Where your DNA places you among other people, and the studies behind it.
Not tailored to your result, and not medical advice
Aim for Sustained Weight Loss: Most mildly raised ALT in adults traces back to fat accumulating inside liver cells, and weight reduction is the lifestyle change with the strongest evidence behind it. In intervention trials, roughly 5% body weight loss was enough to reduce liver fat, 7-10% was associated with improvement in liver inflammation, and 10% or more with improvement in fibrosis. Weight reduction through calorie restriction, with or without added physical activity, improved liver enzymes alongside those tissue measures. Diabetes Spectrum (PMC)
Keep Alcohol Intake Low: ALT leaks into the blood when liver cells are injured, and alcohol is a direct cause of that injury. In the Rancho Bernardo Study of 2,364 older adults, drinking and excess body weight compounded each other rather than simply adding up: participants who were obese and drank more than three drinks daily had roughly 8.9 times the odds of an elevated ALT compared with normal-weight non-drinkers. Obese participants showed raised odds at lower intakes too, so the threshold that matters is not the same for everyone. Alimentary Pharmacology & Therapeutics (PMC)
Cut Back on Sugary Drinks: Fructose from sweetened drinks is metabolized almost entirely by the liver and drives fat synthesis there, which is why sugary drinks recur in fatty liver research. In an 8-week randomized trial in adolescent boys with fatty liver disease, a diet holding free sugars under 3% of calories cut liver fat from 25% to 17% and lowered ALT from a geometric mean of 103 to 61 U/L, while the usual-diet group barely moved on either measure. Water or unsweetened drinks are the direct swap. JAMA (PubMed)
Check Supplements for Liver Risk: Herbal and dietary supplements account for roughly 16% of drug-induced liver injury cases in US prospective series, with green tea extract the most commonly implicated ingredient and androgenic steroid and multi-ingredient weight-loss products also prominent. Under the 1994 Dietary Supplement Health and Education Act these products reach shelves without FDA pre-market approval, so a clean-looking label is not a safety check. The free NIH LiverTox database catalogs ingredients with documented liver toxicity. A liver enzyme that stays raised while you are taking supplements is worth raising with a clinician. LiverTox, NIH National Institute of Diabetes and Digestive and Kidney Diseases
Exercise Even Without Weight Loss: Physical activity lowers liver fat even when body weight barely changes, which makes it useful on its own rather than only as a weight-loss tool. A 2023 meta-analysis of randomized trials in fatty liver disease found exercise reduced ALT with a pooled standardized mean difference of -0.59, with aerobic and resistance training both showing an effect and programs of 12 weeks or longer doing better than shorter ones. Heterogeneity was high (I-squared 88%), and the same review notes earlier meta-analyses that found no significant ALT change. Journal of Clinical Medicine (PMC)
How much of this is genetic?
Genetics explains 40% of why people differ in this trait. The rest is environment, daily habits and chance.
Heritability estimate: Twin studies place ALT heritability across a wide range, from roughly 22% to 65% (several estimates near 55-60%); a central value of ~40% is used here.
Background and further reading
Alanine aminotransferase (ALT, sometimes written SGPT) is an enzyme found mainly inside liver cells, where it helps convert the amino acid alanine as part of energy metabolism. When liver cells are stressed or damaged, ALT leaks into the bloodstream, so a blood ALT level is one of the most common markers used to gauge liver health. It is a continuous biomarker rather than a disease: most people sit within a broad reference range, and a value simply reflects how much enzyme is circulating at the time of the test. Levels can shift with body weight, alcohol intake, diet, physical activity, certain medications, and recent illness, which is why a single reading is interpreted in context rather than as a diagnosis [1].
Genetic Basis: Twin and family studies show that baseline ALT is partly heritable, with reported estimates spanning a wide range, from roughly 22% to 65%, and several twin studies landing near 55-60% [3]. Even at the higher end, a large share of variation is left to environmental and metabolic factors. Genome-wide association studies of liver enzymes have identified many common variants that nudge ALT up or down [1]. The best-known is PNPLA3 (the I148M variant, rs738409), which affects how the liver handles fat and is strongly linked to fat accumulation and higher ALT [2]. Other genes tied to ALT variation include HSD17B13, GCKR, TRIB1, and the SAMM50/PARVB locus near PNPLA3 on chromosome 22. A polygenic score adds up many such small-effect variants to estimate an inherited baseline tendency; it captures a genetic nudge, not a fixed value.
Associated & Modifiable Factors: Because ALT reflects liver stress, it tracks closely with metabolic and lifestyle factors. The most common driver of mildly elevated ALT in the general population is excess fat in the liver, which is associated with overweight, central adiposity, insulin resistance, and high intake of refined carbohydrate and alcohol. Weight loss, increased physical activity, reduced alcohol, and improved diet are consistently linked to lower ALT. Some medications and supplements can also raise it. A genetic tendency toward higher ALT does not mean a value will be elevated: environment and habits shape the actual reading, and many people with higher-scoring genetics maintain normal levels [1].
The published research behind your score, and the variants it draws on.
9 published scores from 5 studies
The ALT (liver enzyme) score combines 9 polygenic scores drawn from 5 published studies.
These traits are influenced by some of the same genes and variants as this one
Content updated August 2026.
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