Lipoproteins, including cholesterol, are often misunderstood. Many people assume that all cholesterol is bad and that high-cholesterol foods negatively impact health, but this is not always true.
People with high cholesterol struggle to find natural ways to increase levels of “good” cholesterol and decrease levels of “bad” cholesterol.
This article explains what lipoproteins are, how cholesterol affects health, and how to get and maintain healthful cholesterol levels.
Lipoproteins are spherical particles that carry lipids, or fats, in the body. These particles contain both lipids and proteins.
People get lipids from their diet. The body can also make its own lipids, which are known as endogenous lipids.
Cholesterol is a type of lipid that people can get from food, but the liver makes all the cholesterol that the body needs, for example, to create bile acids and make hormones.
Lipids, including cholesterol and triglycerides, are packaged in lipoproteins. This allows them to travel through the bloodstream and be used throughout the body.
Experts categorize lipoproteins according to their size, biological role, and what they contain.
There are 7 classes of lipoprotein particles, but the four major types are:
- Chylomicrons: These are large, triglyceride-rich lipoproteins that intestinal cells produce from dietary fats.
- Very low-density lipoproteins (VLDLs): The liver produces these triglyceride-rich particles, which are smaller than chylomicrons, though their size can vary.
- Low-density lipoproteins (LDLs): These are the main carrier of cholesterol in the blood, and they deliver to cholesterol-dependent tissues, such as the adrenal glands and the gonads.
- High-density lipoproteins (HDLs): These play an essential role in reverse cholesterol transport — bringing cholesterol from other tissues to the liver.
Lipoproteins play essential roles in the body — specifically in:
- the absorption and transport of lipids in the small intestine
- transporting lipids from the liver to tissues
- transferring lipids from tissues to the liver, also known as reverse cholesterol transport
During reverse cholesterol transport, the body removes excess cholesterol from the tissues and brings it back to the liver. Then, the gallbladder may remove it from the body, or it may be redistributed.
When people discuss the types of lipoprotein, they generally say that some types are bad for health, while others protect against disease.
LDL and VLDL cholesterol are linked with the development of atherosclerosis, a process in which plaque builds in the arteries. Atherosclerosis is the main underlying cause of heart attacks, stroke, and heart disease.
HDLs help remove excess cholesterol from the body and protect against atherosclerosis.
Maintaining optimal levels of triglycerides and HDL, LDL, and VLDL cholesterol is essential to health and helps protect against disease development. Having elevated levels of triglycerides or LDL or VLDL cholesterol and low levels of HDL cholesterol can increase disease risk and negatively impact overall health.
What’s more, lipoprotein size matters when it comes to disease risk. For example, small, dense LDL particles are more likely to cause atherosclerosis than larger LDL particles.
This is because small, dense LDL particles last longer in circulation, more easily enter and adhere to arteries, and are more susceptible to oxidation — a process in which LDLs interact with unstable molecules called free radicals, leading to damage.
Also, certain conditions and lifestyle choices are linked with higher triglyceride and LDL levels and lower HDL levels. These include:
Additionally, genetic factors can lead to high cholesterol and triglyceride levels. For instance, people with familial hypercholesterolemia have mutations to the LDL receptor gene, which can cause elevated LDL cholesterol levels.
Although having high cholesterol and triglyceride levels is considered a risk factor for developing heart disease, it is important to remember that blood lipid levels are just one of many factors contributing to heart disease risk.
Plus, while some people are genetically more likely to have high cholesterol and triglyceride levels, most people’s levels are primarily affected by diet and lifestyle choices.
However, contrary to popular belief, high-cholesterol foods do not significantly impact most people’s blood cholesterol levels.
This is because the body regulates endogenous cholesterol production based on dietary cholesterol intake, meaning that the body makes less cholesterol when the dietary intake is high.
Although around 25% of the population, a group known as hyper-responders, are more sensitive to dietary cholesterol, due to genetic factors, research shows that, generally, the consumption of high-cholesterol foods, including eggs, does not seem to increase heart disease risk, even in hyper-responders.
People with high cholesterol or triglyceride levels may wonder what they can do to bring them down.
Fortunately, research shows that a number of diet and lifestyle modifications can significantly impact lipoprotein levels.
For reference, here are current recommendations for optimal blood lipid levels:
- triglycerides: under 150 milligrams per deciliter (mg/dl)
- LDL cholesterol: under 100 mg/dl
- HDL cholesterol: at least 60 mg/dl
Below are some evidence-based ways to reach and maintain these optimal levels.
- Eat more fiber: A fiber-rich diet can reduce LDL cholesterol and triglyceride levels by 5–10%. Some high-fiber foods include beans, fruits, nuts, seeds, and whole grains.
- Reduce excess body fat: Doing so can improve HDL levels, decrease LDL and triglyceride levels, and help cut heart disease risk.
- Increasing physical activity: This is an excellent way to lower blood lipid levels and boost HDL levels. Plus, studies have shown that aerobic exercise can reduce the concentration of small, dense LDL particles, which can be more dangerous.
- Limit added sugar and processed foods: Diets high in added sugar and processed foods are linked to unhealthy lipoprotein levels. Added sugar, especially in beverages, is significantly linked with high triglyceride levels.
- Cut out processed meats: Consuming processed meats, including bacon and sausage, is associated with unhealthy blood lipid levels.
- Choose healthy fats: Favoring nutritious sources of fats, including those from avocados, olive oil, nuts, and seeds, may help improve blood lipid levels and decrease heart disease risk.
- Consider taking an omega-3 supplement: Numerous studies have shown that this type of supplement can reduce LDL and triglyceride levels and increase HDL levels. Regularly eating omega-3-rich fish, such as salmon, can also benefit blood lipid levels.
Although these tips are appropriate and healthy for most people, anyone with high blood lipid levels or low HDL cholesterol levels should work with a qualified healthcare professional to come up with a tailored plan that suits their specific needs.
Plus, some people require medication to keep their levels within a healthy range.
It is also important to speak with a healthcare provider before starting any new supplement to make sure that it is safe and appropriate.
Lipoproteins play essential roles in the body and are important to overall health. Maintaining healthy lipoprotein levels is key.
People with high cholesterol or triglyceride levels, or those who need to boost their HDL levels, may benefit from taking the steps listed above.
However, it is a good idea to consult a healthcare provider for specific advice.