Current Research on Medium-Chain Triglyceride (MCT) Oils
MCT oils demonstrate clinical benefits in specific patient populations, with evidence supporting their use in parenteral nutrition formulations and potential applications for weight management and ketogenic diets.
Clinical Applications in Parenteral Nutrition
Benefits of MCT/LCT Mixtures
- LCT/MCT lipid emulsions show several advantages over traditional long-chain triglyceride (LCT) formulations alone 1:
- Improved nutritional status compared to solely LCT emulsions
- Better nitrogen balance in surgical cancer patients
- Less immunosuppressive effects and fewer clinical infections
- Lower incidence of intra-abdominal abscesses in malnourished surgical patients
- Improved mortality rates in non-cancer patients
- Better respiratory function in ICU patients on mechanical ventilation
Specific Benefits in Critical Care
- In ICU patients, LCT/MCT emulsions have demonstrated 1:
- Increased oxygen consumption (VO₂)
- Improved cardiac output
- Increased CO₂ production (VCO₂)
- Enhanced PaO₂/FiO₂ ratio compared to LCT emulsion alone
- Better reticular endothelial system function recovery in post-liver transplantation patients
Oncology Applications
- For cancer patients with cachexia requiring parenteral nutrition for extended periods 1:
- MCT oils are efficiently mobilized and utilized as a fuel source
- Higher lipid clearance rates observed in weight-losing cancer patients (2.1-3.5 g/kg/day) compared to healthy controls (1.4 g/kg/day)
- LCT/MCT emulsions show promising liver tolerance in long-term use
- A one-to-one fat-to-glucose energy ratio is recommended in cancer patients
Metabolic Effects and Weight Management
Weight Loss Applications
- MCT oil consumption leads to greater weight and fat mass loss compared to olive oil 2:
- In a 16-week study, MCT oil resulted in greater weight loss (-1.67 kg more than olive oil group)
- Lower endpoint trunk fat mass, total fat mass, and intraabdominal adipose tissue
- MCTs can be successfully incorporated into weight loss diets
Ketogenic Properties
- MCT oils demonstrate ketogenic effects that may benefit certain conditions 3, 4:
- Linear dose-response relationship between MCT intake and β-hydroxybutyrate (BHB) production
- MCT supplementation increases BHB levels compared to long-chain triglycerides
- May reduce symptoms associated with keto-induction when transitioning to ketogenic diets
- Potential applications in Alzheimer's disease prevention and treatment
Physiological Mechanisms
- MCTs have distinct metabolic properties compared to long-chain fatty acids 5:
- Rapidly oxidized in hepatic mitochondria
- Less likely to be stored in adipose tissue
- Do not produce "ectopic fat" metabolites that promote insulin resistance and inflammation
- Provoke a thermogenic response
- May be less obesogenic than comparable intakes of longer-chain oils
Clinical Considerations and Caveats
Individual Variability
- Notable individual variability exists in ketogenic response to MCT oils 3:
- Maximum BHB response to 42g MCT dose ranged from 0.4-2.1mM
- Variability in time to reach maximum BHB response
- Response affected by visceral fat, BMI, waist/hip ratio, and pre-test meal carbohydrate and protein content
Composition Considerations
- MCT composition varies among manufacturers with no clear definition 6:
- Originally included fatty acids from C6:0 to C12:0
- Modern commercial MCT products have varying compositions
- Lauric acid (C12)-rich MCTs (about 30%) are now available for cooking applications
Side Effects
- Potential adverse effects include 4:
- Abdominal pain (occurs with greater frequency and severity with MCT supplementation)
- Other keto-induction symptoms (though generally of lesser magnitude than with long-chain triglycerides)
Safety and Administration
- Intravenous MCT emulsions can be safely administered 1:
- Safe administration rate of 0.7-1.5 g/kg over 12-24 hours
- Current practice allows up to 2 g/kg/day in parenteral nutrition
MCT oils continue to be studied for various applications including obesity management, frailty prevention in the elderly, ketogenic diets for epilepsy and cancer patients, and potential cognitive benefits in dementia and mild cognitive impairment 6.