What to know about cholesterol and heart disease

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Cholesterol is a waxy substance that the liver makes. People need cholesterol to support their health. It helps the body carry out important functions like digesting fatty foods and making hormones.

If a person has a total cholesterol level above 200 milligrams per deciliter (mg/dL), they have high cholesterol. Doctors measure a person’s total cholesterol level as the total of three substances in their bloodstream.

These substances are triglycerides and two kinds of lipoproteins:

• Low-density lipoproteins (LDL): These lipoproteins deliver cholesterol to cholesterol-dependent tissues through the bloodstream. High levels of LDLs may raise a person’s risk of heart-related health conditions.
• High-density lipoproteins (HDL): These lipoproteins absorb cholesterol in a person’s blood and carry it to the liver, which removes it from the body. High levels of HDLs may lower a person’s risk of heart-related health conditions.
• Triglycerides: These are a type of fat in the bloodstream and a source of energy for the body. A person’s body needs some triglycerides to support their health, but high triglycerides levels may raise their risk of heart-related health conditions.

The CDC indicates that a person’s liver makes all the blood cholesterol their body needs and suggests that people limit dietary cholesterol.

People with high cholesterol levels may be at increased risk of heart disease. However, recent research has indicated that the exact relationship between high cholesterol and heart disease may not be as clear as scientists previously thought.

If a person has too much LDL in their bloodstream, it may cause plaque buildup in their arteries, which can lead to a blockage. This blockage can reduce blood flow to and from a person’s heart. Over time, this can cause angina and heart attack.

High LDL levels may also raise a person’s risk of stroke and double a person’s heart disease risk.

Dietary cholesterol

However, in a 2019 study, researchers from the American Heart Association (AHA) questioned the relationship between dietary cholesterol and heart health. They analyzed a range of studies and found that there were mixed results.

For example, many observational studies found no significant association between dietary cholesterol or egg intake and cardiovascular disease (CVD).

However, a U.S.-based meta-analysis found that eating half an egg per day may increase the risk of CVD by 6%. Similarly, two studies found that egg consumption was associated with CVD risk in people with type 2 diabetes.

They concluded that specific dietary cholesterol targets are challenging to implement and guidelines focusing on overall dietary patterns are more likely to help people improve their diet and cardiovascular health.

The latest edition of the Dietary Guidelines for Americansno longer include a specific cholesterol diet limit. However, they do still recommend people limit consuming foods high in dietary cholesterol.

A 2018 review summarized research results focusing on links between dietary cholesterol and CVD. Researchers concluded there may be no link between heart disease risk and cholesterol in people considered healthy.

However, they also highlighted that foods rich in saturated and trans fats increase a person’s risk of cardiovascular disease. Dietary cholesterol is usually also present in these same foods. The researchers suggested that further studies into the relationship between dietary cholesterol and certain health conditions, like diabetes, are necessary.

To help lower cholesterol, doctors recommend a person’s diet include less saturated and trans fats. The AHA recommends people limit saturated fat to less than 6% of their daily calories. They also recommend a person minimize the amount of trans fat they consume.

Foods that may contain these fats include:

• red and processed meats
• whole milk dairy products
• fried food
• sugar-sweetened foods or beverages

Other ways people may lower their cholesterol levels include:

• exercising regularly
• quitting smoking if they smoke and avoiding secondhand smoke
• maintaining a moderate weight

Learn more about how to lower cholesterol without medication here.

High cholesterol levels do not typically cause any noticeable symptoms. Some people with high cholesterol may develop yellowish, cholesterol-rich, deposits on their skin, which doctors call xanthomas. However, other health conditions may also cause xanthomas.

Without regular testing, people may not know they have high cholesterol until they develop heart disease. However, heart disease often does not cause noticeable symptoms either.

Therefore, the CDC recommends that:

• people get regular cholesterol checks from an early age
• children have their cholesterol checked at least once between ages 9–11
• adolescents should have a check between ages 17–21
• healthy adults have their cholesterol checked every 4–6 years
• people with heart disease, diabetes, or a history of high cholesterol have their levels checked more often

If a person wishes to find out more about their cholesterol levels and individual risk for developing heart disease, they can take with a doctor to discuss their specific situation.

Many organizations like the CDC and AHA recommend managing cholesterol levels to help reduce the risk of developing heart disease. High LDL cholesterol levels in the bloodstream may increase the risk of heart disease and cardiovascular events like stroke.

However, scientists are still investigating the relationship between cholesterol and the risk of heart disease, particularly how dietary cholesterol may affect heart health.

People may want to consider modifying their diet, maintaining a moderate weight, and exercising regularly to help lower their cholesterol levels. They can also speak with a healthcare professional about regular cholesterol level checks and their individual risk of heart disease.