Why Dietary Cholesterol is Important – IDM IV

By Jason Fung, MD

Cholesterol is not the evil, dietary monster it is made out to be!  It is one of the most misunderstood substances on the planet, and consuming it in your diet could be lifesaving.  We would not be able to survive without it because it is such a vital nutrient.  Cholesterol, located in the plasma membrane of cell walls, is an essential component of every cell in the body. It is so critical for our survival that every single cell in the body, except for brain cells, has the ability to make cholesterol (1).
Cholesterol has many uses in the body.  It is the foundation of steroid hormones such as estrogen, progesterone, testosterone, vitamin D, and important hormones such as adrenaline and cortisol.  It is essential for proper brain and nervous system function and development (12).
Sources of Cholesterol
Approximately 25% of our daily requirements of cholesterol comes (~300 – 500 mg) comes from our diet and the remaining 75% of cholesterol is produced by the body itself (~800 – 1200 mg).  Of this cholesterol manufactured by the body, the liver produces approximately 20% of it while other cells in our body synthesize 80% (1).
Although our bodies are capable of producing so much cholesterol on its own, it is still very important to obtain cholesterol from dietary sources.  This is because cholesterol production in the body an extremely complex process, and places burden on the liver (2).
 LambThe Effects of Dietary Cholesterol on the Body
Eating foods high in cholesterol was initially thought to raise blood cholesterol levels and increase our chances of developing cardiovascular disease.  Over the years some of the most nutritious foods, such as eggs, butter and animal meats, became demonized by the health care profession.  As a result, foods high in natural cholesterols have virtually become extinct from our diets.

The only way to prevent the body from overproducing cholesterol is to consume a sufficient amount of dietary cholesterol and reduce carbohydrate intakeScreen Shot 2014-04-16 at 10.01.14 PM

For hundreds of years humans have had diets high in natural cholesterols without the consequences of cardiovascular disease or diabetes.  When dietary cholesterol is restricted, this initiates a crisis situation within the body.  The liver begins to overproduce an enzyme called HMG-CoA reductase, which results in the production of excess cholesterol from carbohydrates.  If you increase your carbohydrate intake and decrease your cholesterol intake, then you will force your body to produce excess cholesterol (2).

 We excrete most of the dietary cholesterol we consume

As a result, eating foods high in cholesterol have very little impact on our cholesterol levels.  The majority of our dietary cholesterol intake is not absorbed by the body and is excreted by our gut.  Most of the cholesterol we reabsorb is the cholesterol manufactured by our bodies.  Almost all of the cholesterol in the body is cholesterol that has been produced by our body, and not from our diet.  Therefore, restricting our dietary intake of cholesterol has little effect on our cholesterol levels (1).
How the War Against Cholesterol Originated
During the 1960s, Ancel Keys, a scientist from the University of Minnesota, was studying the effects of diet and coronary disease.  He compared the dietary fat intake from subjects in seven different countries and noted their mortality rates.  In the famous Seven Countries study (an, ahem, association study) he concluded: cholesterol levels predicted risk for heart disease; the amount of saturated fat in the diet predicted cholesterol levels; and monounsaturated fat protected against heart disease (3).
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Ancel Keys had selectively picked through his data to generate results that would support his hypothesis (4).

“There is considerable range of serum cholesterol levels within the Framingham Study Group.  Something explains this inter-individual variation, but it is not diet.”

– Tavia Gordon, National Institute of Health 

The large Framingham Heart Study demonstrated no discernible relationship between reported dietary cholesterol intake and serum cholesterol levels.  Their results actually indicate high serum cholesterol levels are probably protective against cardiovascular disease.  They found cardiovascular related mortality rates to be much lower in individuals with high serum cholesterol levels, and much higher in those with low serum cholesterol levels (5).  Unfortunately, these results were never published because researcher could not believe the findings at the time (6).
Many studies since the Framingham Heart Study have suggested elevated serum cholesterol levels may be protective against death from cardiovascular disease (78).  A more recent study demonstrates people who have low serum cholesterol levels were twice as likely to die from heart attacks than people with high serum cholesterol levels (9).  Most research indicates that low serum cholesterol levels are potentially much more dangerous and place individuals at a higher risk for cardiovascular related death.  No study to date has yet to demonstrate that there is any relationship between dietary cholesterol and serum cholesterol levels, or between serum cholesterol levels and cardiovascular disease.
When Cholesterol Can Be Harmful 

Cholesterol is only harmful if is in its oxidized forms.  One of the ways cholesterol becomes oxidized is during the processing of foods such as reduced fat milk, powdered milk and powdered egg.  Inflammatory processes can also cause healthy cholesterol to oxidize within the body, which results in the production of dangerous arterial plaques (27).  

High Density Lipoprotein (HDL) and Low Density Lipoprotein (LDL) “Cholesterols”
Neither HDL nor LDL are actual cholesterols.  They are actually protein transport mechanisms for cholesterol within the body.  LDL molecules carry cholesterol away from the liver to other organs and extremities for many reasons such as, the production of steroid hormones and the transpiration of critical fat soluble nutrients.  HDL molecules return the same cholesterol back to the liver so it can be recycled.  Cholesterols are never present in the bloodstream without LDL or HDL molecules to carry them from Point A to Point B (8).
When your doctor checks your serum cholesterol levels the lab reports it by weight.  When you serum cholesterol level is high, this means in a given measure of blood volume the total number of cholesterol-carrying lipoprotein particles weigh more (9).  This could mean one of two things: you have more particles or the particles weigh more because they are carrying more cholesterol. Large LDL particles that weight more (carrying more cholesterol) are actually very safe.  Small, dense LDL particles are the pesky ones (carrying less cholesterol) that can increase your risk heart disease.  This is because these particles are more susceptible to oxidation, thus, triggering an unwanted inflammatory response.  These smaller LDL particles are often found in processed and refined carbohydrates.  Diets high in these carbohydrates and in the presence of excess insulin are responsible for the production of the small, dense LDL particles.  Diets rich in natural fats and moderate protein with low carbohydrate intake result in normal LDL levels (2).  The only way to avoid these small LDL particles is to eliminate your consumption of refined and processed carbohydrates.
Dietary Approach to Prevent Cardiovascular DiseaseShrimp
To reduce your chances of developing cardiovascular disease or experiencing any cardiovascular related events, it is important you follow the following dietary recommendations:

  1. Have a normal, unrestricted intake of dietary cholesterol and healthy natural fats
  2. Eat foods from animal sources because they are rich in fat, cholesterol and complete proteins
  3. Avoid highly processed and rancid vegetable oils and trans fats
  4. Eliminator or reduce your consumption of refined carbohydrates and starchy foods

Below is a table from the USDA’s database of the top 20 foods high in cholesterol.
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Cholesterol Friendly Recipes
Coconut Oil Omelet with Avocado (serves 1)Slide1

  • 1 chopped onion
  • 1 chopped tomato
  • 2 eggs
  • 1 tbsp of virgin coconut oil
  • 1/4 sliced avacado
  • Sea salt and freshly ground pepper to taste
  • Salsa (optional)
  1. Beat the eggs in a bowl
  2. Add in the chopped onion, tomato, sea salt, freshly ground pepper into the bowl with the eggs and mix
  3. Add the virgin coconut oil to a skillet and place on medium heat
  4. Add the egg mixture once the coconut oil has liquified and cook for approximately 2 minutes
  5. Flip the omelet and cook for another minute
  6. Remove the omelet from the skillet and serve with avocado slices and salsa

Slide1Shrimp Scampi (serves ~4)

  • 2 lbs of fresh shrimp
  • 1/2 cup unsalted butter
  • 6 cloves of pressed garlic
  • 1 tsp of lemon zest
  • 2 tbsp of freshly squeezed lemon juice
  • Sea Salt and cayenne pepper to taste
  • 1/4 cup of chopped, fresh parsley


  1. Preheat your oven to 400 F (or 200 C)
  2. Melt the butter in a baking pan inside of the oven
  3. Once the butter has melted add the garlic, sea salt, cayenne pepper, and 1 tbsp of the parsley
  4. Stir well and bake uncovered for 5 minutes
  5. Flip the shrimp over and add the lemon juice, lemon zest, the rest of the chopped parsley, and stir
  6. Cook for another 10 minutes (or until ready)
  7. Remove from the pan and pour the remaining garlic butter over the shrimp

Veal StewSlide1

  • 1 tbsp extra virgin olive oil
  • 1 tbsp of unsalted butter
  • 1 lb of  veal cut into cubes approximately 1″ thick
  • 1 sprig fresh tarragon or 1/2 tsp dried tarragon
  • 1 pound spring onions
  • Sea salt and freshly ground black pepper to taste
  • 1/4 to 1/2 cup of water
  • 1 cup fresh shelled peas, snow peas or frozen peas
  • 1/2 cup of diced carrots
  • 1/2 cup of sliced celery
  1. Place a 12″ skillet on the stove and turn the burner to high heat
  2. Add the oil and butter to the skillet until
  3. Add the meat once the butter and oil are warmed
  4. Allow the meat to brown on the bottom for about 5 minutes
  5. Add the tarragon, onions, sea salt and pepper
  6. Stir occasionally until the onions are soft and the meat stuck to the bottom of the skillet is released
  7. Add the water and stir
  8. Reduce to low heat, cover and cook for 15 to 20 minutes
  9. Uncover the skillet, add the peas, carrots and celery, and raise the heat to medium, and cook for about 5 minutes



By The Fasting Method

For many health reasons, losing weight is important. It can improve your blood sugars, blood pressure and metabolic health, lowering your risk of heart disease, stroke and cancer. But it’s not easy. That’s where we can help.

Jason Fung, MD

By Jason Fung, MD

Jason Fung, M.D., is a Toronto-based nephrologist (kidney specialist) and a world leading expert in intermittent fasting and low-carb diets.

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