Green tea, the lightly processed leaf of the tea plant taken as a brewed beverage, powder or concentrated extract supplements, is used as a health and longevity habit. It produces small drops in cholesterol and blood pressure, mainly with extracts, and Asian population studies tie regular drinking to longer life. Brewed tea offers modest, low-risk potential benefits; high-dose extracts, especially taken on an empty stomach, can injure the liver. (Full Review)
| Marker | Target | Why |
|---|---|---|
| ALT | 10–25 U/L | Detects extract liver injury |
| AST | 10–25 U/L | Confirms liver pattern |
| GGT | 10–25 U/L | Sensitive liver marker |
| Ferritin | 50–150 ng/mL | Iron-absorption effect |
| Hemoglobin | 13.5–15.5 g/dL (men); 12.5–14.5 g/dL (women) | Detects anemia |
| LDL cholesterol | Below 100 mg/dL | Tracks lipid benefit |
| ApoB | Below 80 mg/dL | Atherogenic particle count |
| Blood pressure | Below 120/80 mmHg | Tracks vascular benefit |
| Fasting glucose | 75–90 mg/dL | Glycemic effect |
| HbA1c | Below 5.4% | Longer-term glycemia |
| hs-CRP | Below 1.0 mg/L | Inflammation trend |
| TSH | 1.0–2.5 mIU/L | Thyroid effect at high doses |
| Serum folate | Above 15 ng/mL | Folate absorption |
| HLA-B*35:01 | Not carried | Extract liver-injury risk |
Cadence: Baseline before extracts or heavy daily intake; for extract users, liver enzymes at 1, 3 and 6 months, then every 6–12 months; lipids, ApoB, blood pressure and ferritin at 3 months, then every 6–12 months. Brewed-tea drinkers without risk factors follow routine annual labs.