Cholesterol.

The word probably brings up some negative connotations immediately when just reading it! This is understandable, due to the (typically) bad reputation cholesterol has – being linked to heart attacks, stroke and other cardiovascular diseases.

In this post, we dive into exactly how cholesterol is made, what cholesterol is, what the dangers of cholesterol are and what can we do to minimise our risk.

What is cholesterol?

Cholesterol is essentially a type of fat that is the main component of our cell membranes and other essential structures.

Many of us believe that cholesterol is made from just our diet, but in fact, this is a misconception.  A recent Harvard article [1] suggests that only 20-25% of the cholesterol in our bloodstream comes directly from our diet. The other 75-80% comes from raw materials already within our bodies such as fats, sugars and proteins.

Cholesterol is so vital to our everyday functioning that our liver and intestines will make an extra supply if we don’t consume enough through our food. 

 To put it into perspective, an adult who eats 200-300 milligrams (mg) a day (that’s the equivalent of one egg yolk!), will make up the additional 800 mg a day, mainly through the liver.

Cholesterol is a fat that the body packages up with other lipids into tiny protein-covered particles called lipoproteins (simply meaning lipid plus protein), which essentially move cholesterol and other fats throughout the body. If we were to hold a chunk of cholesterol in our hands it would look like a whitish-yellow powder that looks somewhat like the scrapings of a wax candle. 

So why the bad reputation? Well… too much cholesterol (especially the bad type!) can accumulate in the walls of the blood vessels causing all kinds of problems.

Let’s make sense of a cholesterol test!

Total cholesterol:
This is the sum of all the cholesterol in all the lipoprotein particles in your blood. It includes HDL, LDL and VLDL.

LDL cholesterol:
This is the dangerous blood lipoprotein particle.

HDL cholesterol:
HLD fights the plaque build-up in the heart’s arteries. The Framingham Heart Study [2] suggests that every 1 mg/dL increase in HDL cholesterol reduces the risk of cardiovascular disease by 2% to 3%.

For most people, if your total or LDL cholesterol is high your doctor may recommend a statin.

LDL particle size:

Not all LDL particles are created equally when it comes to heart disease. For example, not everyone with high LDL will develop heart disease. In fact, some people with normal LDL do. A possible explanation for this is the size and density of LDL particles. Small, denser LDL can more easily get into artery walls where it becomes oxidised, leading to the sequence of events that result in atherosclerosis. Larger LDL particles are more likely to bounce off the artery walls and not penetrate (these are therefore considered less dangerous).

If you’re particularly concerned about which type of LDL you have in your blood, advanced testing is now available (“Advanced lipoprotein testing”) which will give a more detailed view of not only the amount of cholesterol but also the size and number of particles in each category.

 

What is the relationship between cholesterol and inflammation?

As we’ve discussed in previous posts, inflammation plays a vital role in our immune system’s defence. However, inflammation can also initiate the process of plaque build-up in the arteries and thus can promote the formation of artery-blocking clots (these are the cause of most heart attacks and many strokes).

How does cholesterol travelling in the bloodstream cause a heart attack?

Here is the short explanation!
The plaque builds up within the artery wall, a fibrous cap tops the plaque, this plaque ruptures and a clot blocks the artery. Dangerous stuff.

What about cholesterol and food?

The 1960s onwards saw a great influx in the avoidance of cholesterol-rich foods (such as eggs, dairy and some types of seafood). However, with more recent research (for example 40 studies in 2015 in The American Journal of Clinical Nutrition as documented in the Harvard ‘Managing your cholesterol’ report [3]) there has been no clear evidence linking dietary cholesterol to a higher risk of coronary artery disease and stroke. Subsequently, there is a growing consensus among experts that there isn’t enough evidence to set limits on how much cholesterol we should consume. This is not to say we shouldn’t limit the amount of saturated fat and other nasties in our diet and opt for a diet rich in quality fruits, vegetables, fish and whole grains.

Lowering our cholesterol is an important factor in overall health. In fact, experts stress that the most important dietary change you can make to lower cholesterol numbers is to follow a healthy diet such as above.

This will help in two ways:

1. High fibre foods help reduce the cholesterol in our bloodstream by making dietary cholesterol harder to absorb from the gut.

2. The more you reach for the healthy option, the less you consume foods high in saturated fat and refined carbohydrates (both of which boost cholesterol levels). *This crowding out theory is a key foundation in the Sano programs!

 


 

The most important thing to consider in this space is understanding your cardiovascular risk, which encompasses more than just cholesterol levels.

 


 

There are some factors that you don’t have any control over that influence your cardiovascular risk, and some factors that you do have control over. It’s important to understand both!

Factors you don’t have control over are:

Being over 45 (men), being over 55 (women).

A family history: a father or brother who developed heart disease before age 50 to 55, or a mother or sister who developed it before age 60 to 65.

Being a premenopausal woman.


 

Although we can’t change these risk factors, it’s important to be aware of them and how at risk we might be.

 

Risk factors that are within your control:

High blood pressure: above 140/99 mm Hg.

Cholesterol-clogged arteries (atherosclerosis). This can take the form of chest pain with exertion or can have absolutely no symptoms at all.

Diabetes.

High triglycerides, high LDL cholesterol (or both).

Low HDL cholesterol.

Metabolic syndrome (which is a group of cardiovascular risk factors which can develop with another condition called pre-diabetes).

Being overweight (with a BMI of 25+) Click here for an online BMI calculator. 

Lifestyle factors such as smoking, lack of physical exercise, a diet high in saturated and trans fats, highly processed carbohydrates.

Chronic stress.

Social isolation, depression and/or anxiety.


 

Protective measures:

The number one recommendation is healthy eating and exercise. Changing these two habits can drastically alter our life’s course and health outcomes.

 

Some things to consider for a healthier life:

Lowering your total cholesterol by 10% can decrease heart attack by 20% to 30%

Walking (2 x weekly) can reduce your chances of dying early from cardiovascular disease by 45%

Cutting your sodium intake down by 1200mg per day can reduce the need for blood pressure treatment by half and can reduce deaths from stroke by 22%

Cholesterol and family histories:

Cholesterol isn’t always caused by poor lifestyle choices and habits, in some cases, genetic disorders (familial combined hyperlipidaemia and familial hypercholesterolemia being the most common) can be the culprit of high levels. If you have a genetic risk factor such as the above, this puts you at risk for early heart disease. These genetic disorders can be managed through diet and exercise and medication.

It isn’t just heart health that you’ll be benefiting when keeping cholesterol in check, a large study found that moderately elevated cholesterol levels in middle age increase the risk of developing dementia in old age!

How to test cholesterol:

A cholesterol test is known as a lipid profile or lipid panel. It measures total cholesterol, HDL cholesterol, LDL cholesterol and triglyceride levels. The most accurate results come from a fasting lipid profile. As mentioned previous, advanced testing is also available but not necessary for most.

When to test:

The American Academy for paediatrics recommends testing children aged 9-11 and once again when ages 17-21. This is because the process of atherosclerosis begins in childhood so we want to have a clear picture as early as possible. This includes identifying those with genetic conditions.
Early testing can prompt lifestyle modifications for new healthier habits.

 


 

For adults, there are a few things to keep in mind when going to the doctor for your cholesterol test (these could skew your results)

Have you had the flu or any illness shortly before the blood test?

Has your diet changed recently (in the weeks leading up to the test)? As alcohol and carbohydrate intake can raise triglycerides.

Did you fast before the test? Remember that if you didn’t, it’s best to be honest as your results will be incorrect.

Thinking has recently changed in regard to dietary changes to bring down cholesterol levels. Previous we thought that reducing the intake of dietary cholesterol and fat was the goal, however, now we encompass many different aspects of the healthy living (not just avoiding fat or cholesterol).

In a nutshell: favour the good fats, limit saturated fat, avoid sugary drinks and processed meat, fill up on whole foods, limit alcohol and focus on increasing your exercise to at least 2.5 hours of moderate-intensity exercise per week.

Finally, remember to practise mindfulness, get adequate, restful sleep and adopt other stress reduction habits. Stress plays a huge role in many diseases – this is something you can regulate and have control over.

 


 

[1] [3] Managing your cholesterol. A Harvard Medical School Special Health Report. Medical Editor Jorge Plutzky, MD. Report available for purchase at https://www.health.harvard.edu
[2] Framington Heart Study https://www.framinghamheartstudy.org/
In 1948, FHS scientists and participants embarked on an ambitious project to identify risk factors for heart disease. Today, the study remains a world-class epicentre for cutting-edge heart, brain, bone, and sleep research.