Today's Claim in Focus: Is low LDL-C harmful to health? Does high cholesterol benefit health?
In this episode Alan and Danny discuss the role of cholesterol in the body and claims that are made suggesting low levels of blood cholesterol are harmful to health.
Starting with the premise that cholesterol is an important molecule in the body and plays a role in many processes, discussed are two related claims:
- we should avoid low cholesterol levels as it can harm our health
- elevated levels of cholesterol may actually be protective against disease or mortality.
The episode also critiques claims about cholesterol being “conditionally essential” and that low LDL-C/ApoB increases risk of mortality, cancer and infection.
Example claims discussed:
- Low Carb Conference – Dr. Nadir Ali
- Mark Sisson – on JRE #1624
- Paul Saladino podcast - “How High Cholesterol Can Be Healthy, and Low Cholesterol Could be Harmful”
- 2016 systematic review by Ravnskov et al.
Thank you for this podcast. Three questions/comments. 1) You repeatedly discussed a threshold for LDL over which cardiovascular disease occurs. Was there mention of what the threshold is in terms of mg/dL? 2) One of the ongoing problems is that no study to date has controlled for carb intake below a certain amount. Sugar seems to change the size of LDL particles, as do stress, smoking, etc, so how can we draw any truly applicable conclusions from any studies? 3) Cardiac testing will tell us way more than a cholesterol test will. Treadmill stress test, echocardiogram, vascular scan, or even a CT angiogram or CT coronary artery calcium score in terms of plaque buildup and CV risk. Thoughts? Thank you for your time!
In short, there is no “floor” to the benefit (in terms of CVD risk reduction) for LDL-lowering: https://pubmed.ncbi.nlm.nih.gov/29336946/ This is discussed more with the author of that paper, in episode 381: https://sigmanutrition.com/episode381/
I don’t think there’s any substance to claiming we can’t draw conclusions on this issue due to the impact of sugar on LDL particles. We can look across a number of lines of evidence, all showing elevated number of LDL particles increases risk. Whether some particles are slightly bigger/smaller, doesn’t really change the atherogenic potential of an elevated number of LDL (or non-HDL) particles.
The statement that “cardiac testing will tell us way more than a cholesterol test will” is unfortunately just not correct. As discussed in this episode (and other places I’ll list below), ASCVD is a disease process that develops over a long time-course (decades) and the risk of elevated lipoproteins is a cumulative, integrated exposure over the course of the lifespan. So just looking at a currently low CAC score for example, really doesn’t allow you to say that elevated LDL is posing no risk.
For more context an explanation, I’d point you towards some of our written materials on this.
First, we have a three part series, with part one perhpahs being the most relevant to your concerns: https://sigmanutrition.com/lipids/
Second, on the topic of this episode, we have a written piece that clarifies some aspects more: https://sigmanutrition.com/cholesterol-mortality/
Hopefully, those will provide the appropriate support for my comment.
Thanks so much for listening to the podcast and for the comment!