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Is Bulletproof Coffee to blame for your high LDL?

Bulletproof Coffee High LDL Genetics

What is the current thinking on fat intake and LDL? Where does Bulletproof fit in?

In my previous post, I discussed fats, cholesterol, lipoproteins and their impact on heart health. For the better part of half a century a high dietary intake of saturated fat and cholesterol was identified as the major cause of heart disease, and a low saturated fat/cholesterol diet was promoted in the west.

Numerous studies have since identified weaknesses with this hypothesis, and as a result, in 2015 the USDA Dietary Guidelines Advisory Committee reversed the long-standing recommendation that people limit dietary cholesterol intake. (R) However, dietary cholesterol, as is found in eggs, is not necessarily the same thing as dietary saturated fat, as is found in butter.

Whilst the jury is still out on the relative risks and benefits of saturated or unsaturated fats, numerous diet plans have appeared proselytising the benefits of a high fat, low carb diet.

Nutritional ketosis

By virtually eliminating carbohydrate intake, the body enters a state of nutritional ketosis; whereby ketone bodies (derived from the breakdown of fat) rather than glucose (derived from carbohydrates) provide the majority of the bodies energy.

This state has been associated with positive outcomes such as weight loss, improvements in type 2 diabetes and numerous cognitive benefits (although there is no robust data backing up this particular claim). However, it has also been associated with negative impacts such as impaired kidney function and the development of osteoporosis (1,2).

A common association with these diets is replacement of long chain triglycerides with medium chain triglycerides (MCTs). Coconut, palm kernel oil and numerous dairy sources are key dietary sources of MCT, however many people use MCT oil supplements to maximise their intake. Indeed, John, in a previous post discusses his response to MCT oil supplementation.

What is Bulletproof Coffee?

Well before there was Bulletproof coffee, the Tibetans and other Himalayan cultures, drank Yak butter tea. (RBulletproof Coffee, as developed by David Asprey, is a spin off of this ancient Himalayan tradition.

The company is one of the major players in the “high fat (MCT), low carb” diet world, albeit in an extreme form. Bulletproof coffee is a cup of coffee made from “upgraded” beans and supplemented with 1-2 tablespoons of grass-fed (rather than corn fed) unsalted butter and 1-2 tablespoons of a proprietary MCT oil. The added fats, in the form of MCT and butter, increase the blood ketone levels of those who drink it.

Proponents claim that it delivers numerous health and cognitive benefits.

There is no science backing Bulletproof coffee as opposed to ketosis

However, whilst the benefits of nutritional ketosis in general have been investigated, the scientific merit of Bulletproof Coffee has not. That some people respond well is undeniable, but are there those who may be at risk from drinking what equates to several times the current recommended daily dose of saturated fat?

Well, as John reported in his post, he personally experienced some rather severe side-effects from an MCT supplement which included heart palpitations, an effect which has been described by several others:

We know that development of atherosclerotic plaques (depositions of associated lipids) on the blood vessel walls is major cause of heart disease, through narrowing blood vessels and potentially forming clots. It is unlikely that the rapid onset symptoms described above can be attributed to this, rather it is more likely an issue with electrolyte deficiency/balance in the blood caused by a sudden, large increase in dietary fat.

But could very high fat diets be having a longer term impact on heart health, and there those who may be at specific risk?

Bulletproof Coffee, hyperlipidaemia and LDL

An important question is what does following a “high fat, low carb” diet actually do to the levels of lipids in the blood?

Surprisingly, in a meta-analysis of several studies, blood triglyceride levels were decreased by an average 2.2 mg/mL, potentially as triglycerides are being broken down into ketone bodies rather than stored.

Cholesterol (0.9 mg/mL), LDL (0.5 mg/mL) and HDL (0.5 mg/mL) in comparison were all increased in those on high fat, low carb diets (3).

There is no data describing the effect of Bulletproof Coffee in a large population, however this report describes a patient presenting with hyperlipidaemia (elevated levels of lipids in the blood) after regularly using Bulletproof Coffee. Importantly, this man saw an increase in triglycerides, which were not elevated in those on more traditional ketogenic diets.

As I discuss in my previous post, cholesterol and triglycerides require packaging with lipoproteins in order to be transported through the circulatory system. I also discuss that the levels of cholesterol and triglycerides detected in the blood are not harmful of themselves, rather it is how and where these lipids are deposited around the body, a process mediated by lipoproteins.

See also our Lp(a) post.

LDL, and in particular a subset known as small dense LDL (sdLDL), are associated with the development of atherosclerotic plaques on the blood vessel walls. These plaques result in the narrowing of the blood vessels, and if ruptured can result in the rapid development of blood clots leading to a heart attack. HDL is thought of as protective, as rather than binding to blood vessel walls, it carries lipids to the liver where they can be broken down or excreted (4).

The meta-analysis of ketogenic diets show a clear benefit. Whilst LDL levels are increased, triglyceride levels are decreased, and HDL levels are increased, which is suggestive of a net benefit. However, for the person reporting hyperlipidaemia things are less clear. Whilst HDL is elevated, so too are LDL and triglyceride levels, which may point towards an increased risk of the development of atherosclerotic plaques.

It’s important to note here that this is just a single report, plenty of people report a beneficial effect from drinking Bulletproof Coffee, and lacking a large scale study we cannot draw conclusions as to what effect a high dose of saturated fats has on blood lipid and lipoprotein levels.

Anyone consuming Bulletproof coffee should be monitoring their lipid profiles to watch for spikes in metrics like LDL-P.

But, as I’m sure you can see those with alterations in LDL activity, or those with high baseline levels of LDL, may be at risk if they start on an excessively high fat diet as promoted by Bulletproof Coffee.

Are there any polymorphisms which may associate with elevated levels of LDL and risk of heart disease?

Genetic variants that might not do well on Bulletproof Coffee

To answer my previous question, the answer is yes. There are numerous polymorphisms which associate with increased levels of LDL.

SNP IDGene(s) of interest within or near associated intervalMajor allele, Minor allele (Risk)
C, T
C, T
G, T
C, T
C, A
C, G
G, T
C, T
T, C
T, C

Table adapted from:

Taken from my previous post, this table shows several polymorphisms that have an association with increased levels of LDL. Importantly, none were directly correlated with an increased risk of heart disease.

However, it is important to note that these studies were performed on normal populations, not ones supplementing their diet with very high levels of saturated fat. It remains unknown whether the risk alleles result in the production of more LDL regardless of lipid level, or if this would be altered when undertaking a high fat diet. Additionally, it is unknown if there are any functional differences in LDL associated with these polymorphisms which when in association with high blood triglyceride levels may prove harmful to heart health.

Short-term symptoms?

But in this instance we’re talking about longterm heart health, how can we fit the acute reports of a racing heartbeat or heart palpitations that some people report after taking MCT oil or drinking Bulletproof Coffee?

The short answer is, we don’t really know. But there are a couple of hypotheses we can make:

  • By replacing a “nutrient rich” balanced meal, with a high fat, but otherwise “nutrient poor” drink it is highly likely that the body is being deprived of key nutrients/minerals/vitamins etc.
  • As we’ve discussed previously vitamin D is key in regulating calcium uptake. As vitamin D is fat soluble, one possibility is that with increased levels of fat circulating in the bloodstream, there is a concurrent increase in vitamin D in the blood as well. This may in turn trigger a greater increase in calcium absorption, leading to a racing heart or heart palpitations.

Both these hypotheses are just that, and so should be taken with a pinch of salt. Until we can really understand the mechanism which is triggering this effect in some people, we can’t really investigate the possible mechanisms.

Supplements that lower LDL and Triglycerides

If a high fat diet can take some people’s lipid markers in the wrong direction, are there nutrients that can send these important metrics in the other direction? While there is evidence to indicate that nutraceuticals can lower LDL and triglycerides, it may be advisable for some to limit their dietary saturated fat intake.


For example, this study performed by the International Journal of Cardiology found that Bergamot reduced total cholesterol, LDL-C, and the LDL-C/HDL-C ratio in hyperlipidemic patients, compared to a control group. Adding Bergamot to the statin drug Rosuvastatin, significantly increased the efficacy of the statin.

See also: Citrus Bergamot: the all natural statin?


Berberine is another promising nutraceutical for both heart and gut health. This study found that oral administration of berberine for three months reduced total cholesterol, LDL-C and triglyceride levels significantly.

We would recommend taking a look at this excellent write up, by Dr. Jeffrey Dach, on the benefits berberine has shown in healing issues with leaky gut. Leaky gut can have an impact on heart health. (R)

Take-Home Message

It’s impossible to say whether Bulletproof Coffee is beneficial or harmful to health without proper large scale scientific studies. Whilst saturated fat and cholesterol may not be the bogeymen we thought they were, and should form part of a healthy balanced diet, the extreme dose associated with Bulletproof Coffee may be of concern.

Those who carry one or more of the risk alleles described above should consider careful monitoring of their blood lipid level before drinking Bulletproof Coffee, or consider less extreme ketogenic diets.

Please share your experiences in the comments section.

Aaron Gardner

Dr Aaron Gardner is a life-scientist with a strong background in genetics and medical research, and a particular interest in the developing fields of personalised medicine and nutrition.

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  1. Patti says:

    I’ve been drinking bullet coffee for about 2 years. I usually add 1 T + of MCT oil. I eat a moderate high fat diet and eat very few carbs, very little sugar. I just had some tests ran and my LDL is 135 and I also found out I have a 4/3 apoe gene. My doctor is telling me now to do the apoe
    Diet : 20% fat, 25% protein and 55% carbs. I’m so confused about the amount of carbs, especially the amount of grains and starches the apoe diet suggests? What are your thoughts on this? Thank you!

  2. Jeff says:

    So – the question I don’t see an answer to is “if I test high for total cholesterol after starting Bulletproof, will I see a drop in my numbers when I stop? and if so, approx how long should I wait to get retested?”


    • Hey Jeff, probably a question for your doctor, but if I was to weigh in, I’d say getting a blood draw on the heels of 3-4 week experiments makes sense. So eat Bulletproof for about a month, test, then go plant based for a month, retest.

  3. Kim says:

    Just got my lipid panel and I, too, saw a serious increase (almost 100 mg/dL increase) since I started drinking Bulletproof coffee (and I skip the MCT oil). I am now at 247 total cholesterol, although my HDL is on the high-end of good (77) and my triglycerides are fine (88). This would just be from all of the grass-fed butter!

  4. Jill says:

    I’ve just received my lipid profile results after finishing a bottle of bulletproof brain octane, using as instructed. My triglycerides went from 135 to 325. My hdl dropped to 44 from 63 and my total cholesterol increased to over 200 from 176.
    And, I never saw any positive results – no weight loss and no increase in brain function.

  5. Pat says:

    Hello, would you suggest taking bergamot at the same time as rosuvastatin or at a different time to that medication?

  6. Miles Bean says:

    Hi, I had my total cholesterol checked 03 October and it was 6.3 mol/l. Yes, high but not that bad considering that I have been on a hf/lc type eating for over 3 years. I decided to try bullet proof coffee and after 2 months had my cholesterol checked again. My readings were in the mixed hyperlipodaemic range. My total cholesterol has shot up to 8.5 mol/l with and my triglycerides were also very high. I for one was shocked and am now reconsidering which saturated fats are not working for me.

    • Hi Miles, thanks for sharing. That would fit as Bulletproof Coffee is a particularly extreme version of the high fat diet.

      Did you find any benefit from trying it? As I know most people who do, are coming from a “normal” diet, not switching up from a HF/LC diet as you describe.

  7. Dr. Alvin Berger (MS, Ph.D, Fellow, Prof) says:

    Interesting posts on MCTS and Bulletproof. I cannot comment directly for commercial reasons, but please check out Dr. SOS Nutrition Consulting on Facebook, and and numerous technical responses to customers questions on (under Thought these posts may be of interest to this site. I originally developed C8 KetoMCTs to treat my son’s type 1 diabetes, because I did not trust any commercial MCT products being sold-had to develop my own…

    • DR. Alvin, could you share your take on how the Bulletproof diet impacts lipid markers in some of your patients? Sounds like you might have a different point of view, which is welcome.

  8. Very informative post Aaron. I think Dave Asprey has done a great job with Bulletproof. I am definitely a fan of the podcast. Having said that, I’ve also had a number of conversations with friends, doctors and people on some nutrigenomic forums, all of whom have stories about major lipid problems when on the Bulletproof diet. Could be that the issue is user error and they’re not following the diet properly. More likely, it’s another example of one size fits all nutrition missing the mark.

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