What is High Cholesterol?

prevention of heart disease Jul 17, 2023

What is High Cholesterol?

Written by Sandeep Singh, MD FACC  in Prevention of Heart Disease

Cholesterol is a substance in your blood that is produced by your liver but is also present in many of the foods we eat. Your body needs cholesterol in order for certain cells to function, but too much can be harmful. Most of the time, the reason behind our elevated cholesterol levels are the types and quantities of foods we eat. Occasionally it can be the result of a genetic condition that causes levels to rise.

The total cholesterol is a calculated number that is less important than the components of the cholesterol profile. The profile consists of LDL, HDL, and triglycerides.

LDL is the “bad” (or as I like to think of it as “Lousy”, L for Lousy) cholesterol which should be less than 100 optimally. Too high is if it over 160.

HDL is the “good” cholesterol (or “Helpful”, H for Helpful) which should be higher than 40. This is more genetically determined than the LDL or triglycerides. Low HDL is a risk factor for plaque buildup in your arteries.

Triglycerides come mostly from excess calories, often from too much sugar or carbohydrates. If you burn fewer calories than you consume it can lead to high triglycerides. The normal level of triglycerides is less than 150. Medications are often prescribed at levels consistently over 300.

Why do I have high Cholesterol?

  1. Sedentary Lifestyle – Regular aerobic exercise can improve LDL cholesterol and has the potential to raise HDL cholesterol. Of course, less calorie-burning leads to weight gain which can also raise triglycerides as well, in addition to elevated blood sugar.
  2. Weight Gain – The above sedentary lifestyle can lead to weight gain as can a poor diet that is high in sugar and carbohydrates. LDL cholesterol and triglycerides are prone to being higher with weight gain.
  3. Poor Dietary Choices – You have the power to decide what you put in your mouth. It’s a choice, plain and simple. Just because that box of cookies or cupcakes is sitting there in front of you doesn’t mean you have to actually have one. Your decision to have ice cream every night will come with a cost. A cost that you bear sole responsibility.
  4. Age – Getting older, slowing of your metabolism, will increase your risk for higher cholesterol levels
  5. Diabetes – Elevated blood sugars can be associated with elevated triglycerides. Diabetes and its elevated blood sugars increase plaque deposits into the arteries especially when the LDL is high and the HDL is low. Controlling diabetes is critical in keeping all forms of cholesterol under good control.
  6. Thyroid Disease – A very underactive thyroid (Hypothyroidism, Hashimoto’s Thyroiditis) can lead to a profound slowing of metabolism which can cause very elevated levels of cholesterol.

Are all foods with cholesterol bad for you?

Since the late 1960s, it has been thought that dietary cholesterol increases the risk of heart disease by depositing cholesterol directly into the arteries causing plaque buildup. The American Heart Association then went so far to include a limit on dietary cholesterol as a result.

It turns out that most foods with high levels of cholesterol also have high levels of saturated fat and it’s the saturated fat that is worse for you than the dietary cholesterol.

Additionally, the initial science in Nutrition research was highly flawed as it suggested that dietary cholesterol was the culprit for heart disease. The reality of this is that although cholesterol deposits into the arteries, it does not always stem from poor dietary choices, although it could.

Your Body May Make Too Much Cholesterol

Not everyone with high cholesterol eats poorly, nor is overweight. There are some families in which all members share the same gene that causes too much cholesterol to be produced.

One family that I care for has every single sibling and parent with cholesterol levels so high that each has had a coronary event and takes a medication to lower cholesterol. One of them is even a marathon runner who had his first coronary stent at the age of 30 and takes TWO cholesterol medications despite being healthier and more active than most.

Cholesterol is transported around the body in packets referred to as lipoproteins. Since its a waxy substance (kind of like a paste) it can’t dissolve into the bloodstream so it needs to be carried in these lipoprotein carrier molecules. Sometimes, there are factors at play beyond your control as to why there may be too much cholesterol in your bloodstream.

There are genetic reasons as to why someone can have very high cholesterol. The most common reason is a condition called Familial Hypercholesterolemia (HF). This can be the result of inheriting either one or two defective genes from your parents. If you have only one defective gene, then you have heterozygous FH and your cholesterol numbers can be in the 300+ range.

Not even eating cardboard and grass will lower these numbers if you have FH unfortunately. You will need help.

What’s worse is when you have two defective genes. This is called homozygous FH and your cholesterol numbers are even HIGHER. Like cholesterol levels in the 500+ range, as high as over 1000!  These patients may need a more aggressive form of therapy called LDL apheresis. It’s like dialysis (which is done in patients with advanced kidney disease whose kidneys no longer function) though less often, as in once every 1-2 weeks. It’s pretty effective and lowers LDL by up to 80%.

What Can High Cholesterol Do To My Body?

High cholesterol can cause deposits into your arteries that supply your brain, heart, kidneys, legs, and intestines. This can lead to poor blood flow into any of these organ systems. The most concerning would be the arteries that supply your heart and brain.

This is a schematic of what cholesterol deposits into an artery look like…

Blocked arteries that limit blood flow to your organs can lead to the following conditions:


Organ to which there is a lack of blood flow Resulting Problem
Brain Stroke, Mini Stroke, Dementia
Heart Heart Attack, Heart Failure, Chest Pain, Needing a stent or coronary bypass
Kidneys Kidney (Renal) Failure, Needing Dialysis
Legs Painful walking (Claudication), Loss of Limb (amputation)
Intestines Abdominal pain, Weight Loss, Loss of bowel function or needing urgent bowel surgery, death

Being aware of your cholesterol numbers can help lessen the risk of the above if appropriately treated.

How is high cholesterol treated?

The first intervention when it comes to high cholesterol is always lifestyle optimization.

The two-pronged approach to lifestyle changes are dietary intervention and exercise.

“D-I-E-T” is a four-letter word. It implies you’re going to on it, then go off it. You must make changes for the better that are sustainable.

What foods should you eat? No one can tell you that. We all have so many likes and dislikes that it’s impossible to come up with a meal plan that fits all palates. The general dietary recommendations from most authorities would be WFPB. That stands for Whole Food, Plant-Based. The more what you are putting in your mouth looks like something that exists in nature, the healthier it is. Most animals that humans eat, look nothing like they exist in nature, which means they’re all processed. Coldwater (Ocean bred) fish are probably the closest to a whole food you will get in the meat category.

The Mediterranean diet is also a food plan that has been well studied and shown to reduce cholesterol as well as the risk of developing heart disease. It is a term that refers to the dietary habits of countries that border the Mediterranean Sea. The common components to their diets included the following:

  • Vegetables, Fruits, whole grains, beans, nuts, seeds, potatoes
  • Olive Oil as the primary source of fat
  • Dairy products, eggs, poultry, and fish in small amounts

The American Heart Association recommends the Mediterranean diet as a way to lower the risk of heart attack and stroke. If you want to read about more details regarding this food plan, Harvard Health provides a practical guide.  For those interested in seeing the original paper cited in the New England Journal of Medicine, a more detailed account of the trial and results can be found.

The other side of the coin of lifestyle optimization is exercise.

A sedentary lifestyle is one of the main risk factors for heart disease and stroke. The others include high blood pressure, elevated cholesterol, smoking, and obesity.

The current recommendation by the American College of Sports Medicine and the CDC is 30 minutes of aerobic activity on most, if not all, days of the week. Exercise has been shown to reduce the risk of heart disease and stroke.

Exercise can reduce cholesterol levels, reduce blood pressure, improve brain health, lessen the risk of dementia, reduce weight, and lessen the risk of osteoporotic fractures. A nice overview of exercise and cardiovascular health can be found published by the American Heart Association.

Questions to Ask Your Doctor About Your Cholesterol

Now that I know I have high cholesterol….

What exactly are my cholesterol numbers?

Total cholesterol =



Triglycerides =

What lifestyle changes do I need to make to help improve my cholesterol levels and heart health?

Do I need cholesterol medicine now and if not, at what levels would you consider starting them for me?

What are the possible side effects of the medicine and how likely is it that I will be affected?

When do I have to do my next blood test to check my cholesterol?

A nice video example as to how cholesterol can buildup into the arterial wall can be seen below, published by the National Institutes of Health, National Heart, Lung, and Blood Institute.