Here’s How Inflammation and Cholesterol Impact Heart Health

Cholesterol has long been seen as a key culprit in heart disease, an umbrella term for the conditions that affect the heart and blood vessels. But in addition to cholesterol, many other factors contribute to heart diseases, such as blood pressure, blood sugar, and weight.

So, what is cholesterol, and why does it have such a significant impact on heart health? Here's what you should know about the relationship between cholesterol, inflammation, and heart disease. 

What Is Cholesterol?

The liver produces cholesterol, a waxy, fatty substance. But cholesterol also occurs in foods. Cholesterol comes in two main types: low-density lipoprotein (LDL), or "bad," cholesterol, and high-density lipoprotein (HDL), or "good," cholesterol. 

Cholesterol in the blood is essential for maintaining good health because it makes hormones and breaks down fatty foods, among other vital functions.

But too much cholesterol can be a bad thing. That's because high LDL and low HDL cholesterol levels put people at risk of heart diseases, including heart attack and stroke.

Measuring Cholesterol

To measure cholesterol levels, a healthcare provider will have you take a lipoprotein panel (or lipid panel), which is a blood test. Before you take the test, you need to fast for nine to 12 hours. You can have only water, no food or other beverages.

The lipoprotein panel will measure your total, LDL, HDL, and non-HDL cholesterol. It will also measure your triglycerides, another type of fat in your blood that can increase your risk of heart disease.

For adults, measured in milligrams per deciliter, healthy levels are:

• Total cholesterol: 125 to 200 
• LDL cholesterol: Less than 100 
• HDL cholesterol: 50 or higher and 40 or higher for women and men, respectively 
• Non-HDL cholesterol: Less than 130  
• Triglycerides: Less than 150 

Regarding when you should receive the test, there are different recommendations, which include:

• Starting at about 10 years, you should receive the test every five years.
• For men and women, people aged 45 to 65 years or 55 to 65 years, respectively, should receive the test every one to two years.
• People with high-risk factors and a family history of high cholesterol or heart disease should receive the test more often.

What Is Inflammation?

Research has found that inflammation is a primary source of chronic diseases—including heart disease. Inflammation is the flood of white blood cells and chemicals your immune system unleashes to ward off damage or infection. 

Cholesterol wouldn't be nearly as dangerous without inflammation, which brings about atherosclerosis. Atherosclerosis is the hardening of the arteries that occurs when LDL cholesterol builds up.

Inflammation and Cholesterol

Excess LDL cholesterol seeps into the artery's inner wall when blood cholesterol levels rise, triggering an inflammatory response. That response speeds up cholesterol accumulation in the artery wall.

In turn, more inflammation occurs. That process repeats until the deposited cholesterol hardens into a plaque. That plaque can rupture and lead to blood clots that cause heart attacks and strokes.

Additionally, some evidence suggests that inflammation links to many diseases and conditions that affect the heart and brain. 

"Inflammation is the common denominator in nearly all of the diseases we deal with," James H. O'Keefe, MD, a cardiologist and medical director of the Charles and Barbara Duboc Cardio Health & Wellness Center at Saint Luke's Mid America Heart Institute, told Health. "Heart disease, diabetes, dementia. They're all tied to inappropriate, low-grade, chronic inflammation."

Measuring Inflammation

The role of inflammation in atherosclerosis doesn't diminish the importance of cholesterol. You still have to keep your LDL cholesterol level low and your HDL cholesterol level high. 

But the link between inflammation and heart disease presents another way to anticipate heart disease. Here's what you should know about measuring inflammation.

C-Reactive Protein (CRP)

Cells in your liver release CRP in response to inflammation. CRP may be more effective than cholesterol in gauging the risk of heart attack and other heart-related conditions

In fact, some evidence suggests that CRP is one of the most valuable biological markers of atherosclerosis. Other studies have confirmed CRP's predictive role in developing heart disease and other inflammation-related conditions.

CRP Test

In 1998, the Food and Drug Administration approved a CRP test designed to measure the risk of heart disease, known as a high-sensitivity C-reactive protein (hsCRP) assay.

The test became nearly as routine as the lipoprotein panel. Some healthcare providers even administer the hsCRP test, which requires a simple blood workup, as part of annual physical exams. Still, the importance of CRP is a matter of dispute.

"One of the issues and controversies regarding CRP as a risk factor for cardiovascular disease has been whether it is simply a marker or whether the higher levels actually cause heart attack and stroke," Alexander Reiner, MD, a research professor of epidemiology at the University of Washington School of Public Health, told Health. "It's very difficult to tease that out. It can work both ways, and my guess is, it probably does." 

Genetics and CRP Levels

Dr. Reiner is among a group of researchers across the United States who look at genes to establish a link between inflammatory markers and the risk of heart disease. Those researchers identify genetic variations that predict CRP levels. They also look at variations that predict heart attacks and other heart-related conditions. 

But as of January 2023, those researchers have not found a single gene that indicates both. Theoretically, that gene would show the link between CRP and cardiovascular disease if it exists. 

"That would be the holy grail," added Dr. Reiner.

Reducing Inflammation

So, the exact role of inflammatory markers is unclear. But suppose your CRP test uncovers high levels of CRP, which is over three milligrams per liter. In that case, you should assess your heart disease risk, even if you have normal cholesterol. For instance, a healthcare provider may start you on aspirin therapy or, most likely, a cholesterol-lowering medication.

Medications

Research has shown that those medications, also called statins, reduce inflammation and lower inflammatory markers like CRP levels. Even though some statins have more potent effects on inflammation than others, they're effective treatments for inflammation.

While people frequently use statins, other studies have found other medications, like colchicine, that may also reduce inflammation and CRP levels.

Lifestyle Changes

But medications aren't a silver bullet. You may be able to modify CRP levels through lifestyle changes. Research has found that CRP levels may decrease with the following lifestyle changes:

• Quitting smoking
• Increasing physical activity
• Following a healthy diet
• Maintaining a healthy body weight

Diet and Inflammation

In particular, a poor diet can aggravate inflammation. High-calorie and high-fat meals may cause a sudden spike in CRP and other inflammatory markers.

"The inflammation is due to a fundamental problem of using the wrong fuel for the engine," explained Dr. O'Keefe. "We're not designed to burn this stuff. And when we do, it throws off all these inflammatory by-products." 

A restricted-calorie diet, similar to the Mediterranean diet, may help keep inflammation to a minimum, said Dr. O'Keefe. The Mediterranean diet, for example, focuses on foods like:

• Small amounts of lean meat and chicken
• Whole grains
• Fresh fruits and vegetables
• Nuts
• Legumes
• High-fiber foods
• Fish and other seafood
• Olive oil 

"The key to restoring good health to America is getting people to tune in to the connection between the dynamic, hour-to-hour nature of inflammation and their general health and well-being—of their heart, their brain, their blood," noted Dr. O'Keefe. "From a health standpoint, nothing is more important than keeping those inflammation levels down."

Will Inflammation Markers Replace Lipoprotein Panels?

Not everyone is convinced that inflammation is the next big thing in heart healthcare. At the same time, inflammation markers may prove helpful to test and treat. 

But those markers will not like take the place of cholesterol, Alan Daugherty, PhD, director of the Saha Cardiovascular Research Center at the University of Kentucky College of Medicine, told Health.

"If you gave [healthcare providers] a choice between doing a test for cholesterol or CRP, I'm fairly certain that more than 90% would take the LDL cholesterol measurement," said Daugherty. "I very much doubt it will ever be a substitute for cholesterol-lowering, but it might very well be an add-on."

A Quick Review

Cholesterol is often the key culprit in evaluating the risk of heart disease. Additionally, some evidence suggests that inflammation markers can also evaluate heart health. 

If you have high cholesterol or inflammation, consult a healthcare provider about lifestyle changes you can make to reduce your risk of heart disease. Quitting smoking, regularly exercising, following a healthy Mediterranean-style diet, and managing a healthy weight may help.