Eating cholesterol rich food may not raise your blood cholesterol

A common notion held by many has been that if you eat food high in cholesterol your blood cholesterol rises. Science refutes this claim.

Eat eggs, shrimps and the like without guilt or the fear that your cholesterol will shoot up. Be cautious however if you are diabetic.

For many years, high blood cholesterol has been equated to CVD(Cardiovascular disease). CVD includes diseases of the blood vessels supplying the heart leading to heart attack, and blood vessels of the brain leading to stroke. It may also affect blood vessels in other parts of the body.

CVD is the leading cause of death in the United States and many other developed countries.

The recommended intake of cholesterol in the diet was limited to 300mg per day for many years. It was thought that eating large amounts of cholesterol raised blood levels of cholesterol.

The 2015–2020 Dietary Guidelines for Americans removed this restriction as extensive research showed no correlation between dietary cholesterol and blood cholesterol.

Note however that many foods with high cholesterol also are high in saturated fats and trans fats, both of which raise LDL cholesterol and the risk of CVD.

What is cholesterol?

Cholesterol is a waxy substance found in the body. It is a kind of fat which does not dissolve in water and is carried in the blood stream.

The liver makes cholesterol and we also eat foods which contain cholesterol.

Our blood cholesterol level, which we are so concerned about, is a mix of cholesterol made by the body and the food we ingest. 85% of the blood cholesterol is cholesterol made by our body.

This level stays largely constant as our body regulates the amount.

“Your genetic makeup – not diet – is the driving force behind cholesterol levels, says Dr. Nissen. “The body creates cholesterol in amounts much larger than what you can eat, so avoiding foods that are high in cholesterol won’t affect your blood cholesterol levels very much.”

This was stated by Dr Nissen, Chairman of the Department of Cardiovascular Medicine at the Cleveland Clinic.

Uses of cholesterol

Cholesterol has many uses in the human body. Some of them are:

  • Cholesterol is present in all cells of the body. The cell membrane that regulates what goes in and out of the cell is made up of cholesterol.
  • Cholesterol is used by the liver to make bile, helping digestion.
  • Many hormones and vitamin D are made from cholesterol.
Types of Cholesterol

Cholesterol is carried in the blood by lipoproteins. There are 3 main types:

  1. LDL – Low density lipoproteins or the “bad” cholesterol.
  2. HDL – High density lipoproteins or the “good” cholesterol.
  3. VLDL – Very low density lipoproteins that carry triglycerides.
Cholesterol is carried mainly by LDL. HDL is beneficial as it carries cholesterol back to the liver where it is excreted.

Why are we concerned about high cholesterol?

High cholesterol may cause build of fat in the walls of the arteries, which increases the risk of heart attack and stroke.

What are the causes of CVD?

Over many years the main risk factors of CVD have been diabetes, hypertension, high cholesterol stemming from a poor lifestyle. Sedentary life, a diet rich in saturated fats, smoking leading to obesity have all been contributing factors.

Research shows that cholesterol may not be to blame so much after all. Cholesterol-lowering drugs have been prescribed without much benefit.

A study published in the Journal of American College of Cardiology in 2017 showed that half of patients with normal LDL cholesterol had fat plaque in their arteries. None of these patients had any of the above risk factors.

I’m sure you know lots of people with a very healthy lifestyle who have had a heart attack or stroke.

Stress arising from negative life events is now an independent risk factor for CVD. Stress causes inflammation leading to fat build-up in arteries, in the presence of a normal cholesterol level and no other risk factors.

Uses of fats

Fats are essential as part of a healthy diet.

Fats are useful for our body:

  • Fats are a source of essential fatty acids which our body can’t make and needs from the diet.
  • Fats help carry fat-soluble vitamins that are essential for normal functioning of our body – Vitamin A, D and E.
  • Fats are a storehouse of energy. All carbohydrates and proteins that are unused are stored as fats. Fats can be burned to release energy when needed.
Types of fats

There are different types of fats:

Saturated fats

These should be limited to 30 g a day for men and 20 g a day for women. Saturated fats raise blood cholesterol levels.

Saturated fats are found in:

  • Fatty meat
  • Butter, ghee
  • Cheese, cream, and ice cream
  • Chocolate
  • Biscuits, cakes, and pastries
  • Palm oil and coconut oil
Trans fats

Trans fats raise blood cholesterol levels and should be limited.

They are found in meat, dairy and some partially hydrogenated vegetable oil.

Unsaturated fats

These help in lowering blood cholesterol.

They are a healthy alternative to saturated fats.

Monounsaturated fats

They are present in:

  • Avocados
  • Olive oil
  • Rapeseed oil
  • Nuts
Polyunstaurated fats

They are omega-3 and omega-6 oils:

  • Omega-6 oils are present in rapeseed oil, corn oil and sunflower oil and also nuts.
  • Omega-3 oils are present in oily fish like kippers, herrings, mackerel, sardines and salmon.
You need to avoid saturated fats and trans fats.

Foods that are rich in both cholesterol and saturated fats should be consumed in moderation. These are:

  • Full fatty dairy – milk, yoghurt, cheese.
  • Animal fats – butter, ghee.
  • Fatty meat
Food sources that are high in cholesterol but low in saturated and trans fats. These are:

  • Lean meat – mainly offal like kidney, liver, heart and tripe.
  • Shellfish – prawns, lobster, crab, and octopus.
  • Eggs
Eggs are affordable, rich in many nutrients and can contribute to a healthy diet.

Note however that people with diabetes should avoid cholesterol rich foods as there is still uncertainty if these foods can increase risk of CVD in them.

Familial hypercholesterolaemia

A genetic condition that causes raised cholesterol levels at a young age. There is reduced clearance of the ‘bad’ LDL cholesterol.

1 in 250 adults have this condition in the UK.

If you have this condition you are at increased risk of heart disaese and strokes at a young age.

Only 8 in 100 people with this disease are currently identified because there are usually no symptoms.

If you have a close relative with a heart attack at a very early age before the age of 50, it may be possible that you may have this condition.

Your GP would do a blood test where the cholesterol would be raised.

The good news is that it is treatable with medications called statins.

The problem is that most cases are not diagnosed.

If you do have this condition you would do well to avoid cholesterol rich food.

In summary

For most of us, eating a moderate amount of cholesterol is beneficial.

Limit saturated and trans fats.

Everything should be in moderation.

If you are diabetic or are known to have familial hypercholesterolaemia, you must take care to avoid cholesterol rich food.

Couple a healthy diet with a good exercise regime.

Eggs are among the most versatile of foods. I personally love eggs.

What is your favourite way of eating eggs?