Article at a Glance
- MCT oil is often taken as an energy-boosting supplement that raises ketone levels, the source of energy the body uses when it burns fat instead of glucose.
- MCT oil is high in saturated fat. When combined with high doses of Vitamin D, use of MCT oil may increase the levels of calcium in the blood, especially in certain VDR genotypes.
- MCT oil has anti-fungal and antimicrobial properties that may cause a die-off reaction in those with compromised immune systems.
- Some common MCT oil side effects include fatigue, light-headedness, energy drops, increased heart rate, and diarrhea.
- MCT oil with high caprylic acid content is best for energy, while products that keep a higher ratio of lauric and capric acid provide better support for maintaining gut health.
- We like Brain Octane Oil for energy based on high levels of caprylic acid and Sports Research MCT for gut balance since it maintains about 31% lauric acid.
I originally wrote this post to highlight side effects of MCT oil that weren’t frequently discussed in other forums. Reading this post will give you all of that information, as well as the reasons some people may benefit from taking MCT oil, even if smaller doses is all they can handle.
Without removing the piece I wrote on side effects, I have added “update” sections throughout this post to give my current thinking on MCT oil, which is more positive in light of some research I’ve come across highlighting not only MCT oil’s energy production benefits, but also its potential as a natural antimicrobial and anti-fungal supplement that may help reduce harmful bacteria in the gut.
I currently take MCT oil in the form of Dave Asprey’s “Brain Octane” oil in low doses a few times a month for an energy boost. Taking it more often seems to increase my lipids to levels I don’t like, so this is a very occasional supplement for me.
In light of my VDR genotype, I try not to take vitamin D supplements alongside MCT oil. Aaron and I came up with a genetic hypothesis linking variants in the VDR genes to MCT oil sensitivity. Those of us with VDR “mutations” may want to avoid the combination of high IU doses of vitamin D with MCT oil, as the combo may increase serum calcium levels to uncomfortable levels. This is a theory we’re advancing based on our research, it is not yet proven. We lay out the details of that theory in this post titled VDR Fok1, Vitamin D, Fat and Heart Palpitations.
As MCTs are a product I now use on occasion, I had my staff do a review of some of Amazon’s top selling brands and come up with the best based on manufacturing process and ingredients.
OK, now on to the original post.
Ketones motivated my first MCT oil experiment
After listening to a number of podcasts devoted to the benefits of nutritional ketosis, and ketone bodies in general, and after reading resources like Dr. Peter Attia’s Eating Academy, I decided to experiment with MCT oil in the mornings. My normal dose was between 1/2 and a full tablespoon, which I usually added to a smoothie. For those of you who aren’t yet familiar, MCT oil stands for “medium chain triglycerides.” Advocates of ketogenic diets (basically a fancy new name for the Atkins diet) love MCT oil because it is a source of non-glucose derived energy for the body, and it ups your blood ketone levels.
This Bodybuilding.com article gives some nice background:
Many ketogenic diet and MCT oil spokespeople say that MCT’s energy sustaining powers can be explained as follows: when MCT oil is metabolized in the body, it behaves more like a carbohydrate than a fat. Remember that the fuel of preference for the body is carbohydrate. Unlike other fats, MCT oil does not go through the lymphatic system. Instead, it is transported directly to the liver where it is metabolized so it releases energy like a carbohydrate and creates lots of ketones (which can be used for fuel) in the process.
What are the benefits of MCT oil?
The MCT oil I used originally was comprised of 55% caprylic acid, 36% capric acid, and only 0.2% lauric acid. Initially, I saw the power of MCT oil and loved the benefits.
Small doses, of even 1-2 teaspoons, gave me a significant increase in brain function, and a burst of energy. I normally function at a fairly high level cognitively, but the MCTs gave me an “edge” that allowed me to maintain focus for longer periods of time.
My brain felt razor sharp.
MCT as an antimicrobial agent
Update: As I mentioned above, I am now taking MCT oil again, this time at a lower dose than before. I now find that cycling MCT oil usage gives me the greatest benefit as using small amounts everyday causes my body to adapt to the MCT, and I don’t get the same “pop” I get from irregular use. MCT oil’s antimicrobial benefits motivated my decision to use the supplement again.
Then, there is this study which shows that lauric acid and coconut oil reduced ammonia levels in cows. This study is of potential interest for those with genetic variants that have the potential to increase serum ammonia levels, namely urea cycle SNPs as well as CBS gene mutations. It is important to keep in mind that most MCT oil has the lauric acid removed, since lauric acid doesn’t function as an immediate energy source like caprlyic or capric acid does. If your goal is lauric acid, it’s better to just take a spoonful of coconut oil rather than resorting to MCTs.
Capric acid is a known anti-fungal agent, and has shown the ability to kill Candida in vitro (in test tubes). (R) In light of the antimicrobial and anti-fungal capabilities of capric and lauric acid, one of the causes of MCT oil side effects for some people could be an overload of toxins known as a “die off reaction.” Essentially, those with immune systems compromised by pathogens get flu like symptoms when the bad guys die off faster than their bodies can process the toxins.
MCT oil and the brain
While I, and many others, experience a noticeable cognitive boost from supplementing with MCTs, what about the medical literature? Are there studies which back up this effect?
I couldn’t find many (if you have some good ones please share in the comments).
There is this study which looked at the ability of MCT oil to increase ketones levels in the brain of Alzheimer’s patients as a way to make up for impaired glucose metabolism. The study found that MCT use doubled consumption of ketones in the brains of Alzheimer’s patients.
MCT oil side effects
Initially, over the course of a week’s worth of usage, with dosage never exceeding 1.5 tablespoons per day, I started to develop some side effects that temporarily made me stop using MCT oil.
I am a fan of Bulletproof Radio, Dave Asprey’s podcast, and have heard him extol the virtues of MCT products like the one he adds to Bulletproof coffee. Most of us have felt the surge of energy that comes from a morning of fasting, or just a light breakfast with protein. I figured a small dose of MCT oil would enhance this state, but over the course of a few days, I experienced episodes of fatigue, energy crashes, light headedness, increased heart rate, and on two occasions, minor heart palpitations. After first starting the regimen, I also experienced a mild version of what Dave Asprey likes to call “disaster pants,” which is a common MCT side effect.
You get the idea there.
More sensitive to heat
Bottom line is it felt to me like the MCT oil increased by body temperature as it built up in my system over time, making me more sensitive to heat, and causing my heart to beat hard when it normally wouldn’t (again likely caused by high >5,000 IU doses of Vitamin D). For a few days after stopping with MCT oil, I still felt light headed and noticed increased heart rate and overheating. It took a few days to get back to normal.
Update Note 4/30/18: I now believe this was caused by a combination of my VDR genes combined with high dose Vitamin D supplements that I took alongside the MCT oil. I have cut back some on vitamin D, although I still take it, but I seem to tolerate MCT oil much better when I cut down on my vitamin D IU dose, and when I take a smaller dose of MCT oil.
Potential lipid problems with MCTs
It’s wise to measure metrics like LDL-C, Lp(a), and LDL-P before and after taking MCT or before doing a Bulletproof style Paleo diet. Some won’t see any changes, but certain individuals will see a spike in LDL-P as the saturated fats in MCT retard LDL particle clearance through the liver.
For more see:
Forum accounts of MCT oil side effects
When you start digging around online, you come across a number of forum discussions with people reporting some of the issues with MCT use that I experienced. I’ve included links below.
Everyone’s body is different
It could be that some people do best staggering use of MCTs to once or twice a week to get benefits on those days, but avoid regular use so as not to trigger the side effects that come as making MCTs part of your daily routine. As with anything else, proper dosing is key.
It’s also important to have an idea of how your body will react to saturated fat from a lipid standpoint. New studies are teaching us that based on variability in LDL receptor activity due to mutations in genes like PCSK9, people respond very differently to high fat diets. Through our custom nutrition plans, we try to give clients an idea of what their likely genetic ability to clear LDL particle is. Lower clearance cautions in favor of a diet that is lower in the intense doses of saturated fats found in MCTs.
I now find that I tolerate MCTs quite well at lower doses and when I use on an occasional basis.