Low-carb and ketogenic diets are incredibly healthy.
They have clear, potentially life-saving benefits for some of the world's most serious diseases.
This includes obesity, type 2 diabetes, metabolic syndrome, epilepsy and numerous others.
According to these improvements, low-carb diets should reduce the risk of heart disease.
But even if these risk factors improve on average, there can be individuals within those averages that experience improvements, and others who see negative effects.
There appears to be a small subset of people who experience increased cholesterol levels on a low-carb diet, especially a ketogenic diet or a very high fat version of paleo.
This includes increases in Total and LDL cholesterol... as well as increases in advanced (and much more important) markers like LDL particle number.
Of course, most of these "risk factors" were established in the context of a high-carb, high-calorie Western diet and we don't know if they have the same effects on a healthy low-carb diet that reduces inflammation and oxidative stress.
However... it is better to be safe than sorry and I think that these individuals should take some measures to get their levels down, especially those who have a family history of heart disease.
Some simple adjustments will do just fine and you will still be able to reap all the metabolic benefits of eating low-carb.
Interpreting cholesterol numbers can be fairly complicated.
Most people are familiar with Total, HDL and LDL cholesterol.
People with high HDL (the "good") have a low risk of heart disease, while people with high LDL (the "bad") have an increased risk.
But the true picture is much more complicated than "good" or "bad" ... the "bad" LDL actually has subtypes, primarily based on the size of the particles.
However, science is now showing that the most important marker of all is the LDL particle number (LDL-p), which measures how many LDL particles are floating around in your bloodstream (6).
This number is different from LDL concentration (LDL-c), which measures how much cholesterol your LDL particles are carrying around. This is what is most commonly measured on standard blood tests.
It is important to get these things tested properly in order to know if you truly have anything to be concerned about.
If you can, have your doctor measure your LDL-p (LDL particle number)... or ApoB, which is another way of measuring LDL particle number.
If your LDL cholesterol is high, but your LDL particle number is normal (called discordance), then you probably have nothing to worry about (7).
On a low-carb diet, HDL tends to go up and triglycerides down, while Total and LDL cholesterol tend to stay the same. LDL particle size tends to increase and LDL particle number tends to go down. All good things (8, 9).
But again... this is what happens on average. Within those averages, it appears that a subset of people on a low-carb ketogenic diet DO get a rise in Total cholesterol, LDL cholesterol and LDL particle number.
This phenomenon is described in detail here by Dr. Thomas Dayspring, one of the world's most respected lipidologists (hat tip to Dr. Axel Sigurdsson): Lipidaholics Anonymous Case 291: Can losing weight worsen lipids? If you want to dig into the science behind this paradoxical rise in cholesterol on a ketogenic diet, then read that article (you need to sign up with a free account).
Unfortunately, not everyone can have advanced markers like LDL-p or ApoB measured, because these tests are expensive and not available in all countries.
If your Non-HDL is elevated, then that is reason enough to take measures to try to get it down.
Bottom Line: A subset of individuals do experience increased cholesterol on a low-carb diet, especially if it is ketogenic and ultra high fat. This includes elevated LDL, Non-HDL and important markers like LDL particle number.
It's also important to rule out medical conditions that can cause elevated cholesterol. These really don't have anything to do with the diet itself.One example of that is reduced thyroid function. When thyroid function is lower than optimal, Total and LDL cholesterol can go up ( 12, 13).
Another thing to consider is weight loss... in some individuals, losing weight can temporarily increase LDL cholesterol.
If your levels go up at a time when you are losing weight rapidly, you may want to wait for a few months and then measure them again when your weight stabilizes.
It's also important to rule out a genetic condition like Familial Hypercholesterolemia, which afflicts about 1 in 500 people and is characterized by very high cholesterol levels and a high risk of heart disease.
Of course, there are many subtle genetic differences between us that can determine our responses to different diets, such as different versions of a gene called ApoE (14).
Now that all of that is out of the way, let's take a look at some actionable steps that you can take to bring those cholesterol levels down.
Bottom Line: Make sure to rule out any medical or genetic condition that may be causing you to have high cholesterol.
"Bulletproof" coffee is very trendy in the low-carb and paleo communities.
It involves adding 1-2 tablespoons of MCT oil (or coconut oil) and 2 tablespoons of butter into your morning cup of coffee.
I haven't tried it myself, but many people claim that it tastes delicious, gives them energy and kills their appetite.
However, even though "normal" amounts of something are good for you, it doesn't mean that massive amounts are better.
All the studies showing that saturated fat is harmless used normal amounts... that is, amounts that the average person consumes.
There is no way to know what happens if you start adding massive amounts of saturated fat to your diet, especially if you're eating it instead of other more nutritious foods. This certainly isn't something that humans evolved doing.
I've also heard reports from low-carb friendly docs (Drs Spencer Nadolsky and Karl Nadolsky. They had low-carb patients with massively increased cholesterol whose levels normalized when they stopped drinking bulletproof coffee.
If you drink bulletproof coffee and have cholesterol problems, then the first thing you should do is try removing this from your diet.
Bottom Line: Try removing bulletproof coffee from your diet. This alone may be sufficient to solve your problem.
However... if you have problems with cholesterol, then it is a good idea to try to replace some of the saturated fats you are eating with monounsaturated fats.
This simple modification may help to bring your levels down.Cook with olive oil instead of butter and coconut oil. Eat more nuts and avocados. These foods are all loaded with monounsaturated fats.
If this alone doesn't work, then you may even want to start replacing some of the fatty meat you are eating with leaner meat.
I can't emphasize olive oil enough... quality extra virgin olive oil has many other benefits for heart health that go way beyond cholesterol levels.
It is definitely a superfood for the heart and I think anyone at risk of heart disease should be using olive oil, no matter whether their cholesterol is high or not.
It is also important to eat fatty fish that is high in Omega-3 fatty acids, at least once per week. If you can't or won't eat fish, supplement with fish oil instead.
Bottom Line: Monounsaturated fats, like those found in olive oil, avocados and nuts, may have cholesterol lowering effects compared to saturated fats.
There is a common misunderstanding that a low-carb diet has to be ketogenic.
That is, that carbs should be low enough for the body to start producing ketones out of fatty acids.
This type of diet appears to be the most effective for people with epilepsy. Many people also claim to get the best results, mental and physical, when they're in ketosis.
However... more modest carb restriction can still be considered low-carb.
Although there is no clear definition, anything up to 100-150 grams per day (sometimes higher) can be classified as a low-carb diet.
It is possible that some individuals see cholesterol increases when they're in ketosis, but improve when they eat just enough carbs to avoid going into ketosis.
You can try eating 1-2 pieces of fruit per day... maybe a potato or sweet potato with dinner, or small servings of healthier starches like rice and oats.
Depending on your metabolic health and personal preferences, you could also just adopt a higher-carb version of paleo instead.
This can also be a very healthy diet, as demonstrated by long-living populations like the Kitavans and Okinawans, who ate a lot of carbs.
Although ketosis can have many incredible benefits, it is definitely not for everyone.
Exercising, getting better sleep and minimizing stress levels can also help.
None of the advice in this article should be considered as medical advice. You should discuss this with your doctor before making any changes. Keep in mind that I am NOT suggesting that saturated fat or low-carb diets are "bad." This is only meant as a troubleshooting guide for the small subset of people who have cholesterol problems on a low-carb and/or paleo diet.
I have not changed my mind about low-carb diets. I still eat a low-carb diet myself... a non-ketogenic, real food based low-carb diet with about a 100 grams of carbs per day.
At the end of the day, low-carb diets are still incredibly healthy and the benefits FAR outweigh the negatives for most people, but a subset of individuals may need to make some adjustments in order to make the diet work for them.