The keto diet is incredibly healthy with many benefits from losing weight to helping with chronic inflammation. The Body Reboot book says this low carb diet may also help treat diseases such as type 2 diabetes, epilepsy, metabolic syndrome, and more. For the most part, heart disease risk factors also tend to improve for most people. Some people may believe that the keto diet can cause heart disease, but that’s not always the case. Some people may experience heart disease, but overall the keto diet has positive effects. This article will outline various opinions on whether the keto diet’s impact may be on cholesterol levels.
Healthline mentions that for the most part people who go on the keto diet experience an improvement in their cholesterol levels, especially if they are overweight. However, there is a small group of people who may have increased cholesterol levels. See why:
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.
Fortunately, you don't need to go on a low-fat diet, eat veggie oils or take statins to get your levels down.
Some simple adjustments will do just fine and you will still be able to reap all the metabolic benefits of eating low-carb.
Diet Doctor also says that the amount of people who may experience higher cholesterol on a low carb diet is minimal, around 1-2%.
You may be wondering what the relationship is between Low-Density Lipoprotein Cholesterol (LDL) and the keto diet. Well, it turns out that it’s a lot more complicated than it seems. Very Well Fit explains the correlation in more detail below.
Although there is some controversy on this point, LDL cholesterol is considered “bad” in terms of heart disease risk. The relationship between low-carb diets and LDL cholesterol is more complex than with triglycerides and HDL cholesterol. There are some studies in which LDL is reduced on a low-carb diet, some in which it doesn't change, and some in which it goes up. But there is one thing about LDL changes which is consistent with low-carb diets, and that is that it causes a change in cholesterol particle size.
What Has Particle Size Got to Do With It?
The evidence is accumulating that the size of cholesterol particles has a lot to do with risk for heart disease. Basically, the smaller the particles are, the greater the risk — it is thought that perhaps the small particles lodge in the walls of blood vessels more easily.
The good news for those of us following a low-carb way of eating is that studies of diet and cholesterol particle size have consistently shown that low-carb diets produce larger-sized cholesterol particles.
Ruled.me further explains how a low-carb, high-fat diet may affect LDL levels.
Let’s go back to the research assessing how the low-carb, high-fat diets such as the ketogenic diet affect your LDL levels. In the meta-analysis by Bueno et al., low-carb diets were shown to increase HDL twice as much as low-fat diets after randomized controlled interventions. It also showed that there was a small increase in LDL-C in low-carb subjects compared to low-fat diet subjects who experienced no increase.
The research study by Brinksworth et. al also showed that low-carb diets yielded greater increases in HDL cholesterol when compared to a low-fat diet.
Key Takeaways: Some research suggests that high-fat, ketogenic diets can increase LDL-C by a small amount.
Even though there may be some cause for concern that bad cholesterol levels can increase, there are some studies, such as the 2006 International Journal of Cardiology study, which states otherwise. Ruled.me discusses this study below.
Another study in primarily adult, female subjects showed similarly promising results. In a randomized, parallel clinical trial, researchers recruited 119 subjects for a 6 month long intervention. The mean age of the subjects was 44.9 years, their mean BMI was 34.4 kg/m2, and 76% were women.
59 of the subjects were randomized to a low-calorie ketogenic diet which included a nutritional supplementation of borage, fish and flaxseed oil. The second group of 60 consumed a reduced-calorie diet.
After the intervention, researchers noted that the ketogenic diet group had decreased their VLDL by 78%, their medium VLDL by 60%, and their small VLDL by 57%.  Additionally, their large LDL had increased by 54%, medium LDL decreased by 42%, and small LDL decreased by 78%.  Overall, the average particle size increased by 2% and the LDL particle concentration decreased by 11%.
This optimization in LDL cholesterol was less pronounced in the low fat group compared to the low-carb ketogenic diet group. It is important to mention that LCKD did not lower total LDL cholesterol. However, as mentioned previously, two studies by the Framingham Heart Study indicate that LDL-P is a stronger indicator than LDL-C.
In fact, one study stated that “…the group with the highest risk for cardiovascular events had high LDL-P and LDL-C, while the group with the lowest risk had low LDL-P but higher LDL-C.”  As a result of prior clinical research and their findings, the researchers stated that: “While the low carb, ketogenic diet did not lower total LDL cholesterol, it did result in a shift from small, dense LDL to large, buoyant LDL, which could lower cardiovascular disease risk.”
From this, we can conclude that a low-carb, ketogenic diet helps you optimize your LDL cholesterol.
The question remains for some people whether a low-carb diet can increase LDL and whether they should be worried. Keto Diet discusses what The American Journal of Clinical Nutrition study from 2010 revealed about the subject.
The President of the American Heart Association (AHA) recently issued a statement that lowering saturated fat intake by replacing it with unsaturated fats will lower total and LDL cholesterol and decrease risk of CVD.
However, several large reviews haven't been able to establish an association between saturated fat intake and heart disease, including a 2010 meta-analysis looking at 21 studies totalling more than 340,000 people.
It's true that certain saturated fatty acids have been reported to raise LDL cholesterol levels, including palmitic, myristic and lauric acid, which make up a large portion of milk fat. On the other hand, high-fat dairy has been shown to provide several cardioprotective benefits as well.
Therefore, although avoiding all dairy fat may lower LDL cholesterol, it may not be a good strategy for protecting heart health. (You can read more about health benefits of dairy in this post: Dairy on a Ketogenic Diet).
Moreover, it appears that the LDL cholesterol response to saturated fat intake is individualized, with some people experiencing an increase and others seeing little to no change.
Keto Diet App also says that it’s normal to be concerned if there LDL levels are raised, but thankfully there are several options to try to improve bad cholesterol as opposed to giving up on a low carb diet. It’s good to know there are options so you can continue to be on the keto diet and enjoy its many health benefits.
If your LDL cholesterol has significantly increased on a keto or low-carb diet, it's completely understandable if you're at least somewhat concerned. However, you might be reluctant to make any changes to your diet given the benefits you've experienced. On the other hand, you may decide that you want to try to lower your LDL values while still following a keto/low-carb lifestyle.
Although the long-chain omega-3 fatty acids found in fish typically reduce triglycerides more than LDL cholesterol, they're anti-inflammatory and may help protect against heart attacks.
Fiber, especially the soluble type, may be beneficial for heart health. It's been shown to help lower cholesterol levels, yet it doesn't seem to interfere with the absorption of fat-soluble vitamins and other nutrients.
Excellent keto-friendly sources of soluble fiber include avocado, blackberries, broccoli, brussels sprouts, and flaxseed.
Dave Feldman recently demonstrated that increasing net carb intake from 30 grams to 95 grams per day – (going from 4% of total calories to 13% of total calories) led to a significant drop in his LDL cholesterol level. Obviously, this level of carb intake isn't ketogenic; however, it is still moderately low carb. On the other hand, this will likely increase your blood sugar and insulin levels to some extent.
Eating about 50-60 grams of net carb daily (15-20 grams per meal) may be enough to help lower LDL without jeopardizing blood sugar and insulin stability.
At the time of writing this post, we're currently giving away free copies of the Body Reboot book because it's our mission to increase awareness and to help people lose weight and get healthy! If you help us cover the cost of shipping, we’ll send a copy to your door FREE. Go over to this page to see if there are any copies left.
Sources: Healthline, Very Well Fit, Diet Doctor, Ruled.me, International Journal of Cardiology 110.2 (2006): 212-216, Keto Diet App, The American Journal of Clinical Nutrition, Volume 91, Issue 3, 1 March 2010, Pages 535–546
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