What are ALT, AST & GGT and How to Track Them?

TR: ALT, AST ve GGT Nedir, Nasıl Takip Edilir?

1. What is ALT, AST & GGT (Liver Enzymes Panel)?

ALT (Alanine Aminotransferase) and AST (Aspartate Aminotransferase) are intracellular enzymes that leak into the bloodstream when liver cells (or muscle fibers, in the case of AST) experience stress. GGT (Gamma-Glutamyl Transferase) is a sensitive marker of biliary health, alcohol exposure, and glutathione antioxidant demand.

ALT ve AST, karaciğer hücreleri (AST için aynı zamanda kas lifleri) strese girdiğinde kana karışan hücre içi enzimlerdir. GGT (Gama-Glutamil Transferaz) ise safra yolu sağlığının, oksidatif stresin ve glutatyon antioksidan ihtiyacının en hassas göstergesidir.

2. Why Track ALT, AST & GGT?

• Standard lab cutoffs (ALT up to 45–55 U/L) inadvertently include subclinical MASLD (metabolic fatty liver); true optimal ALT is < 25 U/L in men and < 20 U/L in women.
• GGT > 25–30 U/L is an independent predictor of oxidative stress and cardiometabolic risk even when ALT is normal.
• Intense weightlifting can transiently elevate AST (and mildly ALT) for up to 5 days due to skeletal muscle micro-tears rather than liver injury.

3. How to Track ALT, AST & GGT Accurately

• Rest from heavy eccentric resistance training and avoid alcohol for 48–72 hours before a liver panel draw.
• Track ALT, AST, and GGT alongside Triglycerides, Fasting Insulin, and Ferritin to evaluate metabolic liver fat.
• Review any new prescription medications or herbal supplements if enzymes trend upward.

4. How to Optimize ALT, AST & GGT

• Eliminate fructose-sweetened beverages and reduce alcohol—the two fastest drivers of hepatic de novo lipogenesis (liver fat creation).
• Consume cruciferous vegetables (broccoli sprouts, arugula), coffee (2–3 cups/day), and choline-rich foods (eggs, fish) to support hepatocyte repair.
• Lose 5–7% of body weight if visceral fat is elevated, which rapidly normalizes ALT and GGT.

5. Frequently Asked Questions