Changes

From Fellrnr.com, Running tips
Jump to: navigation, search

MCT

10,469 bytes added, 22:40, 8 January 2014
no edit summary
* MCT can produce nausea, vomiting, stomach cramps and diarrhea. Adaptation and mixing with other foods can reduce the problems.
* There are initial indications that MCT will reduce the symptoms of Alzheimer's and other memory problems.
{{Skeleton}}* MCT does not improve exercise performance.
=MCT and the Ketogenic Diet=
Because MCT will increase [[Ketones|Ketone Levels]] without needing [[Low Carbohydrate Diets| Carbohydrate restriction]], they are often used for [[Ketogenic Diets for Epilepsy| epilepsy treatment]]. Small amounts of MCT can be used to increase the ketone levels, or to reduce elevated cholesterol levels while on the Ketogenic Diet<ref name="Kossoff-2011-1809"/>. Larger amounts of MCT are the basis of the [[MCT Diet]], which allow for a greater carbohydrate intake than the traditional [[Ketogenic Ratio Diet]] and therefore more food choices.
Personally, I found that even after weeks of taking MCT, I could not consume it on its own without incurring dramatic digestive problems. Mixing MCT with other foods greatly reduced, but did not completely remove, the issues.
=MCT and Athletic Performance=
To followThe available evidence suggests that MCT most likely hinders athletic performance, probably because of digestive discomfort. ==Confounding Factors==The effect of MCT on exercise is not easy to study as there are many factors that might influence the outcome:* When is the MCT administered? MCT during exercise is likely to have a different result to MCT taken as part of a routine diet. * Are the subjects on a ketogenic diet? It seems reasonable that [[Ketoadaptation]] might change the effect of MCT. * How long is the trial? There are clear indications that adaptations occur over a period of some days that reduce the side effects of MCT consumption.* Are the subjects trained athletes or sedentary? Often trained subjects respond differently to their sedentary counterparts. * What intensity and duration of exercise is used? High intensity exercise usually burns more carbohydrate than fat.* How much MCT is consumed? * Is the MCT taken alone or with other fuels? Typically MCT in isolation causes far more digestive problems than when taken with other foods. Also, taking carbohydrate with MCT has been shown to reduce the levels of Ketones produced.* What is the MCT compared to? Is the MCT compared with the same calorie intake of another fuel, or to no calories?==Available Research==The table below summarizes the studies on the impact of MCT on exercise. {| class="wikitable"! Study! Subjects! MCT! Exercise! Result|-| Van Zyl-1996<ref name="Van Zyl-1996"/>| Trained| During exercise, subjects consumed two liters of * 10% CHO (C)* 4.3% MCT (M)* 10% CHO+4.3% MCT (CM)Total of 86g MCT| 2 h at 60% [[VO2max|V̇O<sub>2</sub>max]] plus simulated 40Km cycling time trail| While the time trial was slower with MCT than CHO, the combination of MCT+CHO was faster. This is the only study I found to show an improved performance with MCT.|-| Angus-2000<ref name="Angus-2000"/>| Trained| 250 ml/15 min of* 6% CHO (C)* 6% CHO + 4.2% MCT (CM)* placebo (P)| Simulated 100-km cycling time trial (~150 min, 35 kJ/kg)| Compared with P, C reduced time to exhaustion by 7% and CM by 5%.|-| Jeukendrup-1998<ref name="Jeukendrup-1998"/>| Trained| Either* 10% CHO (C)* 10% CHO + 5% MCT (CM)* 5% MCT (M)* Placebo (P)CHO was ~170g glucose, MCT was ~85g| 2 h cycling at 60% [[VO2max|V̇O<sub>2</sub>max]] plus 15 minute cycling time trail| The same performance for P, C, CM, but M impaired performance with 17-18% lower work rate. The lower performance with MCT was associated with gastrointestinal complaints.|-| Goedecke-2005<ref name="Goedecke-2005"/>| Trained| Either* 75g CHO prior + 200ml/20 min of 10% CHO* 32g MCT + prior + 200ml/20 min of 10% CHO + 4.3% MCT| 270 min cycling at 50% [[VO2max|V̇O<sub>2</sub>max]] interspersed with sprints every hour followed by a time trial | Hourly sprints and the time trial were slower with MCT. Half of the participants had GI problems with the MCT.|-| Goedecke-1999<ref name="Goedecke-1999"/>| Trained| 400ml at the start then 100ml/10mins of * 10% CHO (C)* 10% CHO + 1.72% MCT (LO-MCT)* 10% CHO +3.44% MCT (HI-MCT) | 2 h at 63% [[VO2max|V̇O<sub>2</sub>max]] plus simulated 40Km cycling time trail| No change in performance or difference in GI problems|-| Massicotte-1992<ref name="Massicotte-1992"/>| Untrained but fit (60.5 +/- 6.7 [[VO2max|V̇O<sub>2</sub>max]])| Either* 57g CHO * 25g MCT* PlaceboMCT and CHO were radiolabeled | 2 h cycling at 60% [[VO2max|V̇O<sub>2</sub>max]] | During exercise, 54% of the consumed CHO and 64% of the MCT were metabolized, contributed 7% (CHO) and 8.5% (MCT) of the energy expended. Both CHO and MCT maintained blood glucose levels better than the placebo.|-| Horowitz-2000<ref name="Horowitz-2000"/>| Trained| 1 hour before, either* 0.72 g/kg CHO (C)* 0.36 g/Kg MCT + 0.72 g/kg CHO (MC)MCT consumption was ~25g| 30 min cycling at 84% [[VO2max|V̇O<sub>2</sub>max]] | No change in muscle [[Glycogen]] levels, but the addition of MCT did increase glucose uptake at rest.|-| Jeukendrup-1996<ref name="Jeukendrup-1996"/>| Elite| 4 ml/kg at the start, then 2 ml/kg every 20 min of* 15% CHO* Isocalorific CHO+MCT, with 40% of calories from MCTSubjects consumed ~146g CHO or 87g CHO + 26.6g MCT| 90 min cycling at 57% [[VO2max|V̇O<sub>2</sub>max]], either after [[Glycogen]] depleting exercise the night before (LG) or not (HG).| Of the MCT ingested, 85% (LG) or 69% (HG) was metabolized during the 60- to 90-min period, contributing 7.6% (LG) and 6.5% (HG) to total energy in that period. |-| IvyCostill-2008<ref name="IvyCostill2008"/>| | Either* CHO (C)* CHO + MCT (CM)* CHO + LCT (CL)* Placebo (P)| 60 min cycling at 70% [[VO2max|V̇O<sub>2</sub>max]]| Energy from fat in C, CM and HypoglycemiaCL was similar (37-39%), but lower for P. There was no change in perceived exertion. |-| ÖöpikTimpmann2001<ref name="ÖöpikTimpmann2001"/>To Follow| Trained| MCT supplementation for 7 days as 34g/day in two doses, or placebo of cooking oil| Treadmill run to exhaustion at 80% [[VO2max|V̇O<sub>2</sub>max]]| There was a non-significant (10%) decline in time to exhaustion with MCT.|-| Décombaz-1983<ref name="Décombaz-1983"/>| | 240 calories of MCT or CHO consumed 1 hour before exercise| 60 min cycling at 60% [[VO2max|V̇O<sub>2</sub>max]]| Fat and carbohydrate metabolism were unchanged between the two conditions. |-| Sabatin-1987<ref name="Sabatin-1987"/>| Untrained| 1 hour before exercise, 400 Calories of either* CHO* MCT* LCT* Placebo (no calories)| Cycling at 60% [[VO2max|V̇O<sub>2</sub>max]] to exhaustion | No change in performance between nutrients. Of the consumed nutrients, 80% of CHO, 45% MCT and 9% LCT was metabolized.|-| Jeukendrup-1995<ref name="Jeukendrup-1995"/>| Trained| 4 ml/kg at the start, then 2 ml/kg every 20 min of* 15% CHO, 214 g (C)* Isocalorific 149 g CHO + 29 g MCT (CM-L)* 214 g CHO + 29g MCT (CM-H)* 29g MCT (M)| 180 min cycling at 57% [[VO2max|V̇O<sub>2</sub>max]]| During the second hour, 72% of the MCT was metabolized in CM-L compared with 33% in M. |}
=MCT and Alzheimer's=
There is evidence that MCT can help reduce peoples' memory impairment without carbohydrate restriction<ref name="RegerHenderson2004"/>. A study using elderly dogs showed a long lasting improvement in cognitive ability with MCT supplementation<ref name="PanLarson2010"/>. There are other anecdotal reports of MCT helping with Alzheimer's symptoms<ref name="www.tampabay.com"/>.
MCTs are sometimes recommended for weight loss. One study compared MCTs with Olive Oil and found a greater weight loss with MCTs<ref name="St-Onge-2008"/>. There is some evidence from an animal study that MCTs may be less palatable than other fats<ref name="Edens-1984"/>. However, an analysis of animal studies indicates that generally, replacing other fats with MCT does not reduce calorie intake<ref name="Bach-1996"/>. Based on my personal experiences with MCT, I would suspect that any weight loss benefit comes from the appetite reduction that comes from the associated nausea.
=MCT Safety=
MCT is considered safe at 1mg/Kg of body weight, and MCT has been shown as effectively non-toxic in high dose (9-12g/Kg) animal studies<ref name="TraulDriedger2000"/>.
=My Experiences with MCT=
* I've found that taking MCT on its own will often produce digestive problems, including nausea and apocalyptic diarrhea. Mixing MCT with other foods can reduce the problems, and I take MCT with cream or other foods.
<ref name="Edens-1984">NK. Edens, MI. Friedman, Response of normal and diabetic rats to increasing dietary medium-chain triglyceride content., J Nutr, volume 114, issue 3, pages 565-73, Mar 1984, PMID [http://www.ncbi.nlm.nih.gov/pubmed/6699737 6699737]</ref>
<ref name="Bach-1996">AC. Bach, Y. Ingenbleek, A. Frey, The usefulness of dietary medium-chain triglycerides in body weight control: fact or fancy?, J Lipid Res, volume 37, issue 4, pages 708-26, Apr 1996, PMID [http://www.ncbi.nlm.nih.gov/pubmed/8732772 8732772]</ref>
<ref name="Angus-2000">DJ. Angus, M. Hargreaves, J. Dancey, MA. Febbraio, Effect of carbohydrate or carbohydrate plus medium-chain triglyceride ingestion on cycling time trial performance., J Appl Physiol (1985), volume 88, issue 1, pages 113-9, Jan 2000, PMID [http://www.ncbi.nlm.nih.gov/pubmed/10642370 10642370]</ref>
<ref name="Jeukendrup-1998">AE. Jeukendrup, JJ. Thielen, AJ. Wagenmakers, F. Brouns, WH. Saris, Effect of medium-chain triacylglycerol and carbohydrate ingestion during exercise on substrate utilization and subsequent cycling performance., Am J Clin Nutr, volume 67, issue 3, pages 397-404, Mar 1998, PMID [http://www.ncbi.nlm.nih.gov/pubmed/9497182 9497182]</ref>
<ref name="Goedecke-2005"> JH. Goedecke, VR. Clark, TD. Noakes, EV. Lambert, The effects of medium-chain triacylglycerol and carbohydrate ingestion on ultra-endurance exercise performance., Int J Sport Nutr Exerc Metab, volume 15, issue 1, pages 15-27, Feb 2005, PMID [http://www.ncbi.nlm.nih.gov/pubmed/15902986 15902986]</ref>
<ref name="Goedecke-1999"> JH. Goedecke, R. Elmer-English, SC. Dennis, I. Schloss, TD. Noakes, EV. Lambert, Effects of medium-chain triaclyglycerol ingested with carbohydrate on metabolism and exercise performance., Int J Sport Nutr, volume 9, issue 1, pages 35-47, Mar 1999, PMID [http://www.ncbi.nlm.nih.gov/pubmed/10036340 10036340]</ref>
<ref name="Massicotte-1992"> D. Massicotte, F. Péronnet, GR. Brisson, C. Hillaire-Marcel, Oxidation of exogenous medium-chain free fatty acids during prolonged exercise: comparison with glucose., J Appl Physiol (1985), volume 73, issue 4, pages 1334-9, Oct 1992, PMID [http://www.ncbi.nlm.nih.gov/pubmed/1447077 1447077]</ref>
<ref name="Horowitz-2000"> JF. Horowitz, R. Mora-Rodriguez, LO. Byerley, EF. Coyle, Preexercise medium-chain triglyceride ingestion does not alter muscle glycogen use during exercise., J Appl Physiol (1985), volume 88, issue 1, pages 219-25, Jan 2000, PMID [http://www.ncbi.nlm.nih.gov/pubmed/10642384 10642384]</ref>
<ref name="Jeukendrup-1996"> AE. Jeukendrup, WH. Saris, R. Van Diesen, F. Brouns, AJ. Wagenmakers, Effect of endogenous carbohydrate availability on oral medium-chain triglyceride oxidation during prolonged exercise., J Appl Physiol (1985), volume 80, issue 3, pages 949-54, Mar 1996, PMID [http://www.ncbi.nlm.nih.gov/pubmed/8964761 8964761]</ref>
<ref name="IvyCostill2008">J. Ivy, D. Costill, W. Fink, E. Maglischo, Contribution of Medium and Long Chain Triglyceride Intake to Energy Metabolism During Prolonged Exercise, International Journal of Sports Medicine, volume 01, issue 01, 2008, pages 15–20, ISSN [http://www.worldcat.org/issn/0172-4622 0172-4622], doi [http://dx.doi.org/10.1055/s-2008-1034624 10.1055/s-2008-1034624]</ref>
<ref name="ÖöpikTimpmann2001">Vahur Ööpik, Saima Timpmann, Luule Medijainen, Harry Lemberg, Effects of daily medium-chain triglyceride ingestion on energy metabolism and endurance performance capacity in well-trained runners, Nutrition Research, volume 21, issue 8, 2001, pages 1125–1135, ISSN [http://www.worldcat.org/issn/02715317 02715317], doi [http://dx.doi.org/10.1016/S0271-5317(01)00319-0 10.1016/S0271-5317(01)00319-0]</ref>
<ref name="Décombaz-1983"> J. Décombaz, MJ. Arnaud, H. Milon, H. Moesch, G. Philippossian, AL. Thélin, H. Howald, Energy metabolism of medium-chain triglycerides versus carbohydrates during exercise., Eur J Appl Physiol Occup Physiol, volume 52, issue 1, pages 9-14, 1983, PMID [http://www.ncbi.nlm.nih.gov/pubmed/6360681 6360681]</ref>
<ref name="Sabatin-1987">Sabatin P, Portero GD, Bricout J, Guezennec CY. Metabolic and hormonal responses to lipid and carbohydrate diets during exercise in man. Med Sci Sports Exerc 1987;19:218-23</ref>
<ref name="Jeukendrup-1995">AE. Jeukendrup, WH. Saris, P. Schrauwen, F. Brouns, AJ. Wagenmakers, Metabolic availability of medium-chain triglycerides coingested with carbohydrates during prolonged exercise., J Appl Physiol (1985), volume 79, issue 3, pages 756-62, Sep 1995, PMID [http://www.ncbi.nlm.nih.gov/pubmed/8567514 8567514]</ref>
<ref name="Van Zyl-1996"> CG. Van Zyl, EV. Lambert, JA. Hawley, TD. Noakes, SC. Dennis, Effects of medium-chain triglyceride ingestion on fuel metabolism and cycling performance., J Appl Physiol (1985), volume 80, issue 6, pages 2217-25, Jun 1996, PMID [http://www.ncbi.nlm.nih.gov/pubmed/8806933 8806933]</ref>
<ref name="Kossoff-2011-1809">Eric. Kossoff, [http://www.amazon.com/Ketogenic-Diets-Eric-H-Kossoff/dp/1936303108 Ketogenic diets : treatments for epilepsy and other disorders], date 2011, publisher Demos Health, location New York, isbn 1-936303-10-8, Kindle Offset 1809</ref>
</references>
Retrieved from "http://fellrnr.com/wiki/Special:MobileDiff/4926"

Navigation menu