Understanding Your Cholesterol, part 1

What is cholesterol and what does it do? Does the cholesterol you eat impact cholesterol levels in your blood? Is it possible to have too low levels of cholesterol? What do all those numbers mean on your bloodwork?  Is high cholesterol really a good indicator for heart disease?  In this two part article, we’ll clarify the mystery surrounding all matters cholesterol.  

What is cholesterol and what does it do? Contrary to popular opinion, cholesterol doesn’t exist to shorten your lifespan, but actually helps your body thrive. It is a waxy-like substance that serves a number of functions in the body, including but not limited to:

  • synthesis of sex hormones including cortisol, testosterone, estrogen
  • production of bile acids for digestion of fats
  • synthesis of vitamin D
  • insulation and connection of nerve cells
  • fluidity and integrity of all cell membranes

The majority of the cholesterol in the body is actually made by the liver.

Does the cholesterol you eat impact cholesterol levels in your blood? Blood cholesterol is not determined by dietary intake of cholesterol.1, 2 The science reflects that it is not dietary cholesterol that causes high blood cholesterol. For example, eggs are one of the foods highest in cholesterol. Historically, eggs have been villainized as a major culprit, when in fact, there are many studies that indicated that dietary intake of egg has a beneficial effect on cholesterol levels.

Is it possible to have too low levels of cholesterol? People with both decreasing cholesterol levels and persistently low cholesterol levels were significantly associated with an increased risk of all-cause mortality compared to those remaining at a stable middle cholesterol levels3. Low levels of cholesterol are associated with, but not limited to, the following:

  • cancer mortality in subjects with age ≥ 65 years
  • increased levels of cardiovascular disease
  • difficulty digesting fats, including fat soluble vitamin E
  • failure to thrive in infants
  • intellectual disability
  • retinal degeneration
  • damage to sensory nerves
  • difficulty with balance and speech
  • death!

As you can see, the subject of cholesterol and its impact on overall health is not as simple as high cholesterol is bad and low cholesterol is good. Moderation of this important substance is vital. In my next newsletter article, we’ll review what the numbers on cholesterol bloodwork actually mean so you will better understand your lab results and strategies you can implement to improve your overall health.

References:

  1. Fernandez ML, Murillo AG. Is There a Correlation between Dietary and Blood Cholesterol? Evidence from Epidemiological Data and Clinical Interventions. Nutrients. 2022 May 23;14(10):2168. doi: 10.3390/nu14102168. PMID: 35631308; PMCID: PMC9143438.
  2. Soliman GA. Dietary Cholesterol and the Lack of Evidence in Cardiovascular Disease. Nutrients. 2018 Jun 16;10(6):780. doi: 10.3390/nu10060780. PMID: 29914176; PMCID: PMC6024687.
  3. Jeong S-M, Choi S, Kim K, Kim S-M, Lee G, Son JS, et al. (2018) Association of change in total cholesterol level with mortality: A population-based study. PLoS ONE 13(4): e0196030. https://doi.org/10.1371/journal.pone.0196030
Tasleem Kassam