Avoid These 3 Liver Killers

CONNOR'S HEALTH NOTES

The Panel Named for Function Mostly Measures Injury

Connor Hill · InsightfulWord · September 3, 2026

Nothing here is a reason to start or stop any medication, supplement or treatment. Those decisions belong with a clinician who knows the case. What follows concerns what a standard set of blood tests measures, which is a separate matter and a well-documented one.

The panel is universally called liver function tests, and the name is wrong in a way that has consequences. Most of what it contains does not measure function. It measures injury and it measures obstruction, which are different things with different implications.

The reference sources say so directly. Standard clinical texts describe the term as imprecise and recommend liver chemistries instead, on the grounds that the majority of the components reflect hepatocellular injury or impaired bile flow rather than the organ's capacity to do its work.

The distinction is not academic. A person can have markedly abnormal enzymes with entirely preserved function, and a person with advanced disease can have enzymes that have returned toward normal because there is less tissue left to leak them.

Sorting the panel into its three groups takes a paragraph and changes how every result in it reads. Two of the analytes indicate that cells have been damaged and their contents have escaped into the blood. Two indicate that bile is not flowing as it should. Two — measured by different mechanisms — actually reflect what the organ is still producing.

The popular account runs on a different model entirely, in which the organ becomes progressively blocked by accumulated material and must be cleared. There is no such mechanism. The organ does not fill up, does not store toxins for later, and has no channel that clogs in the sense the metaphor implies.

What it does have is a specific and common problem: fat accumulating within its cells, which is now the most frequent cause of abnormal enzymes in the general population, and which has a name, a staging system and an evidence base.

What follows is how the three groups of the panel divide, why the name misleads, what an elevated transaminase narrows the possibilities to, why the organ does not clog, and the sequence a clinician actually follows.

Injury, Cholestasis and Synthesis

The panel divides cleanly into three categories once the categories are named, and each answers a different question.

The injury markers are the two transaminases. One of them is largely confined to the cytosol of liver cells and is the more specific of the pair. The other is present in heart, skeletal muscle, kidney and red blood cells as well, which is why an isolated elevation of it can come from somewhere other than the liver entirely — vigorous exercise and muscle injury being the common examples.

These enzymes appear in the blood because cells have been damaged and their contents have leaked. The magnitude indicates roughly how much leakage is occurring, and the ratio between the two carries some information about cause.

The cholestasis markers indicate impaired bile flow. Alkaline phosphatase is concentrated in the epithelium lining the bile ducts and rises when flow is obstructed, but it also comes from bone, placenta and intestine, so an elevation alone does not localize. Gamma-glutamyl transferase is the analyte used to confirm that an elevated alkaline phosphatase is hepatobiliary rather than skeletal in origin.

The synthetic markers are the two that measure function. Albumin reflects the organ's protein production, and the prothrombin time expressed as a ratio reflects its production of clotting factors.

Bilirubin sits somewhat apart, reflecting the handling and excretion of a breakdown product, and its two fractions distinguish problems before the liver from problems within or beyond it.

Why the Panel Is Misnamed

The naming problem produces specific misreadings, and each of them is common.

The first misreading is treating a raised enzyme as failing function. It is the opposite: leakage requires living cells to leak from, and a very high transaminase indicates active injury to tissue that is still there.

The second is treating a normal panel as excluding disease. Established cirrhosis frequently presents with normal or near-normal transaminases, because the inflammatory phase has passed. The findings that indicate advanced disease are a falling albumin, a rising bilirubin, a lengthening clotting time and a falling platelet count.

The third is reading the synthetic markers as though they were specific. They are not. Albumin falls in malnutrition, in inflammation of any cause, in protein loss through the kidney or gut. The clotting measure lengthens with vitamin K deficiency and with anticoagulant medication, and distinguishing those from hepatic causes requires knowing what the person takes.

The fourth is comparing values across laboratories. Reference intervals differ between assays and populations, and the upper limit of normal for the transaminases has itself been debated, with proposals to lower it because the historical reference populations included people with undiagnosed fatty liver.

What an Elevated Transaminase Narrows To

An abnormal result is a starting point with a defined differential, and the pattern of abnormality does most of the narrowing.

The first distinction is the pattern: predominantly hepatocellular, predominantly cholestatic, or mixed. Comparing how far each analyte is elevated above its own upper limit sorts a result into one of the three, and the three lead to different investigations.

The second is magnitude. Modest elevations — a few times the upper limit — have a broad differential dominated by common conditions. Very high elevations, in the thousands, have a short list: acute viral infection, drug or toxin injury, an interruption of blood supply, and a small number of others.

The third is duration. A single abnormal result is often transient and resolves on repeat testing, which is why repeating the test is a standard first step rather than a delay.

The most common cause of a persistent modest elevation in the general population is fat accumulation within liver cells associated with metabolic factors — obesity, insulin resistance, elevated triglycerides, raised blood pressure. This condition has been renamed in recent classifications to reflect that metabolic association explicitly.

Alcohol is the other large contributor and produces a characteristic pattern in the ratio between the two transaminases. Medications, including common non-prescription ones taken above recommended doses, are the third large category, and a complete list of what a person takes is part of the workup rather than an afterthought.

The Organ Does Not Clog

The popular model deserves direct treatment, because its intuitive appeal is what carries the claims built on it.

The organ is a chemical processing tissue, not a filter with a mesh. Blood arrives through two supplies, passes through sinusoids lined with cells that take up and transform substances, and leaves. Nothing is strained out and retained.

Its handling of foreign compounds proceeds in two phases: modification of the molecule, then attachment of a water-soluble group so that it can be excreted in bile or urine. The products leave. They are not stockpiled.

Bile ducts can genuinely obstruct — by a stone, a stricture, a tumor, or an inflammatory process — and that obstruction is what the cholestasis markers detect. It is a mechanical event with a specific cause, identifiable on imaging, and it is not what dietary language about clogging describes.

Fat accumulation is real and is the closest the popular model comes to something true. Triglyceride accumulates within the cells themselves, which is visible on imaging and quantifiable, and it can progress to inflammation and scarring in a minority of cases. But it is a metabolic state rather than a blockage, and what reverses it is weight reduction and management of the associated metabolic factors, for which there is trial evidence.

The claim that a single food destroys the organ faster than anything else does not correspond to any recognized mechanism. Injury has identifiable causes, they are enumerated in reference texts, and the enumeration is not a ranking of foods.

The Sequence a Clinician Actually Follows

The workup for an abnormal result is standardized enough to describe, and knowing it makes the process legible.

The first step is usually repetition, since a proportion of abnormalities do not persist. Alongside it comes a history: alcohol intake, all medications including non-prescription and herbal products, risk factors for viral infection, family history, and metabolic factors.

The second step is pattern analysis and a first tier of tests directed by it: viral serology, metabolic markers, and screening for the small number of inherited and autoimmune conditions that are treatable and would otherwise be missed.

The third is imaging, most often ultrasound, which shows fat, biliary dilatation, focal lesions and features suggesting established scarring.

The fourth, where scarring is the question, is non-invasive assessment of stiffness or a calculated fibrosis score, which have substantially reduced the need for biopsy. Biopsy remains available where the non-invasive results are equivocal or the diagnosis is unclear.

What the sequence is designed to do is separate the common and metabolic from the uncommon and specific, because the management differs entirely. That separation cannot be made from a single number, and it cannot be made from a list of foods.

The composite point is that the panel measures three different things under one misleading name, that the pattern and duration of abnormality carry most of the information, and that the organ has no mechanism corresponding to the one the popular account describes.