What is cholesterol?
Cholesterol is a waxy, fat-like substance that circulates in the bloodstream. It helps make new cells, hormones, and substances that help digest food.
Two sources produce cholesterol: our body and our diet. The liver creates the amount of cholesterol needed for healthy function. Dietary cholesterol comes from meat, poultry, and dairy. These foods are high in saturated and trans fats that cause your liver to make more cholesterol than needed.
Too much cholesterol increases the risk of cardiovascular diseases, such as heart disease and stroke.
What are the types of cholesterol?
Cholesterol is carried through your blood, attached to proteins. This combination of proteins and cholesterol is called a lipoprotein. The 2 types of cholesterol are named based on lipoproteins that carry it to and from cells. One is low-density lipoprotein or LDL, and the other is high-density lipoprotein or HDL.
LDL cholesterol
LDL (bad) cholesterol joins with fats and other substances to build up in your arteries’ inner walls, creating a thick, hardened plaque. Arteries become clogged and narrowed, reducing blood flow.
The arteries themselves then become less flexible – a condition known as atherosclerosis. This condition may result in chest pain (angina) and other symptoms of coronary artery disease.
If the buildup of these plaque deposits ruptures, a blood clot may form at the rupture site. This could block the flow of blood, or break free and plug an artery elsewhere in the body. If blood flow to part of your heart stops, you can have a heart attack. If blood flow to part of your brain stops, a stroke occurs.
With LDL, a lower number is better. A diet high in saturated and trans fat is unhealthy because it tends to raise LDL cholesterol levels.
HDL cholesterol
The “good” kind of cholesterol is high-density lipoprotein (HDL). HDL picks up excess LDL cholesterol and takes it back to your liver so it can be broken down and passed from the body. HDL may also remove cholesterol from plaque in the arteries. In this way, a healthy HDL-cholesterol level may protect against heart attack and stroke.
Another measurement considered when your doctor orders your cholesterol checked is triglyceride level. Adding HDL and LDL cholesterol levels, plus 20% of the triglyceride level, provides the total blood cholesterol number.
Triglycerides
Triglycerides are a type of fat. People with high triglycerides often have a high overall cholesterol level, with high LDL (bad) and low HDL (good). Genetics, type 2 diabetes, smoking, obesity, and a sedentary lifestyle can lower HDL levels.
High cholesterol can be genetically inherited, but it is often the result of unhealthy lifestyle choices, making it preventable and treatable. High cholesterol is one of the major controllable risk factors for coronary heart disease, heart attack, and stroke. Other risk factors, such as smoking, high blood pressure, and diabetes, further increase the risk.
What causes high cholesterol?
Factors you can control contribute to high LDL and low HDL cholesterol. Factors beyond your control might play a role, too.
Controllable factors that can increase the level of LDL cholesterols include:
- Poor diet: Eating saturated fats, found in animal products, and trans fats, found in baked goods and other processed foods, can raise your cholesterol level. High blood sugar, which can result from dietary choices, contributes to higher levels of dangerous cholesterol called very-low-density lipoprotein (VLDL) and lower HDL cholesterol. High blood sugar also damages the lining of your arteries.
- Obesity: Having a body mass index (BMI) of 30 or greater puts you at high cholesterol risk.
- Lack of exercise: Exercise helps boost your body’s HDL cholesterol while increasing the size of the particles that make up the LDL cholesterol, which makes it less harmful.
- Tobacco use: Smoking damages your blood vessels’ walls, making them more prone to accumulate fatty deposits.
Uncontrollable factors include:
- Genetics: Your genetic makeup might prevent cells from effectively removing LDL cholesterol from your blood or cause overproduction of cholesterol in your liver.
- Age: As you age, your body chemistry changes. Your liver becomes less able to remove LDL cholesterol, and the risk of high cholesterol climbs.
How to lower cholesterol
Lifestyle can reduce your cholesterol levels and prevent high cholesterol in the first place. Here are the most critical steps to take:
1. Eliminate non-heart-healthy foods.
Changes in your diet can reduce cholesterol and improve your heart health. Reduce intake of red meat and full-fat
dairy products like whole milk, cream, ice cream, butter, and cheese (full of saturated fats).
Eliminate trans fats, listed on food labels as “partially hydrogenated vegetable oil,” often used in margarine and store-bought baked goods.
Reduce intake of tropical oils such as coconut and palm oils (also saturated fat). Reduce the consumption of fried foods and baked goods, especially those with a lot of sodium and/or sugar.