Has your cholesterol skyrocketed on a low carb or ketogenic diet?
Or did it start out already high, and hasn’t come down like you thought it would after cutting carbs for a while?
Is your doctor on your case to “do something” about it? Are they pushing you to take cholesterol-lowering medication and stop that crazy high-fat diet you’ve been following?
Or maybe your doctor’s actually pretty easygoing about it, but you are alarmed by the big jump in your cholesterol since you started low carb. Maybe you’re wondering if all that butter, cheese, bacon, and red meat isn’t quite such a good idea after all...
People who adopt carbohydrate-restricted diets have widely varying effects on their lipid profile. Generally speaking, triglycerides go down and HDL goes up. This is practically a given. Happens like clockwork. Totally predictable. If you were the betting kind, you could put money on it and have a virtually guaranteed return. And this is a good thing. More and more evidence is emerging that regardless of your total cholesterol or LDL, the triglyceride-to-HDL ratio is a strong predictor of cardiovascular risk.
According to Drs. Phinney and Volek in their book, The Art and Science of Low Carbohydrate Living:
“The triglyceride/HDL ratio provides a broader assessment of risk, and its relationship with insulin resistance makes it far superior to LDL-C. And how best to improve your triglyceride/HDL ratio? The striking reductions in plasma triglycerides and consistent increases in HDL-C in response to low carbohydrate diets are unparalleled by any other lifestyle intervention, or even drug treatment, and therefore represents the most powerful method to improve this ratio.”
LDL is a different story. In some people, LDL goes down, but in others, it goes up. Something that happens on a low carb diet often, but not always, is a shift from LDL particles that are “small and dense” to LDL particles that are “large and fluffy.” Even when the total LDL goes up, the pattern of the particle makeup shifts. It’s believed—but has not been proven conclusively—that the latter pattern, called “pattern A,” is less atherogenic. That is, when your LDL particles are predominantly the large, fluffy type, they’re less likely to “clog your arteries” (*groan*) and cause a heart attack, stroke, or other cardio/cerebrovascular disease than when your particles are predominantly small & dense, called “pattern B.” So, on balance, even if LDL goes up on a low carb diet, it’s believed that the shift from pattern B to pattern A is a beneficial change and represents an improvement in your cardiovascular health.
But what if your total cholesterol or LDL absolutely skyrockets? Does your particle pattern even matter then? If your total cholesterol is 300, 400, 500, or higher, and your LDL is 200 or higher, surely—surely—all that cholesterol has to be clogging your arteries, right? Surely your very next slice of bacon could have you staring down the barrel of cardiac arrest, right? I mean, even if your triglycerides are low and your HDL is high, and your glucose and insulin are low, all your inflammatory markers are low, you’ve lost 60 pounds, your energy levels are through the roof, and your doctor has stopped your GERD medication, your beta-blocker, and your insulin injections, there’s no way your cholesterol could be that high and not cause trouble.
Not so fast.
Probably the single most important thing to know with regard to cholesterol is that neither the total amount of cholesterol nor the amount of LDL particles, nor even the size/pattern of your LDL particles tells you anything about the amount of calcification in your arteries—that is, how “clogged” your blood vessels are. And yet, many doctors who aren’t up on the latest research … or, truth be told, research from decades ago … will still want to give you a prescription for a statin based on nothing but your total cholesterol. In fact, they might even be accused of malpractice if they don’t send you away with a statin prescription for your “high” cholesterol. (Never mind that statins come with some very serious and dangerous side-effects, including increased risk for type 2 diabetes!)
My friend Dave Feldman over at cholesterolcode.com is doing some mind-blowing research that blows the lid off everything we thought we knew about cholesterol—even those of us in the low carb and keto community, who already knew there were massive problems with the cholesterol “story.”
He’s identified a subset of low carbers he calls “lean mass hyper-responders.” These folks are, by all accounts, in extremely good health. They’re lean, fit, highly active, have very low insulin and triglycerides, high HDL (over 100, in some cases!), and by just about all other parameters appear to be supreme specimens of human health and athletic performance. I say “just about” all other parameters, because these people have sky-high total cholesterol and LDL. Total cholesterol well above 300 in most cases, and LDL over 200. (Hence the name "hyper-responder" -- meaning, when these people adopt a low carb diet, their cholesterol goes through the roof.) Is this cause for concern? Should they quit the coconut oil and avocados and go back to fueling their running or biking with pasta and bagels?
Or, might there be some other way of assessing actual cardiovascular disease risk without using surrogate markers, like cholesterol? Because that’s the thing, dear readers: cholesterol is a measurement, not a disease. “High cholesterol” is not an illness. (Despite your doctor possibly being able to code for that and bill your insurance company.)
Once more, for emphasis: the amount of cholesterol and the number of LDL particles carrying it in your bloodstream tell you nothing about the presence or absence of damage or disease in your blood vessels or heart muscle.
This being the case, it would nice if there was some method of detecting actual cardiovascular disease. Actual buildup of plaque in the blood vessels, rather than a measurement of a substance contained in the blood traveling through those vessels. Ya’ll with me so far?
Okay. The good news is, THERE IS SUCH A METHOD! It’s called the coronary artery calcium scan, or CAC test for short. I wrote a detailed post about it for Heads Up Health. It is probably one of the most important things I’ve ever written—for just about everybody concerned with their health, but most especially for low carbers and keto folks whose total cholesterol and/or LDL are in the stratosphere and they’ve got some nagging doubts about what this might mean for them.
I didn’t want to rewrite it just to post it on my own blog, so here’s the link, and I give it to you along with my strongest encouragement to give it a read. It might be very educational for you, even if you already kinda-sorta “know” the whole cholesterol deal is bogus.
I could say more about the CAC test here, but honestly, it’s all in that post, so hop on over to Heads Up Health and check it out. The one thing I will say is that some of Dave's lean mass hyper-responders have done CAC tests, and most of these folks -- who have astronomically high LDL -- had zero -- zero arterial calcification. Zero evidence of cardiovascular disease. So much for cholesterol clogging the ol' arteries, eh?
If you’d like to learn more about just how far off the mark conventional thinking is on cholesterol, here are my top book recommendations, all of which are quick and easy reads, intended for a lay audience. There’s just enough science to get your learnin’ on, but not so much that your eyes will glaze over and you’ll feel overwhelmed:
- The Great Cholesterol Myth, by Jonny Bowden, PhD and Stephen Sinatra, MD
- Cholesterol Clarity, by Jimmy Moore and Eric Westman, MD
- The Cholesterol Myths, by Uffe Ravnskov, MD, PhD
I also recommend just about any video Dave Feldman has done on his cholesterol research, many of which can be found here.
Additionally, I did a podcast with Dave Korsunsky from Heads Up Health not long ago. We talked about interpreting labwork in the context of low carb/keto, and how some of the reference ranges aren’t what they’re cracked up to be. You can find that here.
P.S. I know I’ve been slacking on the blog lately. My apologies. I have a couple of very big, very important posts coming up on insulin, obesity, and type-2 diabetes. Lots of really fascinating stuff that I think will be new for many of you. (It was to me!) Unfortunately, because they’re big and important, they’re taking a long time to write. When I’m writing about things that really matter, I want to make sure I do the material justice, and that means the posts take extra long to write. (And my gold medal level of procrastination doesn’t help.) Anyway, I know you’re probably wishing I’d get back to writing “real” posts, and I will, soon. Thanks for your patience! In the meantime, the CAC post really is a doozy.
Disclaimer: Amy Berger, MS, CNS, NTP, is not a physician and Tuit Nutrition, LLC, is not a medical practice. The information contained on this site is not intended to diagnose, treat, cure, or prevent any medical condition and is not to be used as a substitute for the care and guidance of a physician. Links in this post and all others may direct you to amazon.com, where I will receive a small amount of the purchase price of any items you buy through my affiliate links.