Antioxidant potential of mate tea (Ilex paraguariensis) in type 2 diabetic mellitus and pre-diabetic individuals

• Type 2 diabetic mellitus and pre-diabetic subjects ingested 1 L of mate for 60 days.
• Mate tea intake enhanced antioxidant defense in diabetic and pre-diabetic subjects.
• Lipid peroxidation was decreased in diabetic patients after mate tea ingestion.

The effect of long-term mate tea (Ilex paraguariensis) consumption on the oxidative stress biomarkers of type 2 diabetic mellitus and pre-diabetic individuals was investigated. A 60-day intervention pilot study where 11 T2DM and 11 pre-diabetic volunteers ingested 1 L/day of mate tea was carried out. Ferric reducing antioxidant power (FRAP), erythrocyte reduced glutathione (GSH), serum lipid hydroperoxides (LOOH) using ferrous oxidation-xylenol orange (FOX2), advanced glycation end-products (AGEs), and glycaemic and lipid profiles were assessed at baseline and after 20, 40, and 60 days of intervention. Mate tea consumption promoted a significant increase of GSH concentration and a decrease of LOOH levels in T2DM and pre-diabetic subjects. In addition, GSH concentration was inversely correlated with LOOH in T2DM and pre-diabetic individuals and with AGEs in T2DM subjects. No correlations between glycaemic and lipid profiles with oxidative stress biomarkers were found. Thus, ingestion of mate tea attenuated oxidative stress in T2DM and pre-diabetic subjects, which may prevent diabetes complications.