A growing body of evidence highlights the close association between nutrition and human health. Fat is an essential macronutrient, and vegetable oils, such as palm oil, are widely used in the food industry and highly represented in the human diet. Palmitic acid, a saturated fatty acid, is the principal constituent of refined palm oil. In the last few decades, controversial studies have reported potential unhealthy effects of palm oil due to the high palmitic acid content. In this review we provide a concise and comprehensive update on the functional role of palm oil and palmitic acid in the development of obesity, type 2 diabetes mellitus, cardiovascular diseases and cancer. The atherogenic potential of palmitic acid and its stereospecific position in triacylglycerols are also discussed.

Obesity is a consequence of imbalance of food intake and energy expenditure that results in storage of energy as fat, primarily in adipose tissue. MicroRNAs are non-coding RNAs that regulate gene expression in metabolic pathways and they are also involved in fat-cell development. The aim of this study was to evaluate whether microRNA dysfunction contributes to obesity. We analyzed, by microarray, the expression profile of 1,458 microRNAs in subcutaneous adipose tissue (SAT) from nondiabetic severely obese (n = 20) and nonobese adults (n = 8). Among 42 differently expressed microRNAs, we confirmed by reverse-transcription PCR (RT-PCR) that miR-519d was overexpressed whereas the protein levels of peroxisome proliferator-activated receptor-α (PPARA) (a predicted miR 519d target) were lower, at western analysis, in severely obese vs. nonobese subjects. We also show that miR-519d specifically and dose-dependently suppressed translation of the PPARA protein, and increased lipid accumulation during preadipocyte differentiation. Because PPARA plays a central role in fatty acid homeostasis, and in the transcriptional regulation of genes that are necessary for maintenance of the redox balance during the oxidative catabolism of fatty acids, we suggest that PPARA loss and miR-519d overexpression could be associated with metabolic imbalance and subsequent adipocyte hypertrophy in SAT during obesity.

Objective: Adiponectin is an adipocytokine that exerts beneficial effects on obesity and related disorders by two receptors (ADIPORs). Adiponectin is produced as a monomer that circulates in serum as different oligomers. The oligomerization state and the tissue expression of adiponectin and ADIPORs are linked to its biological activities. In this study, the levels of total adiponectin and its oligomers were evaluated in relation to obesity and surgical weight loss. The expression of adiponectin and ADIPORs was analyzed in visceral and subcutaneous adipose tissues of obese patients. Design and methods: In 25 obese patients and 44 age-and sex-matched controls, the serum levels of adiponectin and its oligomers were measured and compared by ELISA, western blotting, and gel filtration. The expression of adiponectin and ADIPORs in both adipose tissues was evaluated by realtime quantitative PCR and western blotting. Results: The amount of each adiponectin oligomer, including the monomer, increases after weight loss. The reduced circulating levels of adiponectin and its oligomers are not associated with the adipose tissue depot-specific expression of adiponectin and ADIPORs. Conclusions: Our results suggest that in patients, adiposity is associated with the serum concentrations of adiponectin and its oligomers but not with adipose tissue depot-specific expression of adiponectin and ADIPORs. In particular, the increase in adiponectin monomer levels could probably be related to the improvement of the whole-body energy metabolism then being involved in the improvement of adipose tissue function after weight loss. This work indicates the importance of assessing the whole adiponectin oligomeric profile as further potential indicators of adipose tissue functions in obesity.