Written by Kayla McDonell, RD — Medically reviewed by Atli Arnarson BSc, PhD
September 26, 2019
Overview
High blood cholesterol levels are a known risk factor for heart disease.
For decades, people have been told that the dietary cholesterol in foods raises blood cholesterol levels and causes heart disease.
This idea may have been a rational conclusion based on the available science 50 years ago, but better, more recent evidence doesn’t support it.
This article takes a close look at the current research on dietary cholesterol and the role it plays in blood cholesterol levels and heart disease.
What is cholesterol?
Cholesterol is a waxy, fat-like substance that occurs naturally in your body.
Many people think that cholesterol is harmful, but the truth is that it’s essential for your body to function.
Cholesterol contributes to the membrane structure of every cell in your body.
Your body also needs it to make hormones and vitamin D, as well as perform various other important functions. Simply put, you could not survive without it.
Your body makes all the cholesterol it needs, but it also absorbs a relatively small amount of cholesterol from certain foods, such as eggs, meat, and full-fat dairy products.
SUMMARY
Cholesterol is a waxy, fat-like substance that humans need to survive. Your body makes cholesterol and absorbs it from the foods you eat.
Cholesterol and lipoproteins
When people talk about cholesterol in relation to heart health, they usually aren’t talking about cholesterol itself.
They are referring to lipoproteins — the structures that carry cholesterol in the bloodstream.
Lipoproteins are made of fat (lipid) on the inside and protein on the outside.
There are several kinds of lipoproteins, but the two most relevant to heart health are low-density lipoprotein (LDL) and high-density lipoprotein (HDL).
