Weight gain, but not macronutrient intake, modifies the effect of dietary branch chain amino acids on the risk of metabolic syndrome

Nutrients, Physical Activity, and Mitochondrial Dysfunction in the Setting of Metabolic Syndrome

Metabolic syndrome (MetS) is a cluster of metabolic risk factors for diabetes, coronary heart disease, non-alcoholic fatty liver disease, and some tumors. It includes insulin resistance, visceral adiposity, hypertension, and dyslipidemia. MetS is primarily linked to lipotoxicity, with ectopic fat deposition from fat storage exhaustion, more than obesity per se. Excessive intake of long-chain saturated fatty acid and sugar closely relates to lipotoxicity and MetS through several pathways, including toll-like receptor 4 activation, peroxisome proliferator-activated receptor-gamma regulation (PPARγ), sphingolipids remodeling, and protein kinase C activation. These mechanisms prompt mitochondrial dysfunction, which plays a key role in disrupting the metabolism of fatty acids and proteins and in developing insulin resistance. By contrast, the intake of monounsaturated, polyunsaturated, and medium-chain saturated (low-dose) fatty acids, as well as plant-based proteins and whey protein, favors an improvement in sphingolipid composition and metabolic profile. Along with dietary modification, regular exercises including aerobic, resistance, or combined training can target sphingolipid metabolism and improve mitochondrial function and MetS components. This review aimed to summarize the main dietary and biochemical aspects related to the physiopathology of MetS and its implications for mitochondrial machinery while discussing the potential role of diet and exercise in counteracting this complex clustering of metabolic dysfunctions.

Higher Intake of Total Dietary Essential Amino Acids Is Associated with a Lower Prevalence of Metabolic Syndrome among Korean Adults

We hypothesized that a well-balanced intake of total essential amino acids (EAAs) may be associated with lower prevalence of metabolic syndrome among Korean adults. This population-based cross-sectional study included 25,787 participants aged ≥30 years from the 2008-2019 Korea National Health and Nutrition Examination Survey. Dietary information was obtained from 24 h recall data. Demographic and lifestyle factors were assessed using self-administered questionnaires, and metabolic biomarkers were obtained from a health examination. Total essential amino acid score (EAAS) was calculated to determine whether essential amino acid (EAA) intake meets the recommended nutrient intake (RNI). Multivariable-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using logistic regression models. After adjusting for multiple confounding factors, participants with higher EAAS had a significantly lower prevalence of high blood pressure (OR: 0.86, 95% CI: 0.75-0.98), hypertriglyceridemia (OR: 0.86, 95% CI: 0.76-0.98), and Metabolic syndrome (MetS) (OR: 0.86, 95% CI: 0.74-0.996). Spline regression analysis confirmed linearity of the association between total EAAS and MetS. EAA intake and MetS are associated with an inverse dose-response relationship in which metabolic disease may be prevented when the overall EAA intake meets the RNI.

Food consumption of branched chain amino acids and insulin resistance: A systematic review of observational studies in humans

This review systematically investigated observational studies in humans that evaluated the dietary intake of branched-chain amino acids (BCAA) and its association with insulin resistance. A search implemented through the electronic databases of PubMed, Scopus, and Web of Science. The evaluation of insulin resistance or the risk of developing insulin resistance in humans were the variables of interest in the search for articles. After using the selection criteria, three studies included in this review. The Food Frequency Questionnaire (FFQ) was the instrument used to evaluate the diet in all of the selected studies. Overall, 1940 studies identified and three thoroughly reviewed. We found only one study with positive effects of BCAA on insulin resistance; the other two reviewed studies did not demonstrate positive effects of the dietary intake of BCAA, individually or the sum of three amino acids on variables of interest. In this sense, the associations between BCAA and insulin resistance are inconsistent, potentially due to other longitudinal outcomes.