Cholesterol is like a punching bag in the nutrition world. It gets hit by so many people, from vegans to vegetarians to low-fat dieters. And for society, it’s been made out to be public enemy #1. But do you even know what it is or even its purpose? Are all the accusations true? Let’s explore both the good and the bad sides of cholesterol and find out if it’s friend or foe!

The 411 on Cholesterol

“Don’t eat cholesterol!” “Cholesterol will give you a heart attack!” “If you eat cholesterol, you’ll die!” That’s all fine and good, but do you know what cholesterol even is? Here’s the scoop.

You can’t avoid cholesterol. It’s a waxy substance that’s produced mainly by the liver along with every cell in the body. Without it, we cannot survive, as it plays a critical role in many bodily processes. You can run, you can hide, but you cannot completely avoid cholesterol- your body will continue making it for you. [1]

Functions

“Cholesterol is essential to life.”

Henry J. Pownall, Ph.D., medical biochemist, Houston Methodist Research, Texas

Cholesterol is involved in several important processes, including:

• Hormone Production (an essential precursor or “ingredient” for making estrogen, cortisol, testosterone, adrenal hormones, as well as Vitamin D- cholecalciferol)
• Cellular Health (maintains both the structure and fluidity of cells)
• Nerves (is part of the protective myelin sheath that surrounds nerves)
• Nutrient Absorption (releases bile salts that help to digest fat and fat-soluble vitamins such as A, D, E, and K)

[1] [2] [3]

Types

There are different types, or forms, of cholesterol that you need to remember.

LDL (low-density lipoproteins), which is a combination of different fats and protein. It carries most of the cholesterol that’s delivered to cells. However, it is often called the “bad guy” due to its ability to clog arteries in high amounts.

VLDL (very low-density lipoproteins), which is similar in makeup to LDL with a few differences. The liver creates VLDL to help carry triglycerides, a fatty byproduct of digestion. Triglycerides are either used as energy by our cells or stored in the body for later use. They’re also dangerous because a buildup of them leads creates plaque in the arteries.

HDL (high-density lipoproteins), a “good” kind of cholesterol that helps to transfer excess cholesterol out of the body (preventing buildup and plaque in the arteries).

[2] [3] [4] [5]

The Dangers of Cholesterol

Cholesterol isn’t just bad. It’s dangerous. But only in the right context. As you’ve seen, cholesterol is necessary for bodily function. Without it, we couldn’t live. However, too much of it can lead to disease- specifically, heart disease.

High amounts of LDL (both VLDL and LDL) in the bloodstream start to deposit in the arteries. They’ll eventually start to harden, which is a condition known as atherosclerosis. Blood flow soon gets restricted, which means the heart has to work overtime to push enough blood through them. If things don’t improve, cholesterol will keep building up to the point they create plaque within the (already narrow) arteries. And it doesn’t stop there! Soon there will be a disruption in blood flow to the heart.

A few things can happen here. First is angina, or chest pain. It’s not a heart attack but rather a sign that the heart is struggling to receive enough blood. Second is the development of blood clots made from fallen pieces of plaque. The third is that the arteries will become completely blocked, resulting in either a heart attack or stroke (depending on where the blockages are). By the way, these blockages also interferes with blood flow to the rest of the body, like the legs, feet, and intestines (a condition called peripheral arterial disease or PAD).

Other consequences of high cholesterol include gallstones, plaque in the brain (which causes damage and leads to Alzheimer’s), and imbalances in the nervous system.

[2] [3] [6]

Dietary Cholesterol

Your first reaction might be to cut off all cholesterol-containing foods from your diet. But hold on for a moment, because the story here isn’t so black and white. For most people, dietary sources of cholesterol from foods like eggs do not affect blood cholesterol. The body regulates the amount of cholesterol that goes into the blood. If it sees that there’s going to be too much, then it slows down cholesterol production (and vice versa). With high-cholesterol foods, the body produces less. The only time when this doesn’t happen is in people that are known as hyper responders; they make about 25% of the population. Curiously, hyper responders aren’t necessarily at risk for heart disease. Even though dietary cholesterol raises their blood cholesterol, their ratio of bad LDL to good HDL mostly stays the same, with there being more good than bad.

[2] [7] [8]

The Big Picture

Heart disease isn’t plain and simple; it’s very complex. High cholesterol isn’t the only thing we should be blaming. Other causes of heart disease include high blood pressure, smoking, drinking, inflammation, oxidative stress, and being overweight or obese.

When it comes to maintaining healthy cholesterol, you need to look at your overall diet. Sure, you might be eating eggs, but you’re also eating other foods like vegetables, proteins, fruits, etc. (Plus,antioxidant-rich foods like pomegranates and blueberries also help to maintain healthy cholesterol levels.) You also need to consider the amount and types of fat you’re consuming, such as monounsaturated fats from olive oil and omega-3 fats from salmon. If all you’re eating is cholesterol, then there’s a problem. Finally, be mindful of your blood sugar. Believe it or not, there’s an association between high blood sugar and increased risk of atherosclerosis, so don’t assume that avoiding cholesterol completely protects you!

Outside of your diet, there are other things that you can do to balance cholesterol. Regular exercise, maintaining a healthy weight, and lowering inflammation all have been shown to prevent heart disease and high cholesterol.

[2] [7] [8]

Bottom Line

Cholesterol is not the enemy. It’s incredibly important for our health. In the rare case that someone is a hyper responder or is genetically predisposed to high amounts is when you should be mindful of your intake. And even then, you shouldn’t ignore other healthy foods like antioxidant-rich plant-based foods that help to balance it. Even low carb and keto folks can be OK so long as they remember to get their fats from other sources like avocados, nuts, seeds, olives, and fish. With cholesterol and heart disease, it’s all about context. You can’t only blame cholesterol. Inflammation, poor habits like drinking and smoking, and inflammation are just some of the other triggers behind heart disease.

Sources:

[1] https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/cholesterol
[2] https://www.dietdoctor.com/low-carb/cholesterol-basics
[3] https://www.healthline.com/health/high-cholesterol/why-is-cholesterol-needed
[4] https://www.healthline.com/health/vldl-vs-ldl#testing
[5] https://www.webmd.com/cholesterol-management/qa/what-are-triglycerides
[6] https://www.healthline.com/health/cholesterol/effects-on-body#1
[7] https://www.healthline.com/nutrition/dietary-cholesterol-does-not-matter#section5
[8] https://www.healthline.com/health-news/isnt-really-unhealthy-to-eat-eggs#Getting-to-the-yolk-of-it