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HDL vs LDL: Understanding good and bad cholesterol

What is cholesterol?

Cholesterol generally comes up in discussions about health, especially heart heath. It is also often tested during annual health screenings. Knowing cholesterol levels is important, but why?

The body needs cholesterol to build cells, but excess cholesterol can cause problems. Cholesterol is made in the liver, but it can also come from animal-based foods such as meat, poultry, and full-fat dairy products. These foods can also be high in saturated and trans fats, which cause the liver to make more cholesterol than the body needs. There are two types of cholesterol measures: LDL cholesterol and HDL cholesterol.

Types of cholesterol - the good and the bad

Cholesterol travels through the blood on lipoproteins. There are two types of lipoproteins: Low-density lipoproteins (LDL) and high-density lipoproteins (HDL).

  • LDL cholesterol is known as “bad cholesterol,” and it transports cholesterol particles through the body.
  • Excess LDL cholesterol can build up in artery walls and make them hard and narrow, which can increase your risk of heart attack or stroke.
  • HDL cholesterol is known as “good cholesterol,” and it can pick up excess cholesterol and carry it to the liver, where it is broken down.
  • A high level of HDL cholesterol is associated with a decreased risk of heart disease.

What are healthy cholesterol levels?

High cholesterol can only be detected through a blood test; it has no symptoms of its own. In biometric screening results, cholesterol will be measured in milligrams per deciliter of blood (mg/dL).1

A healthy level of LDL cholesterol for both males and females is less than 130 mg/dL.2 Most LDL cholesterol results are calculated from a formula based on measurements of total cholesterol and triglycerides. Triglycerides are sensitive to food and drink, so if a participant does not fast prior to screening, their triglyceride result, and thus their LDL cholesterol result, may not be an accurate representation of health status. In some cases, when a non-fasting screening is ordered or when triglycerides are very high, direct LDL cholesterol is measured instead of using triglycerides to calculate LDL. A direct LDL is a more accurate measurement for employer screenings that do not require fasting.

Unlike LDL cholesterol, higher levels of HDL cholesterol are more optimal. A healthy level of HDL cholesterol for males is greater than 40 mg/dL4, while a healthy level for females is greater than 50 mg/dL.3 Many doctors use HDL cholesterol levels to predict lifetime risk of a heart attack or stroke.

What affects cholesterol levels?

It is possible to control some of the risk factors related to high cholesterol by eating a healthy diet and getting physical activity. However, your genetics can also contribute to your cholesterol risk.

  • A diet high in saturated and trans fats is linked to high LDL cholesterol levels.2
  • Typically, choosing a heart-healthy diet, including low-fat proteins and a variety of fruits and vegetables, as well as exercising regularly, can help to reduce LDL cholesterol.
  • HDL cholesterol levels can be raised by following a healthy diet, eliminating tobacco exposure, and avoiding excessive drinking.
  • There is also a strong correlation between regular exercise and high HDL cholesterol. The ideal level of exercise to increase HDL cholesterol levels is moderate-intensity activity 3 to 5 times per week (the equivalent of burning about 1,200 to 1,600 kcal weekly).4

How can employers encourage cholesterol checks?

93 million US adults have total cholesterol levels higher than 200 mg/dL which increases their risk for heart disease and stroke.5 What’s more, heart disease and stroke are the reasons behind one-third of all deaths in the US and $1 trillion in healthcare costs and lost productivity.6 The best way to help employees measure cholesterol levels is to provide yearly biometric screenings that, along with health intervention solutions, help reduce heart disease risk.

Download the cholesterol infographic to learn more about the types of cholesterol

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1. Value according to the American Heart Association.

2. “What Your Cholesterol Levels Mean.” American Heart Association. 2016.

3. Quest Diagnostics Health & Wellness uses a different range for HDL cholesterol for females as per Riker, et al, JAMA, July 20, 2005 (294: 3): pgs. 326 – 333.

4. “Physical activity and high density lipoprotein cholesterol levels: what is the relationship?” Sports Medicine, Nov. 1999 (28: 5): pgs 307 – 314.

5. High Cholesterol Facts. September 8, 2020

6. American Heart Association. Cardiovascular diseases affect employers.