What Are Lipids?

Preventing cardiovascular disease means keeping your heart and blood vessels healthy. To check your cardiovascular health, your doctor may order a lipid panel.

Your doctor may call it a lipoprotein panel or cholesterol screening. Here’s what all those terms mean for your heart and blood vessel health.

What Are Lipids?

Lipids are fatty, oily, or waxy compounds that your body needs in small amounts.

Examples of lipids

Lipids consist of:

  • Fats, including saturated fat, unsaturated fat, and trans fat.
  • Phospholipids.
  • Sterols.
  • Triglycerides, a type of oily fat in your blood.
  • Waxes.

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Lipid Functions

Lipids function in some of your body’s most important processes. They are a necessary part of cell membranes.

What fats do

Fats found in food are sources of energy. Fats add flavor to food and can help you feel fuller. They also help your body absorb vitamins A, D, E, and K.

Glycerol and fatty acids make up fats. These fatty acids join together in groups of three to form triglycerides.

What phospholipids do

Phospholipids provide cell protection and act as a barrier to certain molecules. They decide which molecules can enter or exit the cell.

What sterols do

Sterols are also part of plant and animal cell membranes. In human membranes, the most important sterol is cholesterol. You can also find sterols, called stigmasterol, in plant membranes.

Cholesterol isn’t only in the foods you eat. Cholesterol is also a waxy, fat-like substance found naturally in your bloodstream and cells. Your liver makes all the cholesterol your body needs to keep you healthy.

Cholesterol plays several important roles in your body:

  • It helps make new cells.
  • It helps make substances that digest food.
  • It helps make other hormones, including cortisol, estrogen, and testosterone.

But sometimes you can have too much cholesterol in your body. And the foods you eat can add to your cholesterol levels. When you have too much cholesterol, it can increase your risk of heart and blood vessel diseases.

What triglycerides do

The most common type of fat in your body, triglycerides have several functions. They:

  • Help your body absorb fat-soluble vitamins.
  • Provide insulation to cells.
  • Store energy.

Your body makes triglycerides. It also comes from the food you eat. But too much triglycerides in your blood puts you at risk of heart and blood vessel disease.

Triglycerides can build up in your artery walls, forming a hard, thick substance called plaque. When this happens, it can restrict blood flow or cause a blood clot. Plaque can also break off and travel to your bloodstream, causing a heart attack or stroke.

What waxes do

Waxes also provide protection for cell membranes in plants and people. Earwax is an example of protective wax in people. It helps protect the skin of your ear canal.

What Are Lipoproteins?

Lipoproteins are particles needed to transport or carry lipids in water. Your body requires different types of lipoproteins for different phases of lipid transport.

Examples of lipoproteins include:

  • Chylomicrons.
  • Very-low-density lipoproteins (VLDL).
  • Intermediate-density lipoproteins (IDL).
  • Low-density lipoproteins (LDL).
  • High-density lipoproteins (HDL).

What lipoproteins do

Chylomicrons are large triglyceride-rich particles made in the small intestine. They help carry dietary cholesterol and triglycerides to your liver and tissues. They help your body absorb dietary fat and fat-soluble vitamins.

Your liver also makes VLDL, which is rich in triglycerides. Muscle and adipose tissue remove triglycerides from VLDL to create cholesterol-rich IDL particles. VLDL and IDL particles form cholesterol-rich LDL particles.

What is LDL cholesterol?

LDL, also called “bad” cholesterol, carries most of the cholesterol in your blood. Having too much LDL increases your risk of cardiovascular disease. LDL can join other fats and substances in your artery walls, building up and creating plaque.

What is HDL cholesterol?

HDL particles have both cholesterol and phospholipids. They carry LDL away from tissues to your liver and remove it from your body. They call HDL cholesterol “good cholesterol.” It helps reduce cholesterol blockages in your arteries.

What Is a Lipid Panel?

A lipid panel is one of several important health screenings you need. It is a blood test your doctor uses to measure:

  • HDL, or “good” cholesterol. Higher is better.
  • LDL, or “bad” cholesterol. Lower is better.
  • Total cholesterol. Lower is better.
  • Triglycerides. Lower is better.

Doctors measure total cholesterol readings in milligrams per deciliter (mg/dL).

Your results will fall into one of these categories:

  • 200 mg/dL or lower = normal
  • 200 – 239 mg/dL = borderline high
  • 240 mg/dL or higher = high

Getting ready for a lipid panel

Your doctor may order a fasting or non-fasting lipid panel. For fasting screenings, you need to stop eating or drinking anything but water 9 to 12 hours before.

When should you get cholesterol screening?

Lipid panels are often part of a regular checkup, but you don’t need one every year. When you get these blood tests will depend on your age, family medical history, and other risk factors for cardiovascular disease.

You should not wait until you are an adult to get your cholesterol checked. Screening should start in childhood. Catching and managing cholesterol early can help prevent damage to your heart and arteries.

For people without other risk factors or a family history of heart disease, the American Heart Association recommends the following:

  • Between ages 9 and 11: Children should get an initial cholesterol screening.
  • Between ages 17 and 21: Teens and young adults should get another screening.
  • After age 20: Your doctor or healthcare provider should check your cholesterol every four to six years as long as your risk remains low.

You may need cholesterol screenings more often if you:

Other Lipid Tests

Some risk for heart and blood vessel disease comes from genes you inherit from your parents. To find out whether you have these genes, your doctor may order a lipoprotein-a or Lp(a) test.

What is an Lp (a) test?

High Lp(a) levels put you at high risk of cardiovascular disease, even if your other cholesterol levels are healthy.

Your Lp(a) levels don’t change as you get older. It comes from your inherited genes.

An Lp(a) test is not part of a routine lipid panel. But your doctor may order one if:

  • You have a family history of early heart disease, such as a heart attack.
  • You don’t know your family medical history.

With high Lp(a) levels, your doctor may prescribe statins to prevent heart disease, even if your other cholesterol levels are healthy.

National Library of Medicine. StatPearls. Biochemistry, Lipids. Link.

National Library of Medicine. Fats and Other Lipids. Link.

Nemours Kids Health. Fatty Acids. Definition. Link.

Nutrition and Metabolism. Fat-soluble vitamins: updated review of their role and orchestration in human nutrition throughout life cycle with sex differences. 2022. Link.

National Institutes of Health. Blood Cholesterol Diagnosis. Link.

American Heart Association. My Cholesterol Guide. Link.

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