Efeito metabólico do consumo de óleo de palma interesterificado em camundongos C57BL/6 alimentados com dieta hiperlipídica

Abstract

Recent Brazilian legislation has restricted the use of trans fats in foods due to the consistent association between their consumption and an increased risk of cardiovascular diseases. As a result, the food industry has sought technological alternatives, leading to a significant increase in the use of interesterified palm oil (IPO) as a substitute for trans fats. In parallel, the consumption of ultra-processed foods (UPFs) has increased substantially, intensifying population exposure to industrially modified ingredients. However, the health impacts of IPO consumption remain poorly understood. The rising prevalence of obesity has been consistently associated with changes in dietary patterns, characterized by a high intake of UPFs. This dietary pattern is marked by high energy density and elevated levels of fats and simple carbohydrates, resulting in hyperlipidic and hypercaloric diets. In this context, the aim of this study was to evaluate the effects of interesterified palm oil consumption on the metabolism of C57BL/6 mice fed a high-fat diet. Sixty C57BL/6 mice were used and allocated into four groups (n = 15): Control (C), fed a standard AIN-93M diet; High-fat (HF), fed a high- fat diet rich in lard, with 50% of total energy derived from lipids; High-fat palm (HFP), fed a high-fat diet rich in palm oil; and High-fat interesterified palm oil (HFI), fed a high-fat diet rich in interesterified palm oil, both providing 50% of total energy from lipids. The experimental protocol lasted eight weeks. At the end of the experimental period, the HFI group exhibited greater body mass compared to the HF group (+11%, p < 0.05). This unfavorable metabolic profile was corroborated by the intraperitoneal insulin tolerance test (IPITT), in which the HFI group showed higher values than the HF group (+38%, p < 0.05), as well as by increased serum leptin concentrations (+22%, p < 0.05 vs. HF). In the oral glucose tolerance test (OGTT), the area under the curve (AUC) was significantly higher in the HFP and HFI groups compared to the HF group (+23%, p < 0.05). In addition, serum insulin concentrations were higher in the HFI group compared to the HFP (+13%, p < 0.05) and HF (+25%, p < 0.05) groups. Histological analysis of interscapular brown adipose tissue (iBAT) revealed alterations in cytoarchitecture, with evidence of whitening in all high-fat diet groups, along with reduced immunodensity of uncoupling protein 1 (UCP-1). Gene expression analysis in iBAT showed reduced expression of peroxisome proliferator-activated receptor gamma (PPAR-γ), PR domain-containing protein 16 (PRDM16), peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC- 1α), and UCP-1 in all high-fat diet groups, while the HFP group exhibited increased expression of inflammatory genes, including tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL- 6). Both the HFP and HFI groups presented hypertrophied adipocytes in epididymal white adipose tissue (eWAT), with increased mean adipocyte cross-sectional area, and all high-fat diet groups showed similarly elevated expression of inflammatory genes (TNF-α, IL-6, and interleukin-1 beta [IL-1β]). Additionally, the HFP and HFI groups exhibited hepatic and pancreatic steatosis associated with impaired insulin signaling. In conclusion, although similar metabolic alterations were observed with palm oil and interesterified palm oil consumption, the intake of interesterified palm oil induced more deleterious metabolic effects.