foods on the planet. In fact, a whole egg contains all the nutrients needed to turn a single cell into an entire chicken.
However, eggs have gotten a bad reputation because the yolks are high in cholesterol.
But cholesterol isn’t that simple. The more of it you eat, the less your body produces.
For this reason, eating a few eggs won’t cause a high rise in cholesterol levels.
This article explains this process and discusses how many eggs you can safely eat per day.
How Your Body Regulates Cholesterol Levels
Cholesterol is often viewed as negative.
This is because some studies have linked high levels of cholesterol with heart disease and early death. However, the evidence is mixed.
The truth is that cholesterol plays a very important function in your body. It’s a structural molecule that is essential to every cell membrane.
It is also used to make steroid hormones like testosterone, estrogen and cortisol.
Given how important cholesterol is, your body has evolved elaborate ways to ensure that it always has enough available.
Because getting cholesterol from the diet isn’t always an option, your liver produces enough to meet your body’s needs.
But when you eat a lot of cholesterol-rich foods, your liver starts producing less to keep cholesterol levels from becoming excessively high.
Therefore, the total amount of cholesterol in your body changes only very little, if at all. What changes is its source — your diet or your liver.
Nevertheless, you should still avoid eating excessive amounts of cholesterol if your blood levels are raised. A high intake may cause a moderate increase in blood cholesterol levels.
Your liver produces large amounts of cholesterol. When you eat cholesterol-rich foods such as eggs, your liver compensates by producing less.
What Happens When People Eat Several Whole Eggs per Day?
For many decades, people have been advised to limit their consumption of eggs — or at least of egg yolks.
A single medium-sized egg contains 186 mg of cholesterol, which is 62% of the recommended daily intake (RDI). In contrast, the white is mostly protein and low in cholesterol.
Common recommendations include a maximum of 2–6 yolks per week. However, scientific support for this limitation is lacking.
A few studies have examined the effects of eggs on cholesterol levels.
These studies divided people into two groups — one group ate 1–3 whole eggs per day while the other ate something else, such as egg substitutes.
These studies show that:
In almost all cases, “good” HDL cholesterol goes up.
Total and “bad” LDL cholesterol levels usually remain unchanged but sometimes increase slightly.
Eating omega-3-enriched eggs can lower blood triglycerides, another important risk factor.
Blood levels of carotenoid antioxidants like lutein and zeaxanthin increase significantly.
It appears that the response to eating whole eggs depends on the individual.
In 70% of people, eggs had no effect on total or “bad” LDL cholesterol. However, in 30% of people — called hyper-responders — these markers do go up slightly.
Although eating a few eggs per day may raise blood cholesterol in some people, they change the “bad” LDL particles from small and dense to large.
People who have predominantly large LDL particles have a lower risk of heart disease. So even if eggs cause mild increases in total and LDL cholesterol levels, it’s not a cause for concern.
The science is clear that up to 3 whole eggs per day are perfectly safe for healthy people.
Eggs consistently raise HDL (the “good”) cholesterol. For 70% of people, there is no increase in total or LDL cholesterol. Some people may experience a mild increase in a benign subtype of LDL.
Eggs and Heart Disease
Multiple studies have examined egg consumption and heart disease risk.
Many of these are observational studies in which large groups of people are followed for many years.
Researchers then use statistical methods to determine whether certain habits — like diet, smoking or exercise — are linked to either a decreased or increased risk of certain diseases.
These studies — some of which include hundreds of thousands of people — consistently show that people who eat whole eggs are no more likely to develop heart disease than those who don’t.
Some of the studies even show a reduced risk of stroke.
However, this research suggests that people who have type 2 diabetes and eat a lot of eggs have an increased risk of heart disease.
One controlled study in people with type 2 diabetes found that eating two eggs per day, six days a week, for three months did not significantly affect blood lipid levels.
Health effects may also depend on the rest of your diet. On a low-carb diet — which is the best diet for people with diabetes — eggs lead to improvements in heart disease risk factors.