Effectiveness of Green Tea in a Randomized Human Cohort: Relevance to Diabetes and Its Complications

Abstract

Epidemiological studies have argued that green tea could mitigate diabetes and its complications. This study investigated the phytophenolic profile of Mauritian green tea and its antioxidant propensity. The effect of green tea on the risk factors: waist-hip ratio, glucose level, arterial pressure, antioxidant status, and alanine aminotransferase (ALT) in prediabetics was assessed. The experimental group consumed 3 cups of green tea daily for 14 weeks followed by a 2-week washout period. The control group followed a water regimen. Green tea contained high level of phenolics related to its antioxidant power. Green tea suppressed waist-hip ratio of women from a significant increase and suppressed mean arterial pressure of men and women from a significant decrease after week 14. It reduced ALT level in women by 13.0% (P < 0.1) while increasing the antioxidant potential of men and women sera by 2.7% (P < 0.1) and 5.1% (P < 0.1). The study timescale may have been too short to enable demonstration of effects on fasting plasma glucose and HbA1c outcomes. Green tea regimen could form part of a healthy lifestyle that might ameliorate features of metabolic syndrome and subsequent risks for diabetes and its complications. This trial is registered with ClinicalTrials.gov NCT01248143.

Nutritional intervention and impact of polyphenol on glycohemoglobin (HbA1c) in non-diabetic and type 2 diabetic subjects: Systematic review and meta-analysis

“…And so forth, relate the change in HbA1c concentration to an increase in polyphenols intake. In this case, only 7 (Balzer et al, 2008;Curtis et al, 2012;Fenercioglu et al, 2010;Kudolo et al, 2005;Pan et al, 2007;Toolsee et al, 2013;Vinson et al, 2012) of the trial included in the meta-analysis included polyphenol metabolites analysis or antioxidant capacity assay.…”

Effect of green tea supplementation on blood pressure among overweight and obese adults

“…four with less than or equal to 3-day duration [56][57][58][59], and two with 7-day intervention [60,61]). One study [62] reported data only on mean arterial pressure, rather than SBP and DBP, and therefore was excluded. Two studies [63,64] using overweight and obese participants were also excluded because no data on BP were reported.…”

Liver-related safety assessment of green tea extracts in humans: a systematic review of randomized controlled trials

“…19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52 Among the 34 studies, 28 were studies with the primary objective of efficacy assessment and six were studies for safety assessment. The subjects were healthy (10 studies), obese (seven studies), cancer patients (five studies) or other (12 studies).…”