MCT Oil: Does It Hack Your Health or Your Wallet?

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Blending MCT oil into the morning coffee

I feel lighter already...

It’s no secret that MCT (medium chain triglyceride) oil is a hot topic among the fitness and nutrition crowd. People are blending it in their coffee, cooking with it, and even taking tablespoons of it straight in hopes of gaining its magic benefits. Should you jump on the bandwagon or skip on it entirely? Read on to find out if the fat burning, brain boosting, and health promoting claims live up to the science.

MCTs gained popularity when the coconut oil craze hit and eventually gained “superfood” status among the paleo and low carb advocates. This so-called miracle oil has been ending up in the morning coffee of thousands of people and has risen to a multimillion dollar market on its own.

Medium chain triglycerides are a class of fats which are characterized by having a mid-length carbon chain structure and being fully saturated with hydrogen atoms. This means they are technically a saturated fat, but generally do not act in the body the same as longer chain fatty acids like as found in butter and animal fats. The three medium chain triglycerides that show up in supplements and some natural foods like coconut are caprylic, capric, and lauric acid, which are denoted as C8, C10, and C12, respectively, for the number of carbon atoms they contain.

                Due to their short carbon chain structure, capric and caprylic acid have the ability to be absorbed directly into the liver for use as energy via the portal vein in the intestines (1). Lauric acid acts in a more intermediate manner and is absorbed at a slower rate than the C8 and C10 MCTs and may be utilized in the body more like a long chain triglyceride (LCT). This property gives these fats the unique ability to bypass the typical digestive process of other dietary fats.

Due to these attributes, manufacturers and health gurus alike are promoting it as having the following beneficial effects:

1.       Increasing Fat Loss. Proponents say that MCT oil increases metabolism and helps you to burn more calories.

2.       Increased Ketone Production. MCT oil apparently is the best thing since starving yourself for getting your body into ketosis.

3.       Benefiting exercise performance. All of those circulating ketones are said to be a quick source of energy for those tough days at the gym.

4.       Better cognitive functioning. Speaking of ketones, this magic high-octane fuel is said to provide the brain with a better fuel source than glucose. Some even claim that it has the unique ability to provide relief to those stricken with Alzheimer’s disease.

5.       Antimicrobial properties. Natural health gurus claim that MCTs help fight off infection and maintain the beneficial bacteria found on and in our bodies.

6.       One of the best culinary oils. Everything from cooking to…you guessed it…a substitute for coffee creamer.

However, we don’t really like taking their word for it, so we decided to research it ourselves. Keep in mind that we don’t think rat studies are a good measure of human effect and can only serve as a stepping stone towards research with real people. Here’s what the science says.

Fat Loss

                The effect of MCTs on fat loss is mixed and appears to be dependent on the context of the diet in general. The research demonstrates that when subjects are given MCT oil, they experience a higher degree of beta oxidation (aka burning fat), but this is not entirely indicative of the utilization of stored body fat as an energy source (2-9). The input of a readily available fat source as energy will undoubtedly increase the amount of fat which is burned by cells. The novelty of this effect is that MCT’s have a propensity to be used for energy rather than be stored as fat. A common finding is that diets rich in MCT’s (around 80% of fat intake) have a tendency to enhance energy expenditure regardless of the number of calories consumed (2,3,5-9). It is unclear whether or not the increase in energy expenditure is due to more calories being utilized from stored fat or the MCT’s being used for energy rather than being stored in adipose tissue. However, there is a tendency for the groups of people consuming primarily MCT oil to lose more fat over time when compared with groups consuming primarily LCT oils, and this suggests an inherent thermogenic effect (2-4).

An interesting finding from three studies conducted on groups of lean women found that the degree of fat burning tapered off after about a week (5-7). The authors suggested that there may be compensatory mechanisms for the increases in energy expenditure and thermic effect of food that were measured. This may be due to the reduction in metabolic rate commonly seen with a caloric deficit. This same result was found in another study done on a group of overweight men, where the average energy expenditure and fat oxidation tapered off to an insignificant difference between the MCT and LCT oil groups (3). We should take into consideration that another confounding aspect may be due to the design of the studies. While the studies involved controlled feeding, they cannot take into account that subjects may “cheat” and consume extra food when not under supervision by the researchers. This may be a possible explanation for the MCT oil losing its thermogenic effects, but it is not known for sure.

We at least know that MCT oil rich diets can cause an increase in energy expenditure and may be partially protective against fat gain due to their unique metabolic features. The long-term effects appear to wash out over time, but as with any weight loss diet, a reduction in energy expenditure is inevitable and increased appetite may lead to overcompensation for the number of calories burned. This is another possible explanation aside from the subjects consuming calories outside of the study protocols, but until a specific mechanism is found, we can only speculate on why the increases in fat oxidation and energy expenditure appear to slow down.

*Note:* appetite also appears to be slightly reduced by consumption of MCT oil. This could be another possible reason as to why the MCT groups tend to lose more weight. Quite simply, eat less calories, lose more weight. Also, speculation about the potential confounding factors for fat loss is meant to help us understand that finding a fat loss effect isn’t always indicative that the supplement in question directly causes fat burning, but may be due to secondary effects.

Ketone Production

                Fortunately, the effect of MCT oil on blood ketone level is quite easy to measure and appears to be largely consistent across all research. Quite simply, give your subjects a dose of MCTs and measure the rise in ketones over the course of the next few hours and compare it to the rise from LCT’s. MCTs do appear to be greater than other fats at increasing ketone production (10), so you just might not have to starve yourself after all (enjoy our humor before furiously typing comments about ketogenic diets).

Benefiting Exercise Performance

                Testing the potential benefits of a supplement on exercise performance is no simple task. There are plenty of potential confounding factors like overall diet, sleep quality, unmatched groups of subjects, and even the ability of the athletes to experience an increase in performance regardless of the administration of the supplement. Not many studies exist on the impact of MCT oil on exercise performance, but they tend to tell us a few important things.

                First, MCT oil may have the potential to spare carbohydrate by increasing fat utilization during exercise and extending time to exhaustion, but this is not found in all studies on MCT and exercise (11-17). This is likely due to the increase in blood ketones experienced after consumption of MCTs which appear to be used as an energy substrate before carbohydrate metabolism kicks in. The athletes tested in a particular study (11) showed a decrease in glucose oxidation and an increase in fatty acid oxidation when a small amount of MCTs (6 grams) were consumed in a test meal prior to a bout of exercise, but the difference compared to LCTs was not significant. Compared to their performance with the same test meal with LCT in place of MCT, the MCTs appeared to increase their time to exhaustion significantly at a high rate of exertion at 80% VO2 max (11). The great part about this study is that the VO2 max scores did not differ between the two trials, and the test meals were exactly the same except for the type of fats being used.

                Second, despite the previously discussed study showing a slight increase in performance from MCTs consumed pre-exercise, other studies failed to show any significant difference in time to exhaustion (12-17). Yet, repeated dosing of MCTs during exercise appears to extend time to exhaustion, though we can’t rule out the simple effect of the calorie source itself extending exercise (as what tends to happen when you refuel with carbohydrate) and not being a unique attribute to MCT in particular (18).

                Third, there appears to be a reduction in blood lactate when MCTs are consumed pre-exercise which may play a role in extending time to exhaustion, yet individual difference in lactate clearance ability of the athlete in question needs to be taken into consideration (11). Since lactate buildup can halt exercise prematurely, and MCT oil appears to lower blood lactate levels, it would make theoretical sense that this may explain why some people experience an increase in performance. However, the variability in lactate clearance and whether or not the difference in lactate buildup is significant can mean that MCTs might offer nothing more than an extra fuel source during exercise. The research is too limited and variable in results at this time to make any definitive conclusions.

Better Cognitive Functioning

                This claim is very interesting. It goes by the premise that ketones are a better fuel source for the brain than glucose, and since MCT oil leads to an increase in blood ketones, the logic goes that MCT oil should improve cognitive functioning. However, the research on this subject isn’t so cut and dried. What we actually observe (and what these studies typically test) are the effects of the oil on those who already experience cognitive decline. This is a problem with most nootropic (brain booster) research. The beneficial effects seen in those with preexisting cognitive issues is extrapolated to people with health cognitive functioning, and that’s really no different with MCT oil.

                The studies available show a general trend towards cognitive improvement when individuals have a lower baseline cognitive ability (19-20). The proposed reason for which is due to the availability of a new energy source as ketones, where dementia patients tend to have a decline in the ability of the brain to utilize glucose as a fuel source. It should be noted that the treatment diets are typically ketogenic in nature (very low carb diets) and include a substantial portion of calories coming from MCT oil – usually over 50 grams per day.

                In terms of the cognitively healthy populations, MCT oil isn’t demonstrated to do much to improve cognitive performance, mainly because the research does not yet exist (as far as we looked). If one’s brain has the ability to metabolize glucose properly, then there isn’t evidence to support the claim that it boosts cognitive performance. An interesting study did find that in subjects with type 1 diabetes, MCT oil was able to mitigate some of the negative cognitive side effects associated with low blood sugar levels (21). What this shows us is that while MCT oil does not boost cognition per se, it can offer a non-glucose energy source that the brain can readily use when glucose is absent. This is practically relevant for those on a low carbohydrate intake who won’t have a steady stream of glucose to the brain, but it’s not likely to offer any downright improvement in cognition without a previously existing cognitive or glucose use disorder. This research is fairly new in this area, so we may see some validation of the general cognitive enhancement claim later on…your coffee will be waiting.

Antimicrobial Properties

This claim doesn’t get nearly as much air time as the rest, but I’ve definitely observed it in multiple places when reading about MCT oil. Many a health guru and blogger claim that MCT oil has the ability to help fight viral and bacterial infections. Not much research on this subject exists for the shorter chain (C8 and C10) fats, but tends to be focused around the C12 fat, lauric acid. Lauric acid appears to have antimicrobial properties when in contact with various pathogens like staphylococcus aureus and E. coli bacteria (22-24). The research appears to focus on preventing contamination of food products and the general efficacy of lauric acid vs. microbes. However, this does not mean that MCT oil has the innate ability to fight infections present in the human body (where cells themselves are infected in the case of viruses, or locations of infections not feasible for the lauric acid to reach). We have to remember that the limitations of these studies are that they are in vitro (meaning in a petri dish, not a live body).

A metabolite of lauric acid, monolaurin, has some demonstrated capacity against viruses, however, it has not been extensively investigated for actual treatment of infections. We should also take into consideration that since the majority of antimicrobial properties stem from lauric acid, if your primary goal is the antimicrobial action, you are better off going with either a lauric acid rich oil or just a straight coconut oil product. According to these studies and many more, lauric acid appears to be the most antimicrobial of all fatty acids (22-24).

Great Culinary Oil

                There is not much to say on this claim, but it should be noted that unless your MCT oil is high in lauric acid, you should not do much with it in terms of cooking (1). Caprylic and Capric acids both have low smoke points and should not be used to sauté or fry foods, but lauric acid holds a higher smoke point and may be used for light sautéing. MCT oil is best when used in lower heat baking applications, or as an addition to cold or room temperature condiments. If you’re going to pan fry or sauté foods and want MCTs in the final product, it would be more practical to use coconut oil since it will hold up better to the heat.

Other Considerations

                MCT oil looks like it can be a great addition to one’s diet (if you can afford its high price tag), but what really stands out is the high doses used in studies to obtain the beneficial effects. That should be noted by anyone who thinks that consuming miniscule amounts like a teaspoon or two per day will have much measurable effect. Plenty of the studies were finding only modestly significant effects at around 4 tablespoons per day, some in conjunction with a ketogenic diet, and often the exact composition of MCTs were not disclosed.

                If you’re taking MCTs to help with fat loss or raise your ketone levels, it appears that you’re in luck as long as you get the dosing right. MCTs appear to shine best when replacing other oils to help minimize fat gain. For exercise performance, you may or may not receive benefit, but it’s definitely worth trying out. Unless you have some preexisting cognitive decline or are on a low carb diet, MCTs might not offer you much benefit in terms of boosting brain power, but we really need more research to be certain. Get a lauric acid rich oil if you’re after the antimicrobial properties or if you’re looking to use plenty of heat on it with cooking.

                Ideally, I’d like to see more studies that are better designed to find certain effects. For fat loss, it appears we already have some decent research, but longer-term studies might help to shed some light on whether or not the thermogenic effects are short lived. Studies on exercise modalities other than cardio would be helpful in determining if there are any beneficial effects for sprinting and weight lifting. More studies that look at the potential for MCT oil to benefit cognitively healthy individuals would be beneficial as well so we can see if it helps as an actual nootropic or if it’s only beneficial to those with cognitive decline. As always in science, we need more research, even if it’s not practical to conduct.

                *Other note:* I originally meant to write in a small section on appetite suppression and realized that only after basically completing this evaluation. Anyway, looking to some of the fat loss studies (and additional studies not cited in the references, but conducted by some of the same researchers) point to a decent decrease in appetite with MCT oil when compared with LCT. I would be curious to see how that is affected after long term use of MCTs considering that the fat loss effect decreases over time (as the appetite suppression may as well). What appeared to happen most often is that a meal containing MCTs didn’t markedly reduce food consumption in a meal later on during the day, but preloading MCT reduced the consumption significantly. This is akin to drinking a beverage or having a light snack with MCTs about an hour before meals as a strategy to avoid overeating, but of course you still have to exert some level of psychological control over the morning donuts at the office.

Side Effects

                As noted in studies and in anecdotes available online, the most typical side effects are nausea, vomiting, and diarrhea. These are usually due to high amounts of MCTs being consumed rapidly, but it’s unclear if it’s due to the MCTs themselves or simply a higher fat intake from concentrated oil. It would be best to titrate your dose upwards in order to reach the minimal effective dose for your particular goals (and for the sake of your wallet). Overall, MCT oil appeared to be well tolerated in the studies we looked at. LD50’s (lethal dose for 50% of tested population) has been established in lab rats for isolated capric and caprylic acid, but it’s highly unlikely you’d be able to reach such a dose without violently spraying it out of both ends first. Perhaps one of the most notable side effects is the high cost of MCT oil. Achieving the doses used in the studies (about 4 tablespoons or ¼ cup per day) can get quite expensive over the long run.

Final Thoughts

                Is it worth trying out? If you can afford it and are looking for a good substitute oil, then it’s worth trying out if your goal is either fat loss or increasing ketone production. You could experiment and see whether or not it benefits you in any of the other areas, but currently there’s not much evidence to support most of the claims for the general population. I personally find that I feel slightly more energetic and that it’s a little easier to stay lean with MCTs or coconut vs. other oils. I definitely don’t hit the target doses, but my diet and exercise are also in check as well. I definitely prefer eating whole coconut over taking MCT oil, but I’ll use it in baked goods or on potatoes every now and then just to change things up.

If you're looking for another good coffee hack aside from MCT oil, I'd suggest a good mushroom supplement like lion's mane, chaga, or cordyceps. We really like the brand Four Sigmatic and stand 100% behind their products! You can follow this link to receive 10% off or click the banner below and use coupon code: hequals at checkout for 10% off all products!

                Let us know your thoughts and experiences with MCT oil in the comments below and be sure to check out our podcast episode on this topic on iTunes or Spotify. Be sure to like us on Facebook, follow us on Instagram, and subscribe to our mailing list for more content! Thanks for reading, and until next time, always remember that H = health!

References

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19.   http://www.sciencedirect.com/science/article/pii/S2214647415000021?via%3Dihub

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23.   Yang, D. et al. The antimicrobial activity of liposomal lauric acids against Propionibacterium acnes. Biomaterials. 2009 Oct;30(30):6035-40

24.   Khoramnia, A. et al. Improvement of medium chain fatty acid content and antimicrobial activity of coconut oil via solid state fermentation using a Malaysian Geotrichum Candidum. Biomed Res Int. 2013; 2013: 954542.