July 24, 2017 0 comments

Coconut oil: good for some, bad for others?

Updated July 27th, 2017

Must the Coconut Oil discussion be one size fits all?

Intro by John.

Hello everyone. Aaron and I decided to write this post in response to the renewed debate over the health merits of coconut oil after the American Heart Association warned against the dangers of its saturated fat content. The AHA says coconut oil is bad for your health.

But commentators we respect, such as Chris Kresser, vehemently disagree. I left this comment on Chris’ blog post Coconut Oil is Still Healthy, Despite AHA Claims.

I use coconut oil, mainly in homemade toothpaste and as a mouthwash, because as Chris points out, lauric and caprylic acid are both powerful antimicrobial agents. I do find the saturated fat and heart disease debate tiresome though as I think it’s likely that genetic polymorphisms are a major driver of how dietary fat affects us. There are numerous polymorphisms, such as rs515135, which associate with elevated LDL levels. The nutrigenomic data is still emerging, but I do believe a day will come soon when we can settle these debates based on genetics and simply say “saturated fat causes heart disease in some people, but not all people. If you have markers X, Y, Z exercise greater caution.”

Another reader, Mike Torres from Seattle, left this comment:

I’m concerned that the current debate is focused on whether coconut oil is healthy vs. not healthy, and not focused on the individual variations that might make something that’s healthy for one person, unhealthy for another – or vice versa.

Saturated fat – especially coconut oil – absolutely spikes my LDL-P (more than doubled) and Small LDL (more than tripled!) Could be because of the ACE gene (G/G) or some other gene associated with fat metabolism. But it’s testable and repeatable. So regardless of the AHA’s motivations, I don’t think it’s accurate to say any one thing is healthy or not on a broad scale vs. speaking in individual terms.

We couldn’t agree more with Mike!

This post is offered as a middle road to the black and white discussions surrounding coconut oil. The reality is that Coconut Oil is probably good for some, and probably very bad for others.

For example, genetic polymorphisms associated with higher LDL levels may want to avoid coconut oil and limit saturated fat intake. Others may benefit from its readily available fat energy, or from its antimocrobial properties.

Just my two cents, but based on what I’ve seen anecdotally around the web, I think the marketing of coconut products has far outpaced its health benefits. There are a growing number of people whose lipid markers are looking pretty scary on the Bulletproof Diet.

Now passing the mic to Aaron for the meat of the post.

Thanks, John. Now on to the merits of coconut oil.

 

Are Coconut oil supplements really healthy?

Alongside the flavor benefits of coconuts as a delicious food, and yes they are delicious, no one is disputing that, the raft of specific health claims attributed to coconuts in recent years have been on the rise. Bulletproof Coffee and its MCT oil is a great example.

Whilst some, such as claims of more efficient hydration, are relatively harmless, other claims have potentially wider reaching implications for individual and population health; hence the recent American Heart Association report. Below, I’ll run down the various uses for coconut oil and weigh in on whether there is reason to say it is healthy.

Oral hygiene – definitely healthy

Coconut oil has been used for generations in Aryuvedic traditions as tool for maintaining oral health. The practice, known as pulling, involves swirling coconut oil in the mouth, sometime for as long as 30 minutes. Pulling is usually done in the mornings. Turns out there is a science based reason for using coconut oil in this way as the lauric acid found in coconut oil has been proven in multiple studies to have a potent antimicrobial effect.

Mental acuity – possibly healthy for some, efficacy questionable

Coconut oil contains a form of fat known as medium chain triglyceride or “MCT.” The two major benefits attributed to MCTs, and therefore coconut oils and fats, are:

  1. the promotion of fat burning and;
  2. mental sharpness.

MCTs have been shown to increase energy expenditure and decrease weight gain (or promote weight loss) when compared to long chain triglycerides (LCT) such as olive oil (R,R).

The increase in mental sharpness is thought to occur through the increase of ketone bodies. By eating a high fat, adequate protein and low carbohydrate diet, fats rather than carbohydrates are preferentially used to provide energy. When your body burns fat instead of glucose, you are in a state of ketosis. By preferentially burning fats, it is claimed that the sleepy feeling generated following eating a meal rich in carbohydrates is avoided, allowing greater focus as well as myriad other health benefits.

Ketogenic diets have evidence of health benefits

There is a lot of evidence that ketogenic diets can have a beneficial effect, having historically been used in the treatment of childhood epilepsy (R). There is even evidence that ketone bodies can be protective against radiation. (R)

More recently MCTs have been proposed as an aid to achieving a state of ketosis. They are marketed as an ideal source of fat energy due to their easier absorption and use than other dietary fat sources (R,R).

As coconuts are rich in MCT’s, they have become a preferred source of fat for this type of diet. It is therefore easy to see how a link towards improved mental acuity could be attributed to coconut oil.

Coconut oil is not MCT oil

However, the evidence for some of these claims is less than stellar. A series of papers from researchers at Cornell UMS are frequently cited to demonstrate the fat burning benefits of MCTs and therefore coconuts (R). These studies do indeed show a marked effect on weight loss in overweight populations when LCTs such as olive oil were replaced with 100% pure MCT oils (R,R).

While MCT oil is made by refining coconut oil, they are not the same product. Coconut oil does not contain 100% MCTs, rather it is thought to comprise of approximately 14% MCTs with the rest made up more traditional LCTs and carbohydrates (R). One of the authors of the papers themselves have even gone on record to state that:

“From what I can tell, my research is being used to say that coconut oil is healthy, but this is a very liberal extrapolation of what we’ve actually studied… We don’t know if the amount in coconut oil is sufficient to have similar effects as pure MCT oil in releasing energy expenditure and improving satiety and weight management.”

Image From St-Onge et al. Medium-Chain Triglycerides Increase Energy Expenditure and Decrease Adiposity in Overweight Men. Obesity Research. 2003. Figure one shows an increase in energy expenditure when an MCT rich diet (black squares) is used compared to a normal olive oil rich diet (white squares), at both 2 and 28 days. A similar increase in fat oxidation is shown in figure 2 at both 2 and 28 days.

Bottom line here is that MCT oil was found to have health benefits that cannot, and should not be extended to coconut oil. And before you run off and include MCT supplements in your diet, remember they are even higher in saturated fat content than is coconut oil.

Coconut oil and heart health – unhealthy for some

For those using coconut oil as stable cooking oil, or taking a few tablespoons with their coffee, whether their coconut oil usage can be said to be healthy depends on the state of their lipid profile. As Mike from Seattle points out above, certain people experience dangerous spikes in LDL and other heart disease markers whilst on a diet high in saturated fat, and coconut oil is high in saturated fat.

Coconut oil increases HDL, but also LDL and Triglycerides

Coconut oil diets have been shown to increase the levels of triglycerides, HDL cholesterol and LDL cholesterol in the blood (R).

See also: Citrus bergamot: the all natural statin?

The importance of this is unclear; as I have previously discussed, it is thought that the actual levels in the blood are less important that the ratios of all three together. However, for those with a heightened cardiovascular risk, the presence of increased blood triglycerides and LDL, through either genetic or environmental factors, then this is less than desirable. Indeed, the British Nutrition Foundation state that there are no health benefits associated with a dietary intake of coconut oil, when compared to other healthier oils such as olive oil (R).

Your genetics and cardiovascular risk

There are several SNPs in distinct genes which are associated with poor cardiac outcomes. Carriers of these SNPs may therefore want to carefully consider the pros and cons of coconut oil dietary supplementation due to its ability to raise LDL and triglycerides:

ADIPOQ

Adiponectin encoded for by the ADIPOQ gene is a protein hormone with a major role in regulating fat storage and metabolism. High circulating levels are associated with positive health benefits, whereas conversely low levels or reduced activity are associated with an increased cardiovascular risk, or risk of developing type 2 diabetes (T2D) (R).

The risk ‘C’ allele in ADIPOQ T16627C (rs17366743) is associated with reduced adiponectin activity and an increased T2D risk. Interestingly, two other SNPs are flagged in the same study rs17300539 and rs6773957, which commonly appear as being linked with an increased risk, but the authors actually associate no effect with these SNPs (R).

ACE

Angiotensin I Converting Enzyme, encoded for by the ACE gene is an enzyme which plays a key role in regulating blood pressure, and so is important in maintaining cardiovascular health (R). ACE converts the inactive angiotensin I into its active form angiotensin II which is a potent vaso-constrictor, and can also degrade vaso-dilators; therefore increased ACE activity is often associated with increased blood pressure (R,R). The risk ‘G’ allele of G2328A (rs4343) is associated with increased ACE activity, and increased blood pressure during exercise, putting them at a greater cardiovascular risk (R,R). Carriers may therefore wish to avoid MCTs or other saturated fats, to avoid increasing their risk further.

However all is not bad news for those carrying the ‘G’ allele as some studies have shown that carriers may perform better at sports requiring short bursts of activity such as sprinting due to alterations in heart structure (R).

APOE

Apolipoprotein E, encoded for by the APOE gene transports lipoproteins (LDL, HDL etc..), vitamins and cholesterol around the body (R). Two SNPs within APOE interact to promote cardiovascular risk; the ‘T’ allele of C526CT (rs7412) and the ‘T’ allele of T388C (rs429358) (R). Together these risk alleles promote an accumulation of dietary fat in the blood by limiting the interactions between Apolipoprotein E and its receptors (R,R). Therefore, diets which promote an increased level of dietary fat should be avoided.

NOS3

Nitric oxide synthase 3, encoded for by the NOS3 gene is an enzyme which is responsible for the production of the small molecule nitric oxide (NO). NO is important for cardiovascular health as it acts as a vasodilator, and so alter blood pressure, and also strongly inhibits the formation of blood clots (R,R). Two SNPs in NOS3 are associated with poor health outcomes; the ‘G’ allele of G51-898A (rs1800779) or the ‘A’ allele of A-52+1009T (rs1800783) (R,R). The exact mechanism for each is unknown however in both instances raised blood pressure and other cardiovascular risk markers are observed.

VDR

This one is a little bit more out there, but fits well with John’s experience with MCT supplementation. The vitamin D receptor encoded for by the VDR gene, as it name would suggest, acts as the cellular receptor for vitamin D. In individuals with a certain combination of VDR SNPs (it’s complicated and covered in more detail in our post here), vitamin D supplementation coupled with high dose MCT supplementation may lead to issues such as a racing heart beat or heart palpitations.

Take home message

So, bearing in mind the AHA report what should you do?

Well it’s important to re-state that coconuts are not a miracle food, but nor are they a food villain. As for dietary or supplement advice it depends on your current lifestyle, diet and underlying genetics.

It’s best to discuss with your doctor once your baseline lipid markers are known. The message here is that there are many variables that go into whether coconut products are healthy for a given individual. If you’re genetically predisposed to elevated LDL levels, coconut oil supplements probably aren’t a great choice.

If you have healthy LDL levels and testing shows you maintain them with ease, coconut oil or MCT oil in moderation could provide a nice mental boost without impacting heart health.

We encourage readers to test and experiment. Know your numbers and know your genetic risk. Then make the decision that is right for you based on all the evidence.

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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