Liver Health

High ALT and AST: What Your Liver Enzymes Are Telling You

May 27, 2026 16 min read Dr. Mariia Tanasyshyn, ND
A doctor presents a transparent liver illustration in a clinical setting.

Your doctor ordered routine bloodwork. Everything looks fine until you see it: ALT 78 U/L. AST 62 U/L. Flagged in red. "Mildly elevated liver enzymes." Now what?

Elevated ALT and AST are among the most common abnormalities found on routine blood panels, yet they are frequently dismissed with a "let's repeat it in three months" approach. In integrative and naturopathic medicine, elevated liver enzymes are never just a number. They are a signal that something is stressing the liver, and that signal is worth investigating and addressing now.

This article covers what ALT and AST actually are, what levels are truly concerning, the most common causes, and a comprehensive naturopathic approach to restoring liver health.

Key Takeaway

Elevated ALT and AST are a warning sign, not a diagnosis. They indicate liver cell damage or stress, and the goal is to identify the root cause and support liver recovery before the condition progresses. Most causes are reversible with the right approach.

What Are ALT and AST?

ALT (Alanine Aminotransferase) and AST (Aspartate Aminotransferase) are enzymes primarily found inside liver cells (hepatocytes). Under normal circumstances, very small amounts circulate in the bloodstream. When liver cells are damaged or inflamed, they release these enzymes into the blood, causing levels to rise.

ALT

Alanine Aminotransferase

More liver-specific than AST. ALT is found predominantly in the liver, making it the more sensitive marker for liver cell damage. Elevated ALT almost always points to a liver issue.

Normal range (conventional): 7-56 U/L (men), 7-45 U/L (women)

Optimal (functional): below 25-30 U/L

AST

Aspartate Aminotransferase

Found in the liver, heart, skeletal muscle, kidneys, and red blood cells. Less liver-specific than ALT but elevated AST alongside elevated ALT strongly points to liver disease.

Normal range (conventional): 10-40 U/L (men), 9-32 U/L (women)

Optimal (functional): below 25 U/L

The AST/ALT Ratio: A Useful Clinical Tool

The AST/ALT ratio can help differentiate causes. A ratio below 1 (ALT higher than AST) suggests non-alcoholic fatty liver disease (NAFLD) or viral hepatitis. A ratio above 2 strongly suggests alcoholic liver disease. A ratio of 1-2 may indicate cirrhosis or non-alcoholic steatohepatitis (NASH).

How Elevated Is Too Elevated?

Conventional lab ranges are based on population averages, not optimal health. In functional medicine, we often use tighter reference ranges. Even a "mildly elevated" result within the conventional range can be clinically significant if it represents a change from your baseline or occurs alongside other metabolic findings.

Level Times Upper Limit of Normal Clinical Significance
Optimal Below 0.5x ULN Ideal liver function
Mild elevation 1-3x ULN Warrants investigation; most causes reversible
Moderate elevation 3-10x ULN Significant liver stress; further workup essential
Marked elevation 10-50x ULN Acute liver injury; urgent medical evaluation
Severe elevation Above 50x ULN Acute liver failure; emergency care required

Common Causes of Elevated ALT and AST

Identifying the root cause is the most important step. The following are the most frequently seen causes in clinical practice, from the most common to the less obvious.

Non-Alcoholic Fatty Liver Disease (NAFLD)

Most Common Cause

The leading cause of elevated liver enzymes in developed countries. Fat accumulates in liver cells, causing inflammation and cell damage. Strongly associated with insulin resistance, obesity, metabolic syndrome, and high-fructose diets. ALT is typically higher than AST (ratio below 1).

Alcoholic Liver Disease

Even moderate alcohol intake can elevate liver enzymes. Alcohol is directly hepatotoxic and depletes key liver nutrients including folate, B6, zinc, and glutathione. AST is typically higher than ALT (ratio above 2) in alcoholic liver disease.

Medications and Supplements

Frequently Overlooked

Drug-induced liver injury (DILI) is one of the most commonly missed causes. Medications that frequently elevate liver enzymes include:

  • Statins (cholesterol-lowering drugs)
  • Acetaminophen (even at therapeutic doses with chronic use)
  • NSAIDs (ibuprofen, naproxen)
  • Antibiotics (amoxicillin-clavulanate, fluoroquinolones)
  • Antifungals (fluconazole, ketoconazole)
  • High-dose niacin, certain herbal supplements

Viral Hepatitis (A, B, C, D, E)

Hepatitis B and C are chronic viral infections that can persist silently for years while causing ongoing liver cell damage. Hepatitis C is notoriously asymptomatic. Any unexplained elevation of liver enzymes should include hepatitis B and C serology in the workup.

Autoimmune Hepatitis

The immune system mistakenly attacks liver cells. More common in women. Can present with fluctuating liver enzyme levels and may be missed for years. Anti-smooth muscle antibody (ASMA) and ANA testing help in diagnosis.

Thyroid Dysfunction

Commonly Missed

Both hypothyroidism and hyperthyroidism can elevate liver enzymes. Hypothyroidism reduces bile flow and fat metabolism, promoting fatty liver. Hyperthyroidism increases hepatic oxygen demand and can cause direct liver cell stress. Always check TSH, free T3, and free T4 alongside liver enzymes.

Intense Exercise or Muscle Damage

Because AST is also found in muscle tissue, intense or unaccustomed exercise (especially eccentric exercise) can significantly raise AST levels. This is a non-hepatic cause that is often missed. If AST is elevated but ALT is normal, consider checking CK (creatine kinase) to rule out muscle-derived elevation.

Other Causes to Consider

  • Celiac disease (gluten triggers liver inflammation in some patients)
  • Hemochromatosis (iron overload depositing in the liver)
  • Wilson's disease (copper accumulation, especially in younger patients)
  • Alpha-1 antitrypsin deficiency
  • Congestive heart failure (reduced hepatic blood flow)
  • SIBO and gut dysbiosis (the gut-liver axis)

What Tests Should You Ask For?

ALT and AST are a starting point, not a complete picture. A thorough liver workup includes additional tests to identify the cause and assess the degree of liver involvement.

Liver Panel

  • ALT and AST
  • GGT (gamma-glutamyl transferase)
  • ALP (alkaline phosphatase)
  • Total and direct bilirubin
  • Albumin and total protein
  • INR/PT (coagulation)

Cause Workup

  • Hepatitis B surface antigen and antibody
  • Hepatitis C antibody
  • TSH, free T3, free T4
  • Fasting glucose, insulin, HbA1c
  • Ferritin and iron panel
  • Lipid panel (triglycerides)

Autoimmune Screen

  • ANA (antinuclear antibody)
  • Anti-smooth muscle antibody (ASMA)
  • Anti-mitochondrial antibody (AMA)
  • tTG-IgA and IgG (celiac)

Functional/Advanced

  • CK (rule out muscle-derived AST)
  • Liver ultrasound (assess steatosis)
  • FibroScan (liver stiffness/fibrosis)
  • Organic acids and gut microbiome testing

Naturopathic Strategies to Lower ALT and AST

The naturopathic approach prioritizes addressing the root cause while simultaneously supporting liver regeneration and reducing oxidative stress. The following strategies are evidence-based and used in clinical practice.

1. Dietary Foundations

The single most impactful intervention for most patients with elevated liver enzymes, especially NAFLD-related, is dietary change.

EMPHASIZE

  • Cruciferous vegetables (broccoli, cauliflower, Brussels sprouts)
  • Bitter greens (dandelion, arugula, radicchio)
  • Berries and antioxidant-rich foods
  • Olive oil and omega-3 rich fish
  • Garlic and onions (sulfur compounds)
  • Coffee (2-3 cups/day shown to reduce liver enzyme levels)

ELIMINATE OR REDUCE

  • Alcohol (completely if liver enzymes are elevated)
  • Added sugars and high-fructose corn syrup
  • Ultra-processed foods
  • Trans fats and industrial seed oils
  • Refined carbohydrates and white flour products

2. Milk Thistle (Silymarin)

The most extensively studied hepatoprotective herb. The active compound silymarin has been shown in multiple clinical trials to significantly reduce ALT and AST levels. It works by stabilizing hepatocyte cell membranes, increasing glutathione synthesis, stimulating protein synthesis for liver regeneration, and reducing hepatic inflammation. Typical therapeutic dose: 420-600 mg of standardized silymarin extract daily.

3. N-Acetyl Cysteine (NAC)

A precursor to glutathione, the liver's primary antioxidant and detoxification molecule. NAC replenishes glutathione stores depleted by chronic liver stress, alcohol, acetaminophen, and environmental toxins. Research supports its use for NAFLD and drug-induced liver injury. Typical dose: 600-1200 mg daily.

4. Berberine

A botanical compound with strong evidence for NAFLD and insulin resistance. Multiple RCTs show berberine reduces ALT, AST, triglycerides, and improves hepatic steatosis. Works via AMPK activation, improving mitochondrial function and reducing hepatic lipogenesis. Typical dose: 500 mg two to three times daily with meals.

5. Omega-3 Fatty Acids

EPA and DHA reduce hepatic fat accumulation by downregulating lipogenic genes and upregulating fat oxidation pathways. Meta-analyses support omega-3 supplementation for reducing ALT, AST, and liver steatosis in NAFLD. Therapeutic dose: 2-4 g of combined EPA/DHA daily from high-quality fish oil.

6. Vitamin E

Oxidative stress is a key driver of liver cell damage. The PIVENS trial demonstrated that Vitamin E (800 IU/day as alpha-tocopherol) significantly reduced ALT, AST, and liver histology scores in non-diabetic NASH patients. Best used under supervision given higher-dose considerations.

7. Exercise and Weight Management

Even a 5-10% reduction in body weight has been shown to significantly reduce ALT and AST in overweight patients with NAFLD. Aerobic exercise independently reduces hepatic fat even without weight loss. Aim for 150-300 minutes of moderate aerobic activity per week, combined with resistance training.

8. Gut-Liver Axis Support

The liver is directly connected to the gut via the portal circulation. Bacterial endotoxins (LPS) from a dysbiotic gut continuously challenge the liver, driving inflammation. Addressing SIBO, intestinal permeability, and gut dysbiosis is critical for any patient with persistent liver enzyme elevation. This includes targeted probiotics, prebiotics, and gut barrier repair nutrients.

Important: These naturopathic strategies are most appropriate for mild to moderate enzyme elevations (1-3x ULN) when serious underlying disease has been ruled out or is being treated concurrently. Always work with a healthcare provider before starting a supplement regimen.

Frequently Asked Questions

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