1. Introduction
obesity, tumor necrosis, TNF-α, inflammation, weight loss, injury or infection
OBESITY, INFLAMMATION, EVENTS, TUMOR NECROSIS
Previous trials have demonstrated that modifying dietary fat composition can influence the production of inflammation-related factors. Additionally, it has been suggested that not only the type of fat, but also the timing of fat intake can impact these factors. Therefore, the objective of the present study was to evaluate the effect of altering breakfast fat composition on inflammatory parameters. A 3-month crossover randomized trial was designed, involving 60 institutionalized women who alternately consumed a breakfast rich in polyunsaturated fatty acids (PUFA) (margarine), monounsaturated fatty acids (MUFA) (virgin olive oil), or saturated fatty acids (SFA) (butter), based on randomization. The following inflammatory markers were evaluated: epidermal growth factor (EGF), interferon (IFN)-α, interleukin (IL)-1α, IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor (TNF)-α, C-reactive protein (CRP), and vascular/endothelial growth factor (VEGF). The results showed that the most significant effects were observed with the high-MUFA breakfast, as there was a statistically significant decrease in plasma IL-6 (Although inflammation is a physiological process that helps maintain homeostasis after various stimuli, such as injury or infection [A pro-inflammatory program is activated early in adipose expansion and during obesity, continuously altering the immune system to a proinflammatory phenotype. This phenotype is characterized by the overexpression of proinflammatory cytokines, such as interleukin (IL)-1, IL-6, and tumor necrosis factor-α (TNF-α), along with other acute phase reactants, such as C-reactive protein (CRP), which exceeds the release of anti-inflammatory cytokines, such as IL-4 and IL-10 [Dietary fat, as the main component of cell membranes, has been proposed as a potential link between obesity development and cytokine production. In fact, membrane-derived fatty acids and other related compounds may promote or inhibit cytokine synthesis via the modulation of nuclear factor kappa-B (NF-κB) and/or peroxisome proliferator-activated receptor (PPAR)-γ/α [In agreement with these findings, previous observational studies have also shown that the Mediterranean diet, characterized by high MUFA acid intake, has been associated with a lower degree of inflammation biomarkers, as well as a protective role against cardiovascular events [Recently, new studies have focused not only on the quantity, but also on the time of nutrient intake [An interesting work by Jakubowicz et al. showed that simply modifying the energy intake at breakfast was enough to induce greater weight loss and waist circumference reduction in overweight/obese subjects [Therefore, the present work was conducted to elucidate whether changing the fat composition at breakfast can modify cytokine and other inflammatory marker synthesis. Through the present randomized crossover trial, we propose to identify the optimal breakfast fat composition for producing an improved profile of inflammatory markers in women.