Green tea supplementation improves oxidative stress biomarkers and modulates IL-6 circulating levels in obese women

• Published in: Nutrición hospitalaria : organo oficial de la Sociedad Española de Nutrición Parenteral y Enteral Vol. 36; no. 3; pp. 583 - 588
• Main Authors: Noronha, Natália Yumi, Pinhel, Marcela Augusta De Souza, Nicoletti, Carolina Ferreira, Quinhoneiro, Driele Cristina Gomes, Pinhanelli, Vitor Caressato, Oliveira, Bruno Affonso Parenti, Cortes-Oliveira, Cristiana, Delfino, Heitor Bernardes Pereira, Wolf, Leticia Santana, Frantz, Fabiani Gai, Marchini, Júlio Sergio, Nonino, Carla Barbosa
• Format: Journal Article
• Language: English; Portuguese
• Published: Spain Grupo Arán 01.07.2019
• Subjects: Adult; Antioxidants - metabolism; Biomarkers - blood; Body Mass Index; Cytokines - blood; Dietary Supplements; Female; Humans; Interleukin-6 - blood; Malondialdehyde - blood; Middle Aged; Nutrition & Dietetics; Obesity - blood; Obesity - diet therapy; Oxidative Stress - drug effects; Tea; Young Adult; Té verde. Catequina. Estrés oxidativo. Inflamación. TEAC Malondialdehído. IL-6. Obesidad; Oxidative stress; Obesity; Té verde; Inflamación; Obesidad; Catechin; Inflammation; Malondialdehyde; IL-6; Catequina Estrés oxidativo; TEAC; TEAC Malondialdehído; Green tea
• ISSN: 0212-1611; 1699-5198; 1699-5198
• DOI: 10.20960/nh.2159

Introduction: obesity is associated with high levels of oxidative stress (OS) and inflammation. There is a lot of evidence that some polyphenols, such as green tea, have a positive impact on the OS state and consecutively, on inflammation. Objectives: the purposes of this study were: a) evaluate OS biomarkers in both obese and normal weight women; and b) evaluate if green tea supplementation has an impact on OS and inflammatory cytokine biomarkers of obese women. Methods: we evaluated obese (body mass index [BMI] ≥ 40 kg/m²) and normal weight (BMI between 18.5 and 24.9 kg/m²) women. Blood samples were used to access malondialdehyde (MDA), trolox equivalent antioxidant capacity (TEAC) and inflammatory cytokines. We randomly chose obese patients (18 individuals) and then gave them green tea supplementation for eight weeks. Statistical analysis included the Shapiro-Wilk, Wilcoxon, independent and paired t tests; p < 0.05 were considered as significant. Results: we enrolled 42 obese (BMI: 48.2 ± 9.3kg/m2) and 21 normal weight (BMI: 22.5 ± 2 kg/m2) women with an average age of 36.2 ± 9.1 years old. The serum levels of MDA were higher in obese (2.52 ± 0.31 µmol/l) than in eutrophic women (2.13 ± 0.26 µmol/l; p = 0.000). On the other hand, lower TEAC values were observed in the obese (0.75 ± 0.06 mM/l) than in the eutrophic group (0.78 ± 0.04 mM/l; p = 0.009). After the green tea intervention, MDA decreased 4.7% and TEAC increased 10%. Interleukin-6 (IL-6) serum levels decreased 12.7% after treatment (p = 0.03). Conclusions: a) the obese group had lower antioxidant capacity than eutrophic; and b) green tea supplementation ameliorated TEAC and MDA and reduced serum levels of IL-6 in obese women.