Gamma GT is a better marker for health than Cholesterol

Gamma GT is a marker for liver health, and historically it has been associated with liver disease due to alchool consumption. However, it is also useful as a more general marker for metabolic health as indicated in this study. It appears that it is a useful as an early marker for disease. Various studies have also shown that it is a useful marker for showing insulin resistance and other metabolic disease.

Gamma-Glutamyltransferase: A Predictive Biomarker of Cellular Antioxidant Inadequacy and Disease Risk

A few of the study highlights:

 GGT is an early predictive marker for atherosclerosis, heart failure, arterial stiffness and plaque, gestational diabetes, and various liver diseases, including viral hepatitis, other infectious diseases, and several life-threatening cancers. We review literature both from the medical sciences and from life insurance industries demonstrating that serum GGT is a superior marker for future disease risk, when compared against multiple other known mortality risk factors.

The prevalence of several other clinical symptoms are correlated with GGT, including hypertension, insulin resistance, artery calcification, and albuminuria, as well as biological markers including lipids, creatine, triglycerides, uric acid, HbA1c, and hs-CRP. In many cases, GGT is a stronger predictor of disease risk than these other symptoms and markers.

What is normal?

Participants having baseline GGT levels above gender medians (16 U/L and 9 U/L, respectively, for men and women) experienced a 1.71-fold risk of heart failure compared to participants having GGT below their gender's baseline median. Importantly, each of these FOS studies showed that testing individuals a single time for GGT provided an early predictive marker for metabolic diseases, including MetS (sometimes referred to as insulin resistance syndrome), CVD, and heart failure, and that that prediction was valid well in advance of participants reaching these hazardous thresholds. This is important because GGT can be lowered by dietary means alone, or by making nominal dietary adjustments combined with minimally intrusive procedures, such as blood donation or therapeutic phlebotomy

Consistent with the dose-response relationship often observed for GGT, the greatest mortality risk categories were for men and women having the highest GGT levels at baseline. Individuals in this high-risk category, representing 15 percent of the entire study group (GGT levels above 56 U/L for men and 36 U/L for women), experienced a 100 percent increased risk of mortality. 

 Studies conducted in Europe have quantified the GGT-related risk of heart disease, cancer incidence, and cancer mortality among both men and women. Among these, Ruttmann et al. reported cardiovascular disease mortalities among a cohort of 163,944 Austrian adults. CVD mortalities occurred in relation to GGT levels ranging from a 17% increased risk for men who had GGT measured in the range of 14–27 U/L, 28% increased risk for those with GGT of 18–24 U/L, 39% increased risk in the GGT range of 42–55 U/L, and a 64% increased mortality risk for those who had GGT levels that measured at 56 U/L or above; each of those risk categories was measured in comparison to those men who had GGT measured below 14 U/L (n = 29,320 or 39% of the male cohort).

Life insurers have used it for years...

Medical science researchers have described the utility of GGT as a predictor of all-cause mortality only during the last fifteen years. However, GGT data has been collected by the life insurance industry for many years. Their principal reason for measuring GGT levels was its ability to mark alcohol abuse or risky drinking behavior in life insurance applicants. When high GGT levels were found in life insurance candidates, premium policy pricing or even application rejection often resulted.

What to do about it

Frequent blood donation or therapeutic phlebotomy is a relatively low-risk strategy for reducing body iron burdens. Curcumin, having a proven capability of chelating poorly liganded iron, has been shown to ameliorate many diseases linked to elevated GGT.