Fish oil contains the omega-3 fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) which are generally anti-inflammatory. Because of the importance of proper modulation of inflammation and immunity, fish oil is thought to offer a range of health benefits.
Fish oil might offer benefits for cardiovascular (heart) health,1, 2 although a recent Cochrane Review has noted little benefit for cardiovascular mortality overall.
Fish oil does, however, improve markers of cardiometabolic health, with clinically meaningful and statistically significant improvements in triglyceride (TG) levels,3, 4 and total cholesterol, with improvements in HDL (‘good’) cholesterol.5 Reviews also show a significant, positive role for fish oil supplementation at doses > 1000 mg for improved heart rate variability6 (a marker of lifestyle or fatigue induced systemic stress) and improved cardiac function and reduced markers of inflammation in heart failure patients.7, 8 There is also a significant effect from fish oil supplementation on blood pressure.9 However, aside from heart health, fish oil is likely to improve mortality outcomes in the critically ill,10 and reduce infectious complications.11, 12 For diabetes risk, there is a significant improvement in insulin sensitivity in those suffering at least one symptom of metabolic disorder.13 Fish oil has also been found to reduce the rate of relapse in Crohn’s Disease,14 and reduces depression scores.15 Both the fatty acids DHA and EPA might also be associated with anti-cancer activity in the body.16
Medium chain triglycerides or MCTs are a particular type of lipid (fat) that are slightly shorter than normal dietary fats. Most fats in the diet contain chains greater than 14 carbons long, whereas the MCTs are between 6 and 10 carbon chains long. This gives them the ability to escape the usual digestion pathway and go directly to the liver where they are converted into bio-available ketone fuels.17-23 These ‘ketone bodies’ (usually just called ‘ketones’) can be used as a preferred fuel by most tissues in the body, even brain cells!
If you’re following a ketogenic diet, MCTs can help you to achieve ketosis more easily and without having to restrict carbohydrate quite as much (making the diet easier to follow).24-26 Even if you’re not following a keto-diet, MCTs can increase how many calories you use,27 promote greater fat-burning and weight/fat-loss,28, 29 and reduce ‘belly fat’,30 compared to other types of fats. MCTs can also help us to stick to a healthy diet more easily, by reducing how much we want to eat!31, 32
MCTs also help to supplement the brain's normal reliance on glucose by providing ketones,33 and for this reason, MCT supplemented diets improve mental performance in those with Alzheimer’s Disease and other age-related cognitive decline.34, 35
The benefits of fish oil + MCT
While there isn’t much research directly examining fish oil and MCTs supplemented together, diets rich in MCT and omega-3 fatty acids reduce cholesterol, triglycerides, glucose, and uric acid in patients with metabolic disorder characterised by high levels of fat in the blood (hypertriglyceridemia).36, 37 Animal evidence suggests that MCTs might potentiate the immune and anti-inflammatory benefits of fish oil and increase the cardiovascular benefits over fish oil only supplementation.38, 39
Why should I take fish oil with MCTs?
There are many benefits from both MCTs and fish oil, so, it makes sense to combine them for a range of outcomes including potential protective effects for cardiovascular and metabolic health, reducing body fat, reductions in inflammation, and for providing a readily digestible and usable fuel source also high in the omega-3 fatty acids that many people do not get enough of day-in and day-out.
Of particular interest is the potential benefits of fish oil and MCTs for brain health and cognition. Fish oil plays a role in neural development and healthy functioning of the brain and central nervous system. They are also found in lower levels in erythrocyte membranes of patients with central nervous system disorders.40 Omega-3 fats from fish oil are also linked to reduced mental fatigue,41 improved memory,42 and cognition, along with reduced rates of depression and improved structural integrity of the brain.43, 44 Similarly, ketones are well known neuroprotective (brain protecting) and cognitive enhancing compounds. A single 20 g dose of MCTs has been shown to improve cognition.45
DHA in particular, the major essential fatty acid metabolites in the combination DHA-MCT formula produced by Melrose Health has many specific benefits. DHA makes up the majority of the polyunsaturated fat content of the brain and comprises over 50% of the plasma membrane of neurons. It is essential to the optimal functioning of many tissues throughout the body and supplementation is beneficial to the health of the heart, cardiovascular and brain function, and cognition and mood.46 Reviews of the many studies performed on DHA show:
- DHA, either alone or in combination with EPA (also from fish oil), is likely to improve sperm motility.47
- DHA improves cognition and behaviour in children.48
- DHA is likely to reduce cognitive decline.49
- DHA inhibits cell proliferation of a wide spectrum of cancer types.50
Both fish oil and MCT offer a range of benefits independently, and they might offer synergistic benefits for a range of outcomes, from brain health and cognition, through to cardiometabolic health, inflammation and immunity, and satiety and weight/fat-loss. The particular combination of DHA with MCT is likely to offer extensive benefits to brain health and function.
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2. León H, Shibata MC, Sivakumaran S, Dorgan M, Chatterley T, Tsuyuki RT. Effect of fish oil on arrhythmias and mortality: systematic review. BMJ. 2008;337.
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4. Eslick GD, Howe PRC, Smith C, Priest R, Bensoussan A. Benefits of fish oil supplementation in hyperlipidemia: a systematic review and meta-analysis. International Journal of Cardiology. 2009;136(1):4-16.
5. Zhu W, Dong C, Du H, Zhang H, Chen J, Hu X, et al. Effects of fish oil on serum lipid profile in dialysis patients: a systematic review and meta-analysis of randomized controlled trials. Lipids in Health and Disease. 2014;13(1):127.
6. Xin W, Wei W, Li X-Y. Short-term effects of fish-oil supplementation on heart rate variability in humans: a meta-analysis of randomized controlled trials. The American Journal of Clinical Nutrition. 2013;97(5):926-35.
7. Xin W, Wei W, Li X. Effects of fish oil supplementation on cardiac function in chronic heart failure: a meta-analysis of randomised controlled trials. Heart. 2012;98(22):1620-5.
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9. Campbell F, Dickinson HO, Critchley JA, Ford GA, Bradburn M. A systematic review of fish-oil supplements for the prevention and treatment of hypertension. European Journal of Preventive Cardiology. 2012;20(1):107-20.
10. Manzanares W, Dhaliwal R, Jurewitsch B, Stapleton RD, Jeejeebhoy KN, Heyland DK. Parenteral Fish Oil Lipid Emulsions in the Critically Ill. Journal of Parenteral and Enteral Nutrition. 2014;38(1):20-8.
11. Wei C, Hua J, Bin C, Klassen K. Impact of lipid emulsion containing fish oil on outcomes of surgical patients: Systematic review of randomized controlled trials from Europe and Asia. Nutrition. 2010;26(5):474-81.
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13. Gao H, Geng T, Huang T, Zhao Q. Fish oil supplementation and insulin sensitivity: a systematic review and meta-analysis. Lipids in Health and Disease. 2017;16(1):131.
14. Turner D, Shah PS, Steinhart AH, Zlotkin S, Griffiths AM. Maintenance of remission in inflammatory bowel disease using omega-3 fatty acids (fish oil): A systematic review and meta-analyses. Inflammatory Bowel Diseases. 2011;17(1):336-45.
15. He L, Li M-s, Lin M, Zhao T-y, Gao P. Effect of fish oil supplement in maintenance hemodialysis patients: a systematic review and meta-analysis of published randomized controlled trials. European Journal of Clinical Pharmacology. 2016;72(2):129-39.
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18. Yeh YY, Zee P. Relation of ketosis to metabolic changes induced by acute medium-chain triglyceride feeding in rats. The Journal of nutrition. 1976;106(1):58-67.
19. St-Onge M-P, Ross R, Parsons WD, Jones PJH. Medium-chain triglycerides increase energy expenditure and decrease adiposity in overweight men. Obes Res. 2003;11(3):395-402.
20. Mingrone G, Greco AV, Castagneto M, De Gaetano A, Tataranni PA, Raguso C. Kinetics and thermogenesis of medium-chain monocarboxylic and dicarboxylic acids in man: sebacate and medium-chain triglycerides. JPEN Journal Of Parenteral And Enteral Nutrition. 1993;17(3):257-64.
21. Jiang ZM, Zhang SY, Wang XR, Yang NF, Zhu Y, Wilmore D. A comparison of medium-chain and long-chain triglycerides in surgical patients. Annals Of Surgery. 1993;217(2):175-84.
22. Lai H, Chen W. Effects of medium-chain and long-chain triacylglycerols in pediatric surgical patients. Nutrition. 2000;16(6):401-6.
23. Sandström R, Hyltander A, Körner U, Lundholm K. Structured triglycerides were well tolerated and induced increased whole body fat oxidation compared with long-chain triglycerides in postoperative patients. JPEN Journal Of Parenteral And Enteral Nutrition. 1995;19(5):381-6.
24. Huttenlocher PR. Ketonemia and seizures: Metabolic and anticonvulsant effects of two ketogenic diets in childhood epilepsy. Pediatr Res. 1976;10(5):536-40.
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27. Dulloo AG, Fathi M, Mensi N, Girardier L. Twenty-four-hour energy expenditure and urinary catecholamines of humans consuming low-to-moderate amounts of medium-chain triglycerides: a dose-response study in a human respiratory chamber. Eur J Clin Nutr. 1996;50(3):152-8.
28. St-Onge M-P, Ross R, Parsons WD, Jones PJH. Medium-Chain Triglycerides Increase Energy Expenditure and Decrease Adiposity in Overweight Men. Obesity Research. 2003;11(3):395-402.
29. Tsuji H, Kasai M, Takeuchi H, Nakamura M, Okazaki M, Kondo K. Dietary Medium-Chain Triacylglycerols Suppress Accumulation of Body Fat in a Double-Blind, Controlled Trial in Healthy Men and Women. The Journal of Nutrition. 2001;131(11):2853-9.
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33. Henderson ST. Ketone Bodies as a Therapeutic for Alzheimer's Disease. Neurotherapeutics. 2008;5(3):470-80.
34. Reger MA, Henderson ST, Hale C, Cholerton B, Baker LD, Watson GS, et al. Effects of β-hydroxybutyrate on cognition in memory-impaired adults. Neurobiology of Aging. 2004;25(3):311-4.
35. Cunnane SC, Courchesne-Loyer A, St-Pierre V, Vandenberghe C, Pierotti T, Fortier M, et al. Can ketones compensate for deteriorating brain glucose uptake during aging? Implications for the risk and treatment of Alzheimer's disease. Annals of the New York Academy of Sciences. 2016;1367(1):12-20.
36. Hauenschild A, Bretzel RG, Schnell-Kretschmer H, Kloer HU, Hardt PD, Ewald N. Successful Treatment of Severe Hypertriglyceridemia with a Formula Diet Rich in Omega–3 Fatty Acids and Medium-Chain Triglycerides. Annals of Nutrition and Metabolism. 2010;56(3):170-5.
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43. O'Connor EM, Power SE, Fitzgerald GF, O'Toole PW. Fish-oil consumption is inversely correlated with depression and cognition decline in healthy Irish elderly adults. Proceedings of the Nutrition Society. 2012;71(OCE2):E151.
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47. Hosseini B, Nourmohamadi M, Hajipour S, Taghizadeh M, Asemi Z, Keshavarz SA, et al. The Effect of Omega-3 Fatty Acids, EPA, and/or DHA on Male Infertility: A Systematic Review and Meta-analysis. Journal of Dietary Supplements. 2018:1-12.
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