Moderated-fat Diet Complemented With Green Tea Reduces oxLDL and Fat Mass in Obese Women (GTRoxLDL)

Moderated-fat Diet Complemented With Green Tea Reduces oxLDL and Fat Mass in Obese Women: A Randomized, Controlled Clinical Trial

Background: Obesity is a chronic degenerative disease, considered as cardiovascular risk factor, characterized by systemic inflammation and high levels of oxLDL. Clinical studies have suggested that drink green tea could improve these complications. Objective: Analyze the effect of a moderate-fat diet complemented with green tea on oxLDL, fat mass and TNFa in obese women. Design: Randomized, controlled clinical trial. Obese women, without other chronic-degenerative disease were divided using a computer-generated random sequence: control group (CON) with n=32, and intervention group (INT) with n=32; and were instructed to consume a moderate-fat diet, and INT group was instructed to complement the diet with green tea. Anthropometric and biochemical measurements were performed, and oxLDL and TNFa s levels were determined by ELISA. All parameters were realized at baseline and in the 1st, 2nd and 3rd months post-intervention. TNFa mRNA expression was determined by real-time RT-PCR (basal and final). The changes on lipid profile, oxLDL, fat mass and TNFalpha expression were reported of the comparison between basal and final time points. The statistical analysis was performed with SPSS software.

The investigators assessed 114 women with the eligibility criteria: obese women older than 18y, in good health, as determined by a medical history questionnaire, and normal results of clinical laboratory tests excluding lipids. Exclusion criteria was: history of cardiovascular, hepatic, gastrointestinal, or renal disease; no alcoholism, no smoking, no exogenous hormone use or other medication; no supplemental vitamin or infusion drinking (tea, coffee); or treatment for weight loss 3 months before the start of the study. A total of 64 female, Mexican obese patients were included. We conducted the trial between April 2007 and December 2007 in Guadalajara, Jalisco, Mexico. All of the studies were conducted at Departamento de Biología Molecular en Medicina, Hospital Civil "Fray Antonio Alcalde". This study was approved by the Ethical Committee for Human Research, Universidad de Guadalajara (registration number 028/10). The procedures were in accordance with this institution's guidelines and written consent was obtained from each study subject.

The subjects were undergoing nutritional intervention was reduced by 500 kcal per day of habitual caloric intake. The proportion of daily intake of macronutrient in the moderate-fat diet was: 30% fat (saturated fat <7%, monounsaturated 10-15% and polyunsaturated 10%, respectively to total calories), 15% of protein, and 55% of carbohydrates. The dietary cholesterol was less than 200 mg/day, fiber intake was increased to 25 grams per day (50% soluble fiber).

The patients drank secha green tea. Subjects of the INT group were instructed on how to prepare the green tea infusion. Each cup was prepared using 3g of dried green tea in 300ml of hot water (temperature 80°C)for 4 min. It was drunk fresh and without sugar. The treatment consisted of 2 cup/day of green tea, one in the morning and one at night. The amount of epigallocathechin-3-gallate was 498mg/day.

Change in low density cholesterol, change in high density cholesterol, change in triglycerides, change in oxLDL and change in fat mass were assessed at the beginning and at each month during 3 months of intervention. Change in TNF alpha levels was assessed at the beginning and after 3 months. The final changes of all the measures were reported of the comparation between basal and after 3 months.

Inclusion Criteria: obese women older than 18 years, in good health, as determined by a medical history questionnaire, and normal results of clinical laboratory tests excluding lipids Exclusion Criteria: history of cardiovascular, hepatic, gastrointestinal, or renal disease; no alcoholism, no smoking, no exogenous hormone use or other medication; no supplemental vitamin or infusion drinking (tea, coffee); or treatment for weight loss 3 months before the start of the study