Medically reviewed by Dr. George Kosco, DO on October 26, 2021
For many people, a low carb diet not only makes weight loss possible, but also improves blood sugar, boosts energy and mental focus, and puts them in control of hunger.
However, when carbs decrease, dietary fat increases and this leads to questions about how a low carb or keto diet affects cholesterol. In this post, I share what the research has to say about the relationship and what you can do if you have high cholesterol on a low carb diet.
Low Carb Diets and Cholesterol – Summary
- With low carb or keto diets, when carbohydrate intake decreases, dietary fat intake increases
- When healthy whole foods make up a low carb diet, research shows reductions in total cholesterol, LDLs, and triglycerides, and an increase in HDL cholesterol
- Some individuals have a genetic propensity toward high cholesterol, particularly when their saturated fat intake is increased.
- To get a better overview of your cardiovascular risk, ask your doctor to go beyond the standard lipid profile and include HbA1c, hs-CRP, and NMR Lipoprotein tests.
- If you are looking for ways to tweak your diet to reduce cholesterol, you may want to reduce your fat intake while staying low carb.
- If you would prefer to stay keto or have a genetic propensity toward high cholesterol, you may want to lower your saturated fat intake.
What Does a Low Carb Diet Do to Cholesterol? [Video]
In this video, you’ll learn…
- Research on the links between cholesterol and low-carb diets.
- How to figure out if you have a genetic predisposition to high cholesterol.
- Diet changes that will help you reduce your cholesterol.
Going Lower Carb Means Higher Fat
Carbohydrates and fats are the two primary food nutrients that your body converts to energy. When you cut carbs, much of that lost energy source is made up for by increasing the amount of fat you eat. Some people take this to mean that you can eat as much butter and bacon as you want without consequences.
These foods can be a part of your diet. However, the dietary fats that make up a well-formulated low carb or keto diet come from a variety of animal and plant sources.
Research: Low Carb Diets and Cholesterol
When healthy whole foods make up a low carb diet, a meta-analysis of randomized controlled clinical trials showed that cholesterol profiles improve. These types of studies comb through the published scientific literature looking for patterns.
This makes them valuable because it helps to rise above any bias that could exist from a single study. What this meta-analysis found was that both low carb and low fat diets lowered weight and improved metabolic risk factors (1).
“Both diets also improved lipid profiles. Low-carbohydrate diets resulted in reductions in total cholesterol (−4.6 mg/dL), LDL cholesterol (−2.1 mg/dL), the ratio of total to HDL cholesterol (−0.7), and triglycerides (−30.4 mg/dL) and an increase in HDL cholesterol (4.5 mg/dL) from baseline to at least 6 months of follow-up.”
That is all very positive, and many people that reduce their carb intake are thrilled with how much their blood work improves. However, there is research that shows the opposite effect, meaning that LDL cholesterol increases when a lower carb, higher fat diet is followed (2).
Are You Genetically Prone to High Cholesterol?
Some individuals have a genetic propensity toward high cholesterol, particularly when their saturated fat intake is increased. If this is you, I realize that it is challenging when you try to improve your health by losing weight, only to be told that your reward is a recommendation to start taking statins for high cholesterol.
This blog post is in no way intended to take the place of your doctor’s advice or encourage you to ignore your past health history. The unfortunate truth is that many of us carry with us some damage that was caused by years of eating a poor diet, being overweight, and being stressed.
Those things from your past now require your doctor’s input. I cannot recommend the right path for you. However, I can share practical ways for you to gather clues about your health and research that you may want to read and possibly share with your healthcare provider.
One way that you can gather clues about how your body may handle a high-fat diet is by getting your genetic profile done. This sounds complicated, but you can do this on your own in the convenience of your home.
What you get for your effort is a look at your unique genetic makeup that reveals any genetic variations that are influenced by diet, such as having a propensity for saturated fats to increase your LDL cholesterol level.
Testing for a Genetic Link to High Cholesterol
There are two steps to the process of discovering if you have a genetic link to high cholesterol.
Step #1: Run your genetic profile using a service like 23andMe’s basic Ancestry + Traits Service.
Step #2: Download the raw data (i.e., text file (.txt) or data file (.csv)) from 23andMe and upload it to Dr. Rhonda Patrick’s website for analysis.
You will receive a full report detailing your unique genetic variations and the nutrition and lifestyle factors that impacts them.
Beyond Standard Cholesterol Tests
If you have not yet started your diet, it is advantageous to have your bloodwork taken before you cut carbs and then retest in a couple of months to track how your body is responding to your diet changes. However, bloodwork can be as beneficial for an experienced dieter as it is for a beginner.
If you have concerns about your cholesterol level, you can ask your doctor to go beyond the standard lipid profile and include tests for HbA1c and high-sensitivity CRP (hs-CRP). With this group of results, you’ll know your cholesterol level and your blood sugar and inflammation level. This will provide you with a more complete evaluation of your cardiovascular risk.
The components you want to be low are…
- total cholesterol
The marker that you want to be high is…
LDLs have been nicknamed the “bad cholesterol,” meaning they are thought of as the main culprits in cardiovascular disease. However, the research does not always support this notion. For instance, a review study found that high LDL cholesterol is inversely associated with mortality in older individuals (3).
If your LDL cholesterol increased with a keto or low carb diet, you have two options to pursue with your doctor. First, you can ask them to look at your positive bloodwork markers to evaluate your overall risk fully. Second, you can go one step further by asking for an additional blood test, known as an NMR lipoprotein test.
NMR Lipoprotein (NMR Lipid Panel) Test:
The blood test looks at the LDL particles circulating in your blood to determine how many there are and if they are mostly comprised of the small, dense, dangerous particles or the larger, less harmful ones (4) (5).
From research, we see that low carb or ketogenic diets have been associated with an increase in the size of LDL cholesterol particles, which is what you want for cardiovascular health (2).
Go Low Carb, Not Keto
If you are looking for ways to tweak your diet to reduce cholesterol, you may want to reduce your fat intake while staying low carb. With a keto diet, your fat intake typically remains above 70% of your daily calorie intake.
Many people find that following a low carb (not keto) diet allows them to lose weight and improve health. With this way of eating, your dietary fat intake can range from 50 to 60% of your daily calories.
Reduce Your Saturated Fat Intake
If you would prefer to stay keto or have a genetic propensity toward high cholesterol, you may want to lower your saturated fat intake. Many healthy foods are high in unsaturated fats, including avocados, raw nuts and seeds, fish, seafood, and healthy oils like avocado or olive oil.
By focusing on those foods and reducing saturated fat sources, such as butter, coconut oil, and animal and dairy fats, you may find that it positively influences your cholesterol profile (2).
Many people find that the benefits of following a low carb or keto diet go beyond weight loss to include improved bloodwork. However, you may have noticed that your cholesterol level increased when you started eating this way. If this is you, you can gather clues about what is going on by having your genetic profile done and looking at a broader range of bloodwork markers.
You may also want to tweak your diet to ensure that you are getting the right mix of nutrients for your body. If you’d like a guide to follow, you can learn about my low-carb and keto challenges through the links at the top of the website. With the 21-day low carb challenge, 20% of your daily calories come from carbohydrates and 60% from fat, allowing for a good mix of plant and animal foods. With the keto challenge, you’ll consume less than 10% of your daily calories from carbs and 70% from fat.
(1) Hu, Tian, et al. “Effects of low-carbohydrate diets versus low-fat diets on metabolic risk factors: a meta-analysis of randomized controlled clinical trials.” American journal of epidemiology 176.suppl_7 (2012): S44-S54.
(2) Kosinski, Christophe, and François R. Jornayvaz. “Effects of ketogenic diets on cardiovascular risk factors: evidence from animal and human studies.” Nutrients 9.5 (2017): 517.
(3) Ravnskov, Uffe, et al. “Lack of an association or an inverse association between low-density-lipoprotein cholesterol and mortality in the elderly: a systematic review.” BMJ open 6.6 (2016): e010401.
(4) Harada, P. H. N., A. O. Akinkuolie, and S. Mora. “Advanced lipoprotein testing: strengths and limitations.” Am Coll Cardiol https://www. acc. org/latest-in-cardiology/articles/2014/08/25/15/07/advanced-lipoprotein-testing-strengths-and-limitations. Accessed 27 (2019).
(5) El Harchaoui, Karim, et al. “Value of low-density lipoprotein particle number and size as predictors of coronary artery disease in apparently healthy men and women: the EPIC-Norfolk Prospective Population Study.” Journal of the American College of Cardiology 49.5 (2007): 547-553.
About the Author
Becky Gillaspy, DC graduated Summa Cum Laude with research honors from Palmer College of Chiropractic in 1991.