Alanine aminotransferase (ALT) is an enzyme primarily found within liver cells, where its function is to assist in converting food into energy. When liver cells are damaged, this enzyme leaks into the bloodstream and is detected during a blood test. An elevated ALT level signals that the liver is experiencing stress, inflammation, or injury. This reading is not a diagnosis on its own, but rather an indicator that further investigation and action are needed to protect long-term liver health. This article outlines the common causes of this elevation and provides actionable steps to reduce your ALT levels.
Understanding Why ALT Levels Rise
The most common reason for elevated ALT levels is Non-Alcoholic Fatty Liver Disease (NAFLD). This condition is often tied to metabolic syndrome, which includes factors like obesity, insulin resistance, and high triglyceride levels. Excess calories are stored as fat within the liver cells, causing inflammation and subsequent injury that releases ALT into the blood.
Another significant cause is alcohol consumption, which is directly toxic to liver cells. Even moderate consumption can keep ALT levels elevated, and heavy use causes liver cell death. Chronic viral infections, such as Hepatitis B and Hepatitis C, also cause ongoing inflammation and damage. Finally, some medications, genetic conditions like hemochromatosis (iron overload), and autoimmune conditions can trigger liver stress and an increase in ALT.
Targeted Dietary and Activity Adjustments
Addressing elevated ALT often begins with targeted changes to diet and physical activity, especially when the cause is related to NAFLD. Gradual, sustained weight loss is one of the most effective interventions, as losing even a modest 5% to 10% of body weight can significantly reduce liver fat and inflammation. This reduction in liver fat directly lessens the stress on the hepatocytes, leading to lower enzyme leakage.
Dietary adjustments should focus on reducing processed sugars, including sugar-sweetened beverages, and refined carbohydrates. Shifting to a diet rich in fruits, vegetables, whole grains, and lean proteins helps manage blood sugar and insulin levels, which are closely linked to liver fat accumulation. The Mediterranean diet, emphasizing healthy fats like olive oil and omega-3 fatty acids from fish, is often recommended for its anti-inflammatory benefits.
Regular physical activity is beneficial because it improves insulin sensitivity, making the body more efficient at utilizing glucose and reducing the burden on the liver. A regimen including at least 150 minutes of moderate-intensity aerobic exercise weekly has been shown to reduce liver fat, even independent of significant weight loss. Incorporating resistance training also helps improve metabolic health and overall body composition.
For those who consume alcohol, the need to eliminate or severely restrict intake is paramount, as alcohol is a potent hepatotoxin that directly damages liver tissue. Avoiding alcohol removes a major source of inflammation, allowing the liver cells to regenerate and ALT levels to decline.
The Impact of Medications and Supplements
Many substances taken for other health issues can influence liver enzyme levels, and it is crucial to review all medications and supplements with a healthcare provider. Over-the-counter pain relievers, such as acetaminophen, can cause liver injury and elevated ALT if taken in excessive doses. Certain prescription drugs, including some statins for high cholesterol, nonsteroidal anti-inflammatory drugs (NSAIDs), and certain antibiotics, are also known to potentially raise ALT levels.
If a medication is suspected of causing the elevation, a doctor can assess the necessity of the drug and potentially adjust the dosage or switch to an alternative. Patients should never discontinue a prescribed medication without first consulting their physician. This review ensures that necessary treatments continue while mitigating the risk of drug-induced liver injury.
Regarding dietary and herbal supplements, the evidence for their effectiveness in lowering ALT is often mixed or insufficient. Some popular “liver-support” products have been linked to liver injury. Because these products are not regulated like pharmaceuticals, they can contain unlisted or contaminated ingredients that may pose a risk. Before starting any supplement, discuss it with a healthcare professional to ensure it does not interfere with existing conditions or treatments.
When Professional Medical Guidance is Necessary
While lifestyle changes are the first line of defense, high ALT levels necessitate professional medical oversight to identify the underlying cause and monitor progress. If initial blood tests show persistent elevation, further diagnostic testing is required to rule out more serious or specific liver diseases.
Follow-up testing can include:
- A full liver function panel.
- Imaging tests like ultrasound or elastography to assess liver fat and stiffness.
- Screening for chronic viral infections, such as Hepatitis B and C.
- Testing for less common conditions like autoimmune hepatitis or genetic disorders like Wilson disease.
If ALT levels remain significantly high, or if there is evidence of advanced liver damage, a referral to a specialist—such as a gastroenterologist or hepatologist—is often warranted. These specialists can offer advanced diagnostic procedures, including liver biopsy if necessary, and specific medical treatments tailored to the exact cause of the liver injury. Partnering with a medical professional ensures a comprehensive and safe approach to normalizing ALT levels and protecting long-term liver health.