BACKGROUND/OBJECTIVES: Branched chain amino acids (BCAA) are among nutrients strongly linked with insulin sensitivity (IS) measures. We investigated the effects of a chronic increase of BCAA intake on IS in two groups of healthy subjects differing in their basal consumption of BCAA, that is, vegans and omnivores. SUBJECTS/METHODS: Eight vegans and eight matched omnivores (five men and three women in each group) received 15 g (women) or 20 g (men) of BCAA daily for 3 months. Anthropometry, blood analyses, glucose clamp, arginine test, subcutaneous abdominal adipose tissue (AT) and skeletal muscle (SM) biopsies (mRNA levels of selected metabolic markers, respiratory chain (RC) activity) were performed at baseline, after the intervention and after a 6 month wash-out period. RESULTS: Compared with omnivores, vegans had higher IS at baseline (GIR, glucose infusion rate: 9.6±2.4 vs 7.1±2.4 mg/kg/min, 95% CI for difference: 0.55 to 5.82) that declined after the intervention and returned to baseline values after the wash-out period (changes in GIR with 95% CI, 3-0 months: -1.64 [-2.5; -0.75] and 9-3 months: 1.65 [0.75; 2.54] mg/kg/min). No such change was observed in omnivores. In omnivores the intervention led to an increased expression of lipogenic genes (DGAT2, FASN, PPARγ, SCD1) in AT. SM RC activity increased in both groups. CONCLUSIONS: Negative impact of increased BCAA intake on IS was only detected in vegans, that is, subjects with low basal amino acids/BCAA intake, which appear to be unable to induce sufficient compensatory changes within AT and SM on a BCAA challenge.
- MeSH
- Anthropometry MeSH
- Exercise MeSH
- Diet, Vegan MeSH
- Diet MeSH
- Dietary Exposure adverse effects MeSH
- Dietary Proteins administration & dosage MeSH
- Adult MeSH
- Glucose Clamp Technique MeSH
- Insulin blood MeSH
- Insulin Resistance MeSH
- Muscle, Skeletal drug effects metabolism MeSH
- Blood Glucose metabolism MeSH
- Humans MeSH
- Young Adult MeSH
- Prospective Studies MeSH
- Surveys and Questionnaires MeSH
- Vegans * MeSH
- Amino Acids, Branched-Chain administration & dosage blood MeSH
- Dose-Response Relationship, Drug MeSH
- Check Tag
- Adult MeSH
- Humans MeSH
- Young Adult MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Publication type
- Meeting Abstract MeSH
- Publication type
- Meeting Abstract MeSH
- Publication type
- Meeting Abstract MeSH
- Publication type
- Meeting Abstract MeSH
- Publication type
- Meeting Abstract MeSH
