Table 3.
The effects of tea on diabetes mellitus and its complications based on clinical trials.
| Tea Types | Diseases Types | Study Types | Participants | Dose and Duration | Results | Ref. |
|---|---|---|---|---|---|---|
| Green tea | Diabetes mellitus | RCT | Patients with T2DM (N = 63) | 0, 2, 4 cups per day | ↓ Body weight, body mass index, waist circumference and systolic blood pressure. | [155] |
| Green tea | Diabetes mellitus and diabetic nephropathy | RCT | Patients with diabetes mellitus (N = 60) | 2 capsules containing 1120 mg polyphenols per day for 20 weeks. | No significant effect on diabetes mellitus and diabetic nephropathy. | [158] |
| Green tea | T2DM and diabetic cardiomyopathy | RCT | Subjects with T2DM and lipid abnormalities (N = 92) | 500 mg per day | ↓ Triglyceride ↑ High density lipoprotein cholesterol ↑ Glucagon-like peptide 1 in the therapeutic arm |
[156] |
| Green tea | Diabetic osteoporosis | RCT | Patients with diabetes mellitus (N = 35) | 1120 mg polyphenols per day | ↑ Bone mineral content ↓ PTH |
[153] |
| Green tea | Bone turnover induced by diabetes mellitus | RCT | Patients with T2DM (N = 72) | 500 mg per day | ↓ Fasting serum osteocalcin ↓ FBG ↓ HbA1C |
[154] |
| Black tea | T2DM and diabetic cardiovascular | N/A | Patients with T2DM (N = 46) | 150, 300, 450, and 600 mL black tea during the weeks 1, 2, 3 and 4. | ↓ Serum malondialdehyde ↓ Serum C-reactive protein ↑ Glutathione |
[58] |
| Oolong tea | T2DM | N/A | Patients with T2DM | 1500 mL per day | ↓ Concentrations of plasma glucose and fructosamine | [73] |
| Green and black tea | T2DM | RCT | White persons (N = 49) | 0, 375, or 750 mg per day for 3 months | No significant effect on T2DM. | [159] |
N/A, not available; RCT, randomized, controlled clinical trial; FBG, Fasting blood glucose; T2DM, type 2 diabetes mellitus; PTH, parathyroid hormone; HbA1C, hemoglobin A1c.