Understanding Cholesterol and Low Carb Diet
Medically reviewed by Dr. George Kosco, DO on March 14, 2020
You’ve been told that improving your diet will improve your cholesterol profile, but what do you do if your cholesterol profile doesn’t improve or gets worse after changing your diet?
This is the experience that some people have when they follow a low-carb diet.
In this article and video, I explain what is going on and how you can tell if you are doing your body more harm or good by cutting carbs.
[Video] Understanding Cholesterol and Low Carb Diet
In this video, I simplify the incredibly complex topic of cholesterol to help you understand how your diet affects your total cholesterol and LDL-cholesterol levels.
To start with, you need to know that your body needs cholesterol.
It is a part of every cell membrane, and it’s an essential part of your hormones like estrogen and testosterone.
So, the goal is never to get your total cholesterol to zero.
When you get your blood tested, you usually see your total cholesterol level.
Total Cholesterol is a calculation that the lab gets by adding your HDL and LDL cholesterol levels together with 20 percent of your triglyceride level.
Triglyceride is the fancy name for fat. And, you might know HDL as the “good” cholesterol and LDL as the “bad” cholesterol.
HDL and LDL are abbreviations; their real names are High-Density Lipoprotein and Low-Density Lipoprotein.
So, they are both lipoproteins.
And, if you look closely at that word, you see it’s actually two words squished together lipid + protein.
Lipoprotein is a nice name because a lipoprotein is, for the most part, a mixed molecule that contains both fats and protein.
This unique structure allows fat to move around that watery transport system that you call your blood.
If you think back to your childhood science class, you remember that oil and water don’t mix. Well, fat and blood don’t mix.
So, fats, by themselves, can’t move through your blood unless they have something to carry them and that something is this nice neat lipoprotein package.
The Takeaway for Understanding Cholesterol:
The primary job of BOTH “good” HDL and “bad” LDL is to carry cholesterol (a fatty substance) and triglycerides (i.e. fats) through your blood.
It is the direction in which these lipoproteins carry cholesterol that gives them that reputation of being good or bad.
HDL is the housekeeper of the body, it goes out and gathers up cholesterol in your body and then heads for your liver where it drops off its cargo.
That dumped cholesterol is either recycled as one of those good things, like making hormones or cell membranes or it’s turned into bile. Bile helps with digestion and then gets eliminated from your body.
So just remember HDL as Healthy and that you always want more of them.
LDL is the one that deserves a closer look when examining your health.
LDL works in the opposite way of HDL. These molecules carry cholesterol out into your body (that’s not necessarily a bad thing).
LDL is made inside your liver. These molecules are made up of protein, cholesterol, and triglycerides.
When LDL starts its life, it’s called Very Low-Density Lipoprotein or VLDL.
VLDL contains some cholesterol but is mostly filled with triglycerides.
Those triglycerides are needed for energy, so when they leave the liver, their cargo quickly gets dropped off at cells that need energy, and the VLDL turns into LDL that contains fewer triglycerides but still has its cholesterol.
I like Dave Feldman’s analogy of LDL particles as cruise ships.
In his video, he asks you to imagine an LDL particle as a cruise ship where the passengers are triglycerides and the lifeboats are cholesterol.
As the LDL ship is cruising through your blood, it’s dropping off its passengers at different ports. In other words, it’s dropping off its triglycerides at your cells.
This analogy explains how low-carb diets help you lose weight.
Low Carb Diet, Cholesterol, & Weight Loss
A low-carb diet turns you into a fat (triglyceride) burner instead of a sugar (carbohydrate) burners.
Carbohydrates are the easiest fuel for your body to convert to energy.
But, if you are not eating many carbs, then your body needs to run on the alternative fuel which is triglycerides.
So, a person on a low carb diet is burning their “passenger” triglycerides for energy.
What’s happening in the person who’s eating a lot of sugar and carbs throughout the day?
They still have triglycerides onboard their LDL cruise ships, but those fats are not needed for energy.
The fats have to go somewhere, so they get dropped off at the fat cells and stored as future energy.
When you eat sugar, white bread, and frappe’ drinks from fast food restaurants or cafés you are constantly feeding your fat cells.
Understanding Cholesterol’s Usefulness
Let’s get back to our cruise ship analogy from Dave Feldman that I mentioned earlier.
Cruise ships have lifeboats, and in the analogy, we see that the lifeboats represent cholesterol molecules.
Lifeboats go along for the ride.
The captain of the ship could drop them off if they are needed somewhere in your body, but if they aren’t needed, then they return to port, which is your liver.
In your liver, the entire cruise ship along with its cholesterol is taken out of service, and the cholesterol is recycled or prepared for excretion.
So, what might cause these lifeboats to be needed by your body?
In other words, what might your body need cholesterol for other than the good things that I already mentioned, like making hormone and cell membranes?
Cholesterol is a Band-Aid
Cholesterol is an important component of wound healing within your blood vessels. It acts much like a Band-Aid.
So what happens to blood vessels?
How do you hurt a blood vessel to the point where it needs a Band-Aid?
Well, this damage typically comes from inflammation and inflammation is largely caused by a poor diet that contains inflammatory foods, such as sugar, refined carbs, high fructose corn syrup like you get in soda and processed foods
Besides, inflammatory foods, we also know that chronically increased insulin levels and high blood pressure leads to blood vessel damage, but those two conditions are closely associated with a poor diet.
Don’t think that because you feel okay when you eat junk food that you are getting away with anything.
You can’t outrun the biological impact of a poor diet. You don’t feel inflammation in your vessels, but it’s happening.
Understanding Inflammation and Cholesterol
When inflammation causes rough patches in the lining of your blood vessel, cholesterol rushes over to help patch it up.
This rush to help is where cholesterol gets its bad reputation because as that cholesterol fills in that gap in the vessel lining, the lumen or hole in which the blood passes through gets narrower, increasing your risk of cardiovascular disease.
Cholesterol – The Innocent Good Samaritan?
Plaque in the arteries is bad, but we are blaming the wrong culprit.
We are blaming the Band-Aid when, in reality, what caused the problem was inflammation caused by a poor diet.
Yes, LDL is carrying cholesterol out into your body, but if there is no need for it, it stays on the “cruise ship” and returns to “port” (a.k.a. your liver) where it gets broken down, reused or excreted as bile.
So the question becomes, is cholesterol innocent? In other words, “is it okay to have a super high total cholesterol level or LDL cholesterol level in your blood.”
Probably not, but…
The scientific community differs a lot from the medical community on how much cholesterol is too much.
For instance, if your doctor sees a total cholesterol level of 240 or higher or an LDL cholesterol level above 160, then he or she is likely to prescribe a statin to lower it.
So, we need to dig deeper here to understand what’s really going on if your LDL cholesterol level is not coming down or is going up despite the fact that you are on a healthy low-carb, low-sugar diet.
And, we also want to take a look at how to tell if that elevated LDL level is dangerous or harmless.
Digging Deeper to Understand Cholesterol and Low Carb Diet
I already mentioned that low-carb diets are very good at shrinking your fat cells by encouraging them to release fat.
But what exactly is coming out of our shrinking fat cells?
We know that triglycerides (the fats themselves) come out of fat cells as they shrink, but what we don’t think about is that they also release cholesterol as they shrink.
So when you are losing fat, you are releasing low-density lipoprotein cholesterol into your bloodstream.
And, remember that the triglyceride can be burned as energy, but cholesterol cannot be burned, so it has to make its way through the blood and get to the liver where it can be dealt with.
So, while it doesn’t happen to everyone, it is not unusual to see elevated total cholesterol and LDL cholesterol when you are on a rapid fat loss diet like a low carb diet.
These elevated levels may be more prevalent in someone who has an underlying issue like insulin resistance or diabetes.
Elevated Cholesterol – Is It Harmful to Your Health?
An elevated cholesterol finding, by itself, is not a reason to panic.
First of all, your level could naturally come down once you reach your goal weight, because your fat cells stop shrinking, and therefore stop releasing cholesterol.
Secondly, it is important to know that not all LDL particles are the artery-clogging kind.
So, to really tell if your elevated LDL finding is dangerous, you need a different blood test that goes beyond the Standard Lipid Panel to look at the size of your LDL particles.
That blood test is called an NMR Lipoprofile or Nuclear Magnetic Resonance Lipoprofile.
It is a blood test that reveals if your LDL particles are big and fluffy or small and dense.
Size Matters for LDL Particles
Years ago, science didn’t know that there were different sizes of LDL particles. Some particles are big, light, and fluffy and others are small and dense.
The big fluffy ones are the safe ones, while the small, dense ones are the artery-damaging particles.
What Determines the Size of LDL Particles?
Genetics might play a part in determining the size of your LDL particles, but your diet plays an important role.
Diet and LDL Particle Size:
- A diet low in carbs seems to increase particle size, which is what you want (1).
- A diet high in sugar, refined carbs, and high-fructose corn syrup decrease LDL particle size (2).
There also seems to be some evidence that the type of fat you include in your diet affects the size of the LDL particles.
- Unhealthy fats like trans fats, hydrogenated oils, and vegetable oils create small, bad LDLs (3).
- Healthy fats like avocados, nuts, seeds, coconut oil, and fatty wild-caught fish make good ones.
Conclusion: Cholesterol and Low Carb Diet
When it comes to cholesterol, all roads circle back to the foods you’re putting in your body. There is truly nothing better you can do for your health than change your diet.
What to Do If Your Cholesterol Level Remains High on a Low Carb Diet
1. Don’t panic.
As you move closer to your goal weight, your fat cells will stop shrinking, which means they will release less cholesterol into your bloodstream.
This may allow your cholesterol levels to normalize naturally.
2. Have an NMR Lipoprofile test.
This is a more precise look at your cholesterol profile. You want the number of small, artery-clogging LDL particles to be low, and the number of big, fluffy LDL particles to be high.
3. Look at your C-Reactive Protein levels.
This is apart of most blood cholesterol tests. It’s a marker that shows the level of inflammation in your body.
Low inflammation means less damage to your blood vessels, and less of a need for cholesterol to act as a Band-Aid (4).
4. Eat Plenty of Healthy Fats.
Make sure your diet contains plenty of healthy fats such as avocados, nuts, seeds, coconut oil, fatty fish, and other omega-3 fatty acids, and avoid unhealthy fats such as trans fats, hydrogenated oils, and vegetable oils.
5. Eat High-Fiber Carbs.
When you do eat carbs, make sure they have a high fiber-to-carb ratio.
Low-glycemic vegetables such as broccoli and cauliflower, celery, cucumbers, leafy greens, mushrooms, onions, peppers, and tomatoes are among your best choices.
6. Avoid sugar, refined carbs, and high fructose corn syrup.
These foods turn on the cholesterol making factory in your liver and pump out the small dangerous LDL particles.
(1)Evidence that supports the prescription of low-carbohydrate high-fat diets: a narrative review.
(2) Aeberli, I., Zimmermann, M. B., Molinari, L., Lehmann, R., L’Allemand, D., & Spinas, A. G. (2007, October 01). Fructose intake is a predictor of LDL particle size in overweight schoolchildren1,2,3. Am J Clin Nutr, 86 (4): 1174-1178
(3) Mauger, J., Lichtenstein, A. H., Ausman, L. M., Jalbert, S. M., Jauhiainen, M., & Ehnholm, A. C. (2003, September 01). Effect of different forms of dietary hydrogenated fats on LDL particle size1,2,3. Am J Clin Nutr, 78 (3): 370-375
(4) Seshadri, P., Iqbal, N., Stern, L., Williams, M., Chicano, K. L., Daily, D. A., . . . Rader, D. J. (2004, September 15). A randomized study comparing the effects of a low-carbohydrate diet and a conventional diet on lipoprotein subfractions and C-reactive protein levels in patients with severe obesity. The American Journal of Medicine, 117(6): 398-405
About the Author
Dr. Becky Gillaspy, DC graduated Summa Cum Laude with research honors from Palmer College of Chiropractic in 1991.