Isoleucine has a regulatory effect on glucose transport and metabolism in the body and has been suggested to have a hypoglycemic (blood sugar lowering) effect when taken before glucose/carbohydrates. While this has been observed in animals,[1] human clinical trials so far have shown inconsistent results, and the clinical relevance of this effect is questionable.[2][3][4]
Alternatively, in vitro and animal studies suggest that BCAAs can induce insulin resistance[5] and that BCAA-restricted diets (especially isoleucine-restricted ones) can improve insulin sensitivity and weight status.[6][7] While some human observational data reports that increased consumption of BCAAs is associated with increased body mass index (BMI),[6] other research has found the opposite effect.[8][9] The long-term effects (both potentially positive and negative) of a BCAA-restricted diet in humans have been largely unexplored, and the few small and short-term trials that have been done have found inconclusive effects.[10][11]
References
- ^Ikehara O, Kawasaki N, Maezono K, Komatsu M, Konishi AAcute and chronic treatment of L-isoleucine ameliorates glucose metabolism in glucose-intolerant and diabetic mice.Biol Pharm Bull.(2008-Mar)
- ^Newmire DE, Rivas E, Deemer SE, Willoughby DS, Ben-Ezra VThe Impact of a Large Bolus Dose of l-leucine and l-isoleucine on Enteroendocrine and Pancreatic Hormones, and Glycemia in Healthy, Inactive Adults.Nutrients.(2019-Nov-04)
- ^Elovaris RA, Hajishafiee M, Ullrich SS, Fitzgerald PCE, Lange K, Horowitz M, Feinle-Bisset CIntragastric administration of leucine and isoleucine does not reduce the glycaemic response to, or slow gastric emptying of, a carbohydrate-containing drink in type 2 diabetes.Diabetes Res Clin Pract.(2021-Jan)
- ^Elovaris RA, Bitarafan V, Agah S, Ullrich SS, Lange K, Horowitz M, Feinle-Bisset CComparative Effects of the Branched-Chain Amino Acids, Leucine, Isoleucine and Valine, on Gastric Emptying, Plasma Glucose, C-Peptide and Glucagon in Healthy Men.Nutrients.(2021-May-11)
- ^Cholsoon Jang, Sungwhan F Oh, Shogo Wada, Glenn C Rowe, Laura Liu, Mun Chun Chan, James Rhee, Atsushi Hoshino, Boa Kim, Ayon Ibrahim, Luisa G Baca, Esl Kim, Chandra C Ghosh, Samir M Parikh, Aihua Jiang, Qingwei Chu, Daniel E Forman, Stewart H Lecker, Saikumari Krishnaiah, Joshua D Rabinowitz, Aalim M Weljie, Joseph A Baur, Dennis L Kasper, Zoltan AranyA branched-chain amino acid metabolite drives vascular fatty acid transport and causes insulin resistanceNat Med.(2016 Apr)
- ^Yu D, Richardson NE, Green CL, Spicer AB, Murphy ME, Flores V, Jang C, Kasza I, Nikodemova M, Wakai MH, Tomasiewicz JL, Yang SE, Miller BR, Pak HH, Brinkman JA, Rojas JM, Quinn WJ, Cheng EP, Konon EN, Haider LR, Finke M, Sonsalla M, Alexander CM, Rabinowitz JD, Baur JA, Malecki KC, Lamming DWThe adverse metabolic effects of branched-chain amino acids are mediated by isoleucine and valine.Cell Metab.(2021-May-04)
- ^Cummings NE, Williams EM, Kasza I, Konon EN, Schaid MD, Schmidt BA, Poudel C, Sherman DS, Yu D, Arriola Apelo SI, Cottrell SE, Geiger G, Barnes ME, Wisinski JA, Fenske RJ, Matkowskyj KA, Kimple ME, Alexander CM, Merrins MJ, Lamming DWRestoration of metabolic health by decreased consumption of branched-chain amino acids.J Physiol.(2018-Feb-15)
- ^Qin LQ, Xun P, Bujnowski D, Daviglus ML, Van Horn L, Stamler J, He K,Higher branched-chain amino acid intake is associated with a lower prevalence of being overweight or obese in middle-aged East Asian and Western adults.J Nutr.(2011-Feb)
- ^Li YC, Li Y, Liu LY, Chen Y, Zi TQ, Du SS, Jiang YS, Feng RN, Sun CHThe Ratio of Dietary Branched-Chain Amino Acids is Associated with a Lower Prevalence of Obesity in Young Northern Chinese Adults: An Internet-Based Cross-Sectional Study.Nutrients.(2015-Nov-18)
- ^Ramzan I, Taylor M, Phillips B, Wilkinson D, Smith K, Hession K, Idris I, Atherton PA Novel Dietary Intervention Reduces Circulatory Branched-Chain Amino Acids by 50%: A Pilot Study of Relevance for Obesity and Diabetes.Nutrients.(2020-Dec-30)
- ^Karusheva Y, Koessler T, Strassburger K, Markgraf D, Mastrototaro L, Jelenik T, Simon MC, Pesta D, Zaharia OP, Bódis K, Bärenz F, Schmoll D, Wolkersdorfer M, Tura A, Pacini G, Burkart V, Müssig K, Szendroedi J, Roden MShort-term dietary reduction of branched-chain amino acids reduces meal-induced insulin secretion and modifies microbiome composition in type 2 diabetes: a randomized controlled crossover trial.Am J Clin Nutr.(2019-Nov-01)