Eggs, including the yolk, are considered a nutritious and healthy choice. If they impact your cholesterol, it’s usually on the ‘good’ kind. They can also positively affect ‘bad’ cholesterol, which could benefit your well-being.
Opinions on eggs vary—some see them as an incredible and budget-friendly source of protein and essential nutrients, while others argue that the yolks could increase the risk of heart disease.
So, are eggs good or bad for your health? This article delves into both perspectives to give you a well-rounded view.
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What makes eggs controversial in health discussions?
Whole eggs consist of two primary parts:
- Egg white: Mostly made of protein.
- Egg yolk: The yellow or orange part, packed with nutrients.
Historically, the health concern with eggs has centered around their cholesterol content, primarily found in the yolk.
Cholesterol is a fatty, waxy substance that’s both in certain foods and produced by our bodies. Large studies from a few decades ago drew connections between high blood cholesterol levels and heart disease.
In 1961, the American Heart Association advised people to reduce dietary cholesterol, and numerous international health organizations followed suit.
As a result, egg consumption declined considerably for several decades. Many people turned to cholesterol-free egg substitutes, believing they were a healthier alternative.
Summary: The main reason eggs came under health scrutiny was their high cholesterol content, which led to a decline in egg consumption and a rise in the use of cholesterol-free substitutes.
Eggs are high in cholesterol
Whole eggs, including the yolks, are indeed rich in cholesterol. They’re one of the main sources of cholesterol in a typical American diet.
For example, two large whole eggs (100 grams) pack around 411 mg of cholesterol, while 100 grams of 30% fat ground beef has only about 78 mg of cholesterol.
Until a few years ago, the recommended upper limit for daily cholesterol intake was 300 mg, or even less for those with heart issues.
However, recent research has changed this viewpoint. Many health organizations around the world no longer advise limiting dietary cholesterol.
For the first time in many years, the Dietary Guidelines for Americans, updated in December 2015, didn’t set an upper limit for cholesterol consumption.
Yet, a lot of people are still wary of eating eggs. They’ve heard that high dietary cholesterol equates to high blood cholesterol and heart disease risk.
But it’s crucial to note that just because a food is cholesterol-rich doesn’t mean it will automatically elevate your blood cholesterol levels.
Summary: Two large whole eggs contain 411 mg of cholesterol, which used to exceed the daily limit, but this restriction on dietary cholesterol has been lifted.
How eating eggs affects blood cholesterol
While you might think eating cholesterol-rich foods would increase your blood cholesterol, that’s usually not the case. Your liver churns out a good amount of cholesterol because your cells need it.
If you eat foods high in cholesterol, like eggs, your liver compensates by producing less. On the flip side, if your diet is low in cholesterol, your liver ups its production.
As a result, eating more cholesterol doesn’t lead to a significant change in blood cholesterol levels for most people.
One extensive, well-conducted study showed that eating egg yolks daily for a year didn’t noticeably alter total cholesterol, LDL (the bad kind) or HDL cholesterol, or the total-to-HDL cholesterol ratio in adults with early symptoms of age-related macular degeneration.
Another review of high-quality studies found that, in healthy individuals, eating foods rich in cholesterol did raise both LDL and HDL cholesterol levels. However, the LDL-to-HDL ratio, a key indicator of heart disease risk, remained unchanged.
Similarly, a study involving 30 people who ate 3 eggs daily for 13 weeks found that their total cholesterol, HDL, and LDL levels rose compared to those who only took a choline supplement. Yet, their LDL-to-HDL ratio remained consistent, leading researchers to conclude that dietary cholesterol helps regulate the body’s own cholesterol production to maintain this ratio.
It’s also worth noting that cholesterol isn’t the bad guy it’s often made out to be. It plays a role in several crucial bodily functions, including:
- Making vitamin D
- Producing steroid hormones like estrogen, progesterone, and testosterone
- Creating bile acids that help you digest fats
And let’s not forget, that cholesterol is a fundamental component of every cell membrane in your body, making it essential for life.
Summary: When you consume foods rich in cholesterol, your liver reduces its own production of cholesterol, resulting in little to no change in blood cholesterol levels while maintaining a steady HDL to LDL ratio.
Do eggs increase heart disease risk?
Multiple scientific research projects have looked into how eating eggs affects factors linked to heart health, and the results are mainly positive or neutral. Research indicates that having one or two eggs daily doesn’t appear to mess with your cholesterol or put your heart at risk.
One well-constructed study compared the impact of eating two eggs daily with oatmeal. It found no negative impact on heart health indicators and noted that people felt fuller after an egg breakfast than oatmeal.
Another quality study showed that having two eggs a day didn’t mess with cholesterol levels, bad cholesterol, or blood sugar control in overweight folks or with prediabetes or diabetes.
Yet another high-quality study focused on how eggs affect the lining of your heart and blood vessels, known as the endothelium. Having two eggs at breakfast for six weeks didn’t make a difference in cholesterol, blood flow, blood pressure, or weight, compared to those who had other types of breakfasts.
Eggs might even help to reduce your chances of developing metabolic syndrome. One expansive study showed that women who ate seven eggs a week had a lower risk of this condition than those who only ate one egg a week. Another study linked eating four to six eggs a week with a lowered risk of metabolic syndrome, compared to just one egg a month.
If you’re dealing with insulin resistance or type 2 diabetes, having eggs as part of a low-carb diet can improve heart health markers. For example, one study of people with prediabetes found that those who ate whole eggs on a carb-limited diet had better insulin sensitivity and heart health than those who ate only egg whites.
Another study of prediabetic individuals found that eating three eggs per day for three months reduced inflammation markers compared to an egg substitute on the same diet.
Good cholesterol usually increases when you eat eggs, while bad cholesterol stays the same or only slightly increases. Plus, omega-3-enriched eggs can help lower levels of triglycerides in your blood.
Further studies suggest that regularly eating eggs seems safe even for those with existing heart issues and might even be linked to fewer heart-related incidents.
A long-term study observed that people eating less than one egg per day had a reduced risk of heart problems, heart disease, and stroke as they aged. Another comprehensive study found no relationship between eating eggs and dying from heart-related issues. In men, it even found a reduced risk of death from strokes.
Finally, a comprehensive review of 17 studies involving over 260,000 participants found no connection between eating eggs and developing heart disease or suffering a stroke.
Summary: Studies indicate that egg consumption has neutral or beneficial effects on heart disease risk.
Do eggs increase diabetes risk?
Controlled scientific studies suggest that eating eggs could enhance insulin sensitivity and lessen factors that raise the risk of heart disease in individuals with prediabetes. However, there’s mixed evidence regarding the link between egg consumption and type 2 diabetes.
Suggested read: Is white rice healthy or bad for you?
A recent review of various studies found that eating up to seven eggs a week didn’t raise heart disease or type 2 diabetes markers significantly, whether in people with diabetes or without.
On the other hand, a review that analyzed two large-scale studies involving over 50,000 adults noted that those who ate at least one egg daily had a higher chance of developing type 2 diabetes compared to those who ate less than one egg a week.
Another study focused on women and revealed a link between high dietary cholesterol and increased diabetes risk, though it didn’t expressly point to eggs as the culprit.
Interestingly, a large study that didn’t find a connection between egg eating and heart attacks or strokes did notice a 54% higher risk of heart disease in people with diabetes who ate eggs.
So, for folks with prediabetes or diabetes, eggs could be a contentious issue. However, it’s crucial to remember that these observational studies rely on self-reported dietary habits.
Such studies only show a correlation between egg eating and a higher chance of developing diabetes; they don’t prove that eggs are the cause. These studies also don’t provide a full picture, like what else these individuals were eating, their level of physical activity, or other risk factors they may have had.
In contrast, controlled studies have shown that when eaten as part of a balanced diet, eggs may benefit people with diabetes.
For instance, one study found that diabetics who ate two eggs daily as part of a high-protein, high-cholesterol diet saw improvements in fasting blood sugar levels, insulin levels, and blood pressure, along with a rise in good cholesterol levels.
Further research associates eating eggs with better insulin sensitivity and lower inflammation in people with prediabetes or diabetes.
Summary: Various studies on eggs and diabetes provide mixed results. Observational studies indicate an increased risk of type 2 diabetes, while controlled trials show improved health markers.
Your genes may affect how you respond to egg consumption
While eggs are generally safe and healthy for most people, there’s a suggestion that the story could be different for individuals with specific genetic factors.
Suggested read: 6 reasons why eggs are the healthiest food on the planet
However, this area still needs more investigation to reach any solid conclusions.
The ApoE4 gene
If you have the ApoE4 gene, you’re at a higher risk for conditions like high cholesterol, heart disease, type 2 diabetes, and Alzheimer’s. But how does this relate to eating eggs?
One large observational study with over 1,000 men found no link between consuming a lot of eggs or cholesterol and heart disease risk for people carrying this gene.
However, in a controlled study with people who had normal cholesterol levels, eating a high-cholesterol diet that included many eggs significantly raised both total and bad cholesterol levels in those with the ApoE4 gene. This increase was more than double what was seen in people without the gene.
It’s worth noting that these individuals consumed around 3.5 eggs daily for three weeks. Eating just one or two eggs per day might not have had such a significant effect.
Also, these cholesterol spikes may be temporary. One study discovered that when ApoE4 carriers with normal cholesterol levels had an increase in blood cholesterol due to a high-cholesterol diet, their bodies actually started producing less cholesterol as a compensatory mechanism.
If you have familial hypercholesterolemia, you’re dealing with exceptionally high blood cholesterol levels and a heightened risk for heart disease. In situations like this, lowering cholesterol is crucial and typically involves medication and dietary changes.
It might be wise to steer clear of eggs for those with this genetic condition.
Dietary cholesterol hyper-responders
Some people are what we call “hyper-responders” to dietary cholesterol, meaning their blood cholesterol spikes when they eat foods high in cholesterol, like eggs.
Interestingly, both good (HDL) and bad (LDL) cholesterol levels often rise in these individuals when they consume such foods. Yet, some studies show that only LDL and total cholesterol significantly increased when hyper-responders upped their egg intake, while HDL levels remained stable.
Suggested read: 11 high-cholesterol foods: Which to eat, which to avoid
On a positive note, one study found that hyper-responders who ate 3 eggs daily for a month mainly experienced a rise in large LDL particles, which aren’t considered as risky as their smaller counterparts for heart health.
Moreover, there’s an added benefit for hyper-responders: they may absorb more antioxidants in the yellow part of the egg yolk. These antioxidants can be good for both eye and heart health.
Summary: Individuals with specific genetic traits may experience a greater increase in their cholesterol levels following egg consumption.
Eggs are loaded with nutrients
Eggs are a powerhouse of nutrients. They offer top-notch protein and a variety of essential vitamins and minerals.
Here’s the nutritional profile for one large whole egg:
- Calories: 72
- Protein: 6 grams
- Vitamin A: 10% of your daily need
- Riboflavin: 16% of your daily need
- Vitamin B12: 21% of your daily need
- Folate: 9% of your daily need
- Iron: 5% of your daily need
- Selenium: 28% of your daily need
Beyond these, eggs have even more nutrients, albeit in smaller quantities.
Summary: Eggs are rich in essential vitamins, minerals, and high-quality protein.
Eggs have many health benefits
Eating eggs can offer multiple health advantages, such as:
- Feeling full longer: Various studies indicate that eggs can help you feel fuller for an extended period, helping you eat less in your following meal.
- Weight loss: The high-quality protein in eggs can boost your metabolism, aiding in weight loss efforts.
- Brain health: Eggs are a valuable source of choline, a nutrient vital for brain function.
- Eye health: Eggs contain lutein and zeaxanthin, which help defend against eye conditions like cataracts and macular degeneration.
- Reduced inflammation: Eating eggs may help lower inflammation, which is associated with several health issues.
Summary: Eggs can aid in weight loss, protect the brain and eyes, and reduce inflammation.
Overall, eggs are a wholesome and nutrient-packed food.
For the majority, consuming eggs doesn’t significantly hike up cholesterol levels. When it does, it’s often the good cholesterol (HDL) that goes up, while also altering the size and shape of bad cholesterol (LDL) in a way that lessens the risk of health issues.
That said, individuals with specific medical conditions or genetic factors might need to be cautious about their egg consumption.