Eggs are among the most nutritious foods on
the planet.
Just imagine… a whole egg contains all
the nutrients needed to turn a single cell into an entire baby
chicken.
However, eggs have gotten a bad reputation
because the yolks are high in cholesterol.
In fact, a single medium sized egg contains
186 mg of cholesterol, which is 62% of the recommended daily
intake.
People believed that if you ate cholesterol,
that it would raise cholesterol in the blood and contribute
to heart disease.
But it turns out that it isn’t that simple.
The more you eat of cholesterol, the less your body produces
instead.
Let me explain how that works…
How Your Body Regulates Cholesterol Levels
Eggs in a Basket
Cholesterol is often seen as a negative word.
When we hear it, we automatically start thinking
of medication, heart attacks and early death.
But the truth is that cholesterol is a very
important part of the body. It is a structural molecule that
is an essential part of every single cell membrane.
It is also used to make steroid hormones like
testosterone, estrogen and cortisol.
Without cholesterol, we wouldn’t even
exist.
Given how incredibly important cholesterol
is, the body has evolved elaborate ways to ensure that we always
have enough of it available.
Because getting cholesterol from the diet isn’t
always an option, the liver actually produces cholesterol.
But when we eat a lot of cholesterol rich foods,
the liver starts producing less (1,
2).
So the total amount of cholesterol in the body
changes only very little (if at all), it is just coming from
the diet instead of from the liver (3,
4).
Bottom Line: The liver produces large amounts of cholesterol.
When we eat a lot of eggs (high in cholesterol), the liver produces
less instead.
What Happens When People Eat Several Whole
Eggs Per Day?
Woman Smiling and Holding a Fried Egg
For many decades, people have been advised
to limit their consumption of eggs, or at least of egg yolks
(the white is mostly protein and is low in cholesterol).
Common recommendations include a maximum of
2-6 yolks per week. However, there really isn’t much scientific
support for these limitations (5).
Luckily, we do have a number of excellent studies
that can put our minds at ease.
In these studies, people are split into two
groups… one group eats several (1-3) whole eggs per day,
the other group eats something else (like egg substitutes) instead.
Then the researchers follow the people for a number of weeks/months.
These studies show that:
•In almost all cases, HDL (the “good”) cholesterol
goes up (6, 7, 8).
•Total and LDL cholesterol levels usually
don’t change, but sometimes they increase slightly (9,
10, 11, 12).
•Eating Omega-3 enriched eggs can lower
blood triglycerides, another important risk factor (13, 14).
•Blood levels of carotenoid antioxidants
like Lutein and Zeaxanthine increase significantly (15, 16,
17).
It appears that the response to whole egg consumption
depends on the individual.
In 70% of people, it has no effect on Total
or LDL cholesterol. However, in 30% of people (termed “hyper
responders”), these numbers do go up slightly (18).
That being said, I don’t think this is
a problem. The studies show that eggs change the LDL particles
from small, dense LDL to Large LDL (19, 20).
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, this is not a
cause for concern (21, 22, 23).
The science is clear that up to 3 whole eggs
per day are perfectly safe for healthy people who are trying
to stay healthy.
Bottom Line: Eggs consistently raise HDL (the “good”)
cholesterol. For 70% of people, there is no increase in Total
or LDL cholesterol. There may be a mild increase in a benign
subtype of LDL in some people.
Eggs and Heart Disease
Egg
Many studies have looked at egg consumption
and the risk of heart disease.
All of these studies are so-called observational
studies. In studies like these, large groups of people are followed
for many years.
Then the researchers use statistical methods
to figure out whether certain habits (like diet, smoking or
exercise) are linked to either a decreased or increased risk
of some disease.
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. Some
of the studies even show a reduced risk of stroke (24, 25, 26).
However… one thing that is worth noting,
is that these studies show that diabetics who eat eggs are at
an increased risk of heart disease (27).
Whether the eggs are causing the increased
risk in diabetics is not known. These types of studies can only
show a correlation and it is possible that the diabetics who
eat eggs are, on average, less health conscious than those who
don’t.
This may also depend on the rest of the diet.
On a low-carb diet (by far the best diet for diabetics), eggs
lead to improvements in heart disease risk factors (28, 29).
Bottom Line: Many observational studies show that people who
eat eggs don’t have an increased risk of heart disease,
but some of the studies do show an increased risk in diabetics.
Eggs also taste amazing and are incredibly
easy to prepare.
So even IF eggs were to have mild adverse effects
on blood cholesterol (which they don’t), the benefits
of consuming them would still far outweigh the negatives.
Bottom Line: Eggs are among the most nutritious foods on the
planet. They contain important brain nutrients and powerful
antioxidants that can protect the eyes.
How Much is Too Much?
Chicken and Egg, Smaller
Unfortunately, we don’t have studies
where people are fed more than 3 eggs per day.
It is possible (although unlikely) that eating
even more than that could have a detrimental effect on health.
Eating more than 3 is uncharted territory, so to speak.
However… I did find an interesting case
study (a study with only one individual). It was an 88 year
old man who consumed 25 eggs per day.
He had normal cholesterol levels and was in
very good health (37).
Of course, a study of one doesn’t prove
anything, but it’s interesting nonetheless.
It’s also important to keep in mind that
not all eggs are the same. Most eggs at the supermarket are
from chickens that are raised in factories and fed grain-based
feeds.
The healthiest eggs are Omega-3 enriched eggs,
or eggs from hens that are raised on pasture. These eggs are
much higher in Omega-3s and important fat-soluble vitamins (38,
39).
Overall, eating eggs is perfectly safe, even
if you’re eating up to 3 whole eggs per day.
I personally eat 3-6 whole eggs per day (about
30-40 per week) and my health has never been better.
Given the incredible range of nutrients and
powerful health benefits, quality eggs may just be the healthiest
food on the planet.