有在進行飲食管理的民眾一定有聽過「MCT油」，它到底是什麼？跟一般的油脂有何不同呢？

⭐什麼是 MCT？
MCT，英文全名為Medium Chain Triglyceride，中文名為「中鏈三酸甘油酯」是一種由中鏈脂肪酸所組成的飽和脂肪，一般俗稱為MCT油，經常被用來製作防彈咖啡。

日常生活中的食用油大多由LCFA長鏈脂肪酸 (Long-Chain Fatty Acids) 所組成，具有12 個以上的碳原子，通常稱作長鏈三酸甘油酯 LCT (Long-Chain Triglyceride) [1]，而MCFA中鏈脂肪酸 (Medium-chain fatty acids) 則具有6 - 12個碳原子[2]，所組成的油脂通常被稱作MCT (Medium Chain Triglyceride)。

MCT存在於許多天然食物中，例如椰子油、牛奶、起司等乳製品中，都有MCT的存在[3]。

 

 

⭐ MCT油與椰子油有何不同？ 

【椰子油】
椰子油是由椰子仁、椰子肉等製成，雖然其含有MCT，但除了 MCT 之外，椰子油還含有 LCT 和不飽和脂肪等。

【MCT油】
MCT油幾乎全由中鏈脂肪酸所組成，它是以椰子油或棕櫚油為基底，去除其他化合物並濃縮而製成的[4]。

 

⭐ MCT油為何更適合生酮飲食？ 

椰子油與MCT油因為受到執行「生酮飲食法」的人歡迎而受到矚目，生酮飲食(ketogenic diet)是一種食用高脂肪含量、低含量碳水化合物，適量蛋白質的飲食方法。[5]

高脂肪與低碳水化合物的飲食攝取，會使身體代謝脂肪而不是葡萄糖，並且產生酮體，使生理機能處於酮症狀態，而產生的酮體具有抑制食慾的作用，減少進食進而減低熱量攝取。

中鏈脂肪酸比例高的油脂適合做為生酮飲食中高脂肪食物，常聽到「防彈咖啡」代謝法，便是將具有高比例中鏈脂肪酸的油脂，加入咖啡中來幫助新陳代謝。

因為中鏈脂肪酸不像長鏈脂肪酸，需要較長時間經酵素或膽汁來消化和吸收[6]，中鏈脂肪酸通常能夠在消化後較快速的提供能量，且較少以脂肪形式儲存，[7]，相反的，多餘的長鏈脂肪酸較容易運送到脂肪組織儲存。

 

同樣都具有中鏈脂肪酸，為何MCT油比椰子油更適合生酮飲食呢？
椰子油雖然含有大量的中鏈脂肪酸，但實際上椰子油含有將近50%的長鏈脂肪酸，相比之下擁有高比例中鏈脂肪酸的MCT油更合適生酮飲食，因此，前期經常使用椰子油來調配的防彈咖啡，在後期也陸續採用MCT油做為中鏈脂肪酸的來源，椰子油則較常被用於烹飪，或用於美容保養等其他領域。

 

⭐整理 MCT油的3大益處

1. MCT油可以幫助飽足感
2. MCT油是良好能量能源
3. MCT可以促進新陳代謝
 
有多項研究表示，與椰子油和 LCT 相比，MCT 油更可以幫助促進新陳代謝和提供更大的飽足感 [8,9,10,11]。
 
參考資料：
(1) St-Onge MP, Bosarge A, Goree LL, Darnell B. Medium chain triglyceride oil consumption as part of a weight loss diet does not lead to an adverse metabolic profile when compared to olive oil. J Am Coll Nutr. 2008;27(5):547-552. doi:10.1080/07315724.2008.10719737
(2) Kris-Etherton PM, Fleming JA. Emerging nutrition science on fatty acids and cardiovascular disease: nutritionists' perspectives. Adv Nutr. 2015;6(3):326S-37S. Published 2015 May 15. doi:10.3945/an.114.006981
(3) Boateng, L., Ansong, R., Owusu, W. B., & Steiner-Asiedu, M. (2016). Coconut oil and palm oil's role in nutrition, health and national development: A review. Ghana medical journal, 50(3), 189–196.
(4) McCarty, M. F., & DiNicolantonio, J. J. (2016). Lauric acid-rich medium-chain triglycerides can substitute for other oils in cooking applications and may have limited pathogenicity. Open heart, 3(2), e000467. https://doi.org/10.1136/openhrt-2016-000467
(5) Masood W, Annamaraju P, Khan Suheb MZ, et al. Ketogenic Diet. [Updated 2023 Jun 16]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan. 
(6) Schönfeld, P., & Wojtczak, L. (2016). Short- and medium-chain fatty acids in energy metabolism: the cellular perspective. Journal of lipid research, 57(6), 943–954. https://doi.org/10.1194/jlr.R067629
(7) St-Onge, M. P., & Bosarge, A. (2008). Weight-loss diet that includes consumption of medium-chain triacylglycerol oil leads to a greater rate of weight and fat mass loss than does olive oil. The American journal of clinical nutrition, 87(3), 621–626. https://doi.org/10.1093/ajcn/87.3.621
(8) Kinsella, R., Maher, T., & Clegg, M. E. (2017). Coconut oil has less satiating properties than medium chain triglyceride oil. Physiology & behavior, 179, 422–426. https://doi.org/10.1016/j.physbeh.2017.07.007
(9) St-Onge, M. P., Mayrsohn, B., O'Keeffe, M., Kissileff, H. R., Choudhury, A. R., & Laferrère, B. (2014). Impact of medium and long chain triglycerides consumption on appetite and food intake in overweight men. European journal of clinical nutrition, 68(10), 1134–1140. https://doi.org/10.1038/ejcn.2014.145
(10) Maher, T., Sampson, A., Goslawska, M., Pangua-Irigaray, C., Shafat, A., & Clegg, M. E. (2019). Food Intake and Satiety Response after Medium-Chain Triglycerides Ingested as Solid or Liquid. Nutrients, 11(7), 1638. https://doi.org/10.3390/nu11071638
(11) St-Onge, M. P., & Jones, P. J. (2003). Greater rise in fat oxidation with medium-chain triglyceride consumption relative to long-chain triglyceride is associated with lower initial body weight and greater loss of subcutaneous adipose tissue. International journal of obesity and related metabolic disorders : journal of the International Association for the Study of Obesity, 27(12), 1565–1571. https://doi.org/10.1038/sj.ijo.0802467
(12) https://www.healthline.com/nutrition/mct-oil-vs-coconut-oil
(13) https://www.healthline.com/nutrition/mct-oil-benefits