Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) are enzymes involved in amino acid metabolism. While primarily concentrated in liver cells, AST is also present in tissues like muscle and the heart. When liver cells become inflamed or damaged, they release these enzymes into the bloodstream, resulting in elevated levels detectable on a blood test. Elevated AST and ALT are not diseases themselves but common signs of liver stress or injury. This article focuses on non-medical steps to support liver health and potentially reduce these enzyme levels.
Understanding Why Levels Become Elevated
High AST and ALT levels signal liver cell damage, often due to inflammation or fat accumulation within the organ. The most frequent cause of chronic elevation is Non-Alcoholic Fatty Liver Disease (NAFLD), which is strongly linked to obesity, type 2 diabetes, and metabolic syndrome. In NAFLD, excess fat builds up in the liver, leading to inflammation and cellular damage. This condition is now often referred to as Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD).
Excessive alcohol consumption is another major factor, as the liver metabolizes alcohol and can be overwhelmed by heavy drinking, leading to tissue damage. The pattern of enzyme elevation can sometimes hint at the cause; for instance, in non-alcoholic causes like NAFLD, ALT is typically higher than AST, while the reverse is often true in advanced alcohol-associated liver disease. Certain medications, including prescription drugs like statins and common over-the-counter pain relievers, particularly high doses of acetaminophen, can also cause enzyme levels to rise. Acute muscle injury or strenuous exercise can also transiently elevate AST because of its presence in muscle tissue.
Dietary Changes to Support Liver Function
A primary strategy for lowering elevated liver enzymes involves making changes to dietary intake, focusing on reducing substances that promote fat accumulation in the liver. A significant part of this approach is the strict reduction or total elimination of alcohol, as its metabolism directly stresses liver cells and is a major cause of enzyme elevation. For those with diagnosed liver disease, complete abstinence from alcohol is often the recommendation.
Reducing the intake of refined carbohydrates and saturated fats is necessary, as these are primary drivers of NAFLD. Foods containing high-fructose corn syrup, sugary drinks, and processed snacks should be limited, since high fructose intake contributes to the accumulation of liver fat. Instead, the diet should prioritize increasing fiber intake through whole grains, vegetables, and legumes, which helps slow carbohydrate absorption.
Incorporating foods rich in antioxidants can help alleviate liver damage and reduce inflammation caused by oxidative stress. Berries, leafy greens, and coffee have been noted for their beneficial effects, with regular coffee consumption potentially helping to reduce both ALT and AST levels. Additionally, ensuring adequate intake of folate, found in foods like spinach and beans, may have a positive effect on ALT levels.
Lifestyle Modifications and Medication Review
Beyond dietary adjustments, lifestyle changes are effective in supporting liver health and reducing enzyme levels. Weight management is particularly effective, especially since excess body weight, particularly abdominal fat, is a major risk factor for liver stress. Even a modest weight reduction of 5% to 10% of total body weight can significantly reduce liver fat and lead to sustained improvement in enzyme levels.
Regular physical activity improves the body’s metabolic profile, which is important for reducing liver fat. Exercise enhances insulin sensitivity, allowing the body to process sugars more effectively and reducing the burden on the liver. Aerobic activity, such as brisk walking, performed for 150 to 300 minutes per week, can reduce liver fat independent of significant weight loss. Incorporating resistance training at least twice a week further supports metabolic control.
It is important to review all current medications and supplements with a healthcare provider, as many common products can be hepatotoxic, meaning they can cause liver injury. This review includes both prescription drugs and over-the-counter supplements that stress the liver. Adjusting the dosage or switching medications under medical supervision may be necessary to remove a pharmaceutical cause of enzyme elevation.
When to Seek Professional Medical Guidance
While lifestyle changes are supportive, they are not a substitute for medical diagnosis and monitoring. If blood tests reveal elevated AST or ALT levels, a healthcare provider should be consulted to determine the underlying cause. High levels can be a sign of conditions that require specific medical treatment, such as chronic viral hepatitis or advanced fibrosis.
Immediate medical attention is necessary if enzyme levels are extremely high (more than five times the upper limit of normal) or if the individual experiences symptoms of advanced liver issues. These symptoms include jaundice, severe fatigue, unexplained nausea, or pain in the upper right side of the abdomen. If lifestyle changes have been consistently followed for several months and repeat blood work shows no improvement, further medical evaluation is warranted.