So many health conditions seem tied to or impacted by COVID-19, and cholesterol is no exception.

This article will provide more detail on this connection between cholesterol and COVID-19 and how one’s cholesterol levels may impact the risks of severe illness and complications from COVID-19.

Cholesterol is a waxy and fat-like substance in your body. It’s important for things like making cell membranes and producing certain hormones and vitamins.

Although cholesterol has important functions in the body, too much of it can be harmful. When there’s too much cholesterol in your blood, you usually have high cholesterol.

About cholesterol

Before starting, there are a few terms to go over regarding cholesterol:

  • Low-density lipoprotein cholesterol (LDL-C). LDL-C is often called “bad cholesterol.” This type of cholesterol contributes to cardiovascular disease by causing the buildup of plaque in your blood vessels.
  • High-density lipoprotein cholesterol (HDL-C). HDL-C is sometimes called “good cholesterol.” It helps flush LDL-C and plaque from your blood vessels, protecting you from cardiovascular disease.
  • Total cholesterol. Total cholesterol is the amount of LDL-C and HDL-C in the blood. It also involves the level of triglycerides, which are types of fats.
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Experts have observed changes in cholesterol levels in people with COVID-19. Specifically, levels of LDL-C, HDL-C, and total cholesterol become lower when a person has COVID-19.

According to a 2022 research article, various other viral, bacterial, and parasitic infections can lead to similar findings. Some examples of other viruses that can lead to altered cholesterol levels include:

Experts currently do not know how COVID-19 leads to lower cholesterol levels. Overall, experts believe that increases in inflammation during infection impact various pathways associated with cholesterol production, transport, and metabolism in the body.

With COVID-19, the extent of a drop in cholesterol levels can link with illness severity. A 2022 research review found that upon hospital admission, people with severe COVID-19 had lower levels of:

  • total cholesterol
  • LDL-C
  • HDL-C

According to researchers, HDL-C has anti-inflammatory and anti-thrombotic properties. So, it’s possible that a steep drop in HDL-C during COVID-19 may increase the risk of problems due to high levels of inflammation and blood clots.

The Centers for Disease Control and Prevention (CDC) estimates that about 38% of adults in the United States have high cholesterol. As such, you may be wondering if having high cholesterol increases your risk of developing COVID-19.

Currently, high cholesterol isn’t on the CDC’s list of conditions that increase the risk of COVID-19. However, several conditions that often happen along with high cholesterol include:

High cholesterol may increase your risk of developing COVID-19

A 2021 study found that higher body mass index and cholesterol were associated with COVID-19 cases and deaths.

The researchers suggested that this finding could be one reason why areas of the world with higher rates of obesity and high cholesterol have seen more COVID-19 cases and deaths.

Another 2021 study used data from the UK Biobank to look at the effect of cholesterol on COVID-19 susceptibility. After their analysis, the researchers found that having higher total cholesterol was actually associated with increased COVID-19 susceptibility.

How does high cholesterol increase your risk?

Cholesterol is present in the membranes of the cells in the body. As such, it’s possible that higher cholesterol increases susceptibility to COVID-19 by promoting viral entry into host cells.

A 2021 study investigated this idea. In a laboratory, experts loaded cell membranes with extra blood-derived cholesterol. Experts exposed the cell membranes to a test virus with the spike protein of SARS-CoV-2, the virus that causes COVID-19. The researchers saw that infection was higher in cholesterol-loaded cells.

They suggested that since the virus more effectively infected cells with higher cholesterol, this may add another reason why COVID-19 can be more severe in older adults, as they may be more likely to have underlying medical conditions like high cholesterol.

High HDL-C may protect against COVID-19

A 2022 study also looked at the effect of cholesterol levels on the risk of developing COVID-19. The researchers found that having high levels of HDL-C was associated with a lower risk of developing COVID-19.

Experts found the lowest level of risk in people that had high levels of HDL-C and low levels of LDL-C.

Unlike the other studies discussed, other types of cholesterol, like total cholesterol and LDL-C, weren’t independently associated with the risk of developing COVID-19.

Long COVID is a collection of symptoms that can last weeks, months, or even years after you have COVID-19. People with long COVID can experience a wide variety of symptoms. A few examples include:

Having COVID-19 can change cholesterol levels. But do some people continue to have altered cholesterol levels even after they recover from COVID-19?

A 2021 study followed up with people who had come to the hospital for COVID-19 after 3 to 6 months. Compared with their levels at admission, both LDL-C and HDL-C levels improved significantly at the follow-up appointment.

Having high cholesterol may actually increase your risk of long COVID as well as prolonged symptoms from other non-COVID illnesses. At least that’s according to a 2022 study.

The study involved people with a wide spectrum of COVID-19 severity, from asymptomatic individuals to those with long COVID. It also included people who tested negative for COVID-19, but had prolonged COVID-like symptoms.

Researchers looked at different blood biomarkers. Unhealthy lipid levels, including cholesterol, were associated with a longer symptom duration for those who had tested positive for COVID-19 and those with other similar illnesses.

COVID-19 vaccines can be great tools in preventing serious illness and death due to COVID-19. However, given the information about COVID-19 and cholesterol, you may be wondering if the COVID-19 vaccine can impact cholesterol levels as well.

There’s currently one 2021 case report of altered lipid levels after vaccination. In it, a person experienced high triglyceride levels after receiving their second dose of the Pfizer-BioNTech vaccine.

However, the catch is that this individual had an inheritable condition called familial hypercholesterolemia, in which levels of LDL-C greatly increase.

There’s currently no evidence that the COVID-19 vaccine impacts cholesterol levels in the general population.

COVID-19 can lead to a drop in cholesterol levels. The extent of this drop connects with illness severity. Most people’s cholesterol levels rise again after they recover.

Having high cholesterol may increase your risk of developing COVID-19 and of having long COVID. As such, consider taking measures to prevent illness, such as staying up to date on your COVID-19 vaccines.

High cholesterol can increase the risk of cardiovascular disease, which can have serious consequences, such as heart attack and stroke. If you have high cholesterol, work with your doctor to manage it.