(OR12-02-26) Effects of Green Tea Extract Supplementation on Inflammatory Cytokines Among Postmenopausal Women With Overweight or Obesity

Objectives: To evaluate the effect of green tea extract (GTE) supplementation on circulating levels of C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) among postmenopausal women with overweight or obesity and with differing catechol-O-methyltransferase (COMT) genotypes.

Methods: This study is a secondary analysis of a random subset (N=97) from the Minnesota Green Tea Trial, a randomized double-blinded placebo-controlled trial. The intervention was a high-dose GTE supplement (843±44 mg EGCG/ day) or placebo for 1 year. Serum CRP, TNF-α, and IL-6, were measured at 0, 6, and 12 months. Absolute changes in inflammatory cytokines from 0 to 12 months were evaluated using linear mixed-effects models adjusted for age, body mass index (BMI), smoking history, physical activity, and vitamin supplement use.

Results: The participants’ mean (±SD) age was 60 (±5) years, and their BMI was 28.9 (±3.0) kg/m²; 39% of BMI values fell within the obesity range. The changes from 0 to 12 months were not statistically different between the groups for any of the inflammatory cytokines measured. Absolute changes from 0 to 12 months, reported as arithmetic means (95%CI) for the treatment group were: CRP -0.17 (-0.66, 0.31), IL-6 -0.65 (-1.73, 0.43) and TNF-α -0.36 (-1.67, 0.95), compared to the placebo group: CRP 0.31 (-0.52, 1.15),IL-6 0.69 (-0.29, 1.67), and TNF-α 0.34 (-1.00, 1.68). There was no significant treatment effect or interaction (group x time). There was no significant interaction between treatment group and COMT genotype on serum cytokine levels.

Conclusions: Baseline levels of inflammatory cytokines did not indicate low-grade inflammation in this population of overweight and obese postmenopausal women. A high-dose GTE supplement consumed daily for one year did not significantly decrease inflammatory cytokines among postmenopausal women with overweight or obesity. The COMT genotype did not modify the effects of GTE supplementation on inflammatory cytokines.

Funding Sources: The New Jersey Health Foundation; The National Institutes of Health / National Cancer Institute