RESUMO
BACKGROUND: Obesity is associated with low-grade inflammation and increased intestinal permeability (IP). The Brazil nut (BN) (Bertholletia excelsa H.B.K.) appears to be a promising dietary intervention to control inflammation by enhancing antioxidant defenses. OBJECTIVES: We aimed to assess the effect of daily BN consumption on inflammatory biomarkers and IP in the context of an energy-restricted intervention. Furthermore, we evaluated the correlation between the changes in these inflammatory markers and the changes in serum selenium and IP. METHODS: In this 8-wk nonrandomized controlled trial, 56 women with overweight or obesity were allocated into 2 groups, both following an energy-restricted diet (-500 kcal/d). The control group (CO) consumed a nut-free diet, while the BN group consumed 8 g BN/d, providing 347.2 µg selenium (Se). Inflammatory cytokines were analyzed in plasma and Se in serum. IP was assessed using the lactulose/mannitol test (LM ratio). RESULTS: Forty-six women completed the intervention. Both groups achieved similar energy restriction (CO Δ= -253.7 ± 169.4 kcal/d; BN Δ= -265.8 ± 141.8 kcal/d) and weight loss (CO Δ= -2.5 ± 0.5 kg; BN Δ= -3.5 ± 0.5 kg). The BN group showed lower values of C-reactive protein, tumor necrosis factor, interleukin (IL)1-ß, IL-8, percentage lactulose excretion, and LM ratio than the CO group. Additionally, changes in serum Se concentration were predictive of changes in IL-8 concentration (ß: -0.054; adjusted R2: 0.100; 95% confidence interval [CI]: -0.100; -0.007; P = 0.025), and changes in IL-8 were predictive of changes in the LM ratio (ß: 0.006; adjusted R2: 0.101; 95% CI: 0.001, 0.011; P = 0.024). CONCLUSIONS: Regular intake of BNs can be a promising complementary dietary strategy for controlling low-grade inflammation and improving IP in women with overweight/obesity undergoing energy-restricted treatment. However, the effects of BNs seem to be Se status-dependent. This trial was registered at the Brazilian Registry of Clinical Trials (ReBEC: https://ensaiosclinicos.gov.br/rg/RBR-3ntxrm/.