Palm and interesterified palm oil-enhanced brown fat whitening contributes to metabolic dysfunction in C57BL/6J mice

•Palm and interesterified palm oils (PO and IPO) impair brown adipose tissue function.•PO and IPO consumption promotes fat accumulation and thermogenesis disruption.•Both PO and IPO lead to oxidative stress and inflammation in brown adipose tissue. Palm oil is widely used in the food industry owing to its high stability and versatility. The interesterified version has been used as an alternative to oils rich in trans fatty acids. However, the health effects of these vegetable oils are not yet fully understood. We hypothesized that the consumption of palm oil (noninteresterified and interesterified), even without excessive amounts of energy and lipids in the diet, could lead to morphofunctional changes in brown adipose tissue (BAT). To this end, male C57BL/6J mice were divided into 3 dietary groups (n = 10 each): soybean oil (SO), palm oil (PO), and interesterified palm oil (IPO) for 10 weeks. The PO and IPO groups had significant increases in the visceral fat mass and interscapular BAT (iBAT) lipid content. In iBAT, the PO and IPO groups showed lower mRNA expression of Ucp1, Adrb3, and Pgc1a, while the PO also showed lower mRNA levels of Ppara and Ampk, and the IPO showed lower Prdm16 expression. Moreover, PO had higher Il6 expression and lower catalase activity, while the IPO showed an upregulated Tnfa expression and lower catalase activity, but higher antioxidant activity of the glutathione peroxidase (GPx) enzyme. The consumption of PO and IPO had negative effects on weight and body fat, including the impairment of iBAT function. Our findings give rise to apprehensions regarding the safety and consequences of consuming PO and IPO for energy metabolism. Consumption of both unmodified and interesterified palm oil, even within an isocaloric diet, has been shown to negatively affect brown adipose tissue metabolism. This disruption may contribute to metabolic dysfunction, potentially impairing energy expenditure and fat utilization. iBAT, interscapular brown adipose tissue; PO, unmodified palm oil; IPO, interesterified palm oil; Il6, Interleukin 6; Ucp1, uncoupling protein 1; Adrβ3, β3-adrenergic receptor; Pdrm16, PR domain containing protein 16. [Display omitted]