Effect of Epigallocatechin Gallate Supplementation on Inflammation, Iron Status, and Metabolomic Profiles in Women With Obesity: A Pilot Randomized Controlled Trial

Abstract

Obesity in women of reproductive age is often associated with low-grade inflammation and functional iron deficiency. Epigallocatechin gallate (EGCG), a major green tea catechin, has antioxidant, anti-inflammatory, and metabolic-regulating properties but may also interfere with iron absorption. This randomized, double-blind, placebo-controlled pilot study evaluated the effects of EGCG on lipid profile, inflammation, iron status, and plasma metabolomics in women with obesity. Seventeen participants (BMI ≥30 kg/m²; age 20–44 years) received 400 mg/day EGCG (green tea extract: 98% polyphenols, 60% catechins, ∼50% EGCG) or placebo for eight weeks. Outcomes included serum lipids, inflammatory markers (CRP, IL-6, TNF-α, IL-10), iron indices (ferritin, hepcidin, serum iron, transferrin saturation), glucose, and metabolomics. No between-group difference remained significant after correction for multiple comparisons. Total cholesterol (β = −10.9 mg/dL; p  = 0.16) and LDL-C (β = −9.7 mg/dL; p  = 0.16) showed decreases, and IL-6 the largest, though nonsignificant, reduction (p  = 0.09); other cytokines and glucose were unchanged. Metabolomics identified 29 nominally differential metabolites enriched in lipid metabolism, plasmalogen biosynthesis, and mitochondrial β-oxidation, none surviving FDR correction. Iron status was stable. These findings suggest metabolic effects of EGCG and support short-term safety at 400 mg/day. Larger, longer trials with targeted metabolomics are warranted.