The Effect of Chronic Spice Consumption on Plasma Pro-Inflammatory Cytokine Levels and Monocyte Function in Adults with Overweight/Obesity

Abstract

Abstract Objectives Obesity-induced, chronic, low-grade inflammation is involved in the pathogenesis of cardiovascular disease (CVD). Numerous spices have anti-inflammatory properties in animal models and humans. However, few studies have examined the anti-inflammatory effect of spices in the context of daily meal consumption, which is typically how spices are consumed. The objective of this study was to investigate the anti-inflammatory effect of chronic spice consumption in adults with overweight/obesity at risk for CVD. Methods Nonsmoking adults (30–75 years old) with overweight/obesity (BMI ≥ 25 and ≤ 35 kg/m2), elevated waist circumference (≥94 cm for men and ≥ 80 cm for women) and at least one other risk factor for CVD were recruited for a 3-period, crossover, randomized controlled-feeding study (n = 63). In random order, participants consumed an Average American Diet (AAD) for 4 weeks containing: 1) 0.6 g of spice blend per 2100 kcal, 2) 3.2 g of spice blend per 2100 kcal, or 3) 6.4 g of spice blend per 2100 kcal with a≥2-week washout period between each test period. The spice blend was comprised of 24 popular spices. Blood was collected at baseline and after each test period. Peripheral blood mononuclear cells were isolated, and the % of monocyte subsets (classical; CD14++CD16−, intermediate; CD14++CD16+, non-classical; CD14+CD16++) were quantified using flow cytometry. Plasma pro-inflammatory cytokine levels (TNF-α, IL-1β, IL-6, IL-8, MCP-1) were measured using ELISA. In a subset of participants (n = 6), transendothelial migratory function of each monocyte subset through MCP-1 stimulated human umbilical vein endothelial cells was evaluated. Results Plasma IL-6 was significantly reduced after consuming the AAD containing 3.2 g compared to 0.6 g of spice blend in men and postmenopausal women (P = 0.031). Transendothelial migration of classical monocytes was significantly reduced following consumption of the AAD containing 3.2 g and 6.4 g of the spice blend compared to 0.6 g of spice blend (P = 0.011). Conclusions Consumption of an AAD with spices for 4 weeks attenuated inflammatory outcomes including plasma IL-6 and transendothelial migration of classical monocytes in adults with overweight/obesity. Funding Sources McCormick Science Institute.