Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) are enzymes primarily found within liver cells. Elevated levels in a blood test signal that the liver is experiencing stress, inflammation, or cellular damage. These enzymes are naturally present to assist with metabolism, but higher concentrations in the bloodstream indicate injured liver cells have leaked their contents. Adopting specific lifestyle and dietary adjustments promotes liver healing and lowers these enzyme levels back toward a healthy range.
What Elevated AST and ALT Levels Indicate
Elevated AST and ALT levels are direct evidence of hepatocyte injury, or damage to liver cells. Alanine aminotransferase (ALT) is found mostly in the liver, making it a more specific indicator of liver health than AST. Aspartate aminotransferase (AST) is also found in other organs, including the heart, skeletal muscles, and kidneys.
Therefore, an elevated AST level alone might sometimes point to a non-liver issue, such as intense exercise or muscle trauma.
When both enzymes are significantly elevated, the most frequent cause is Non-Alcoholic Fatty Liver Disease (NAFLD), where excess fat accumulates in the liver cells, often related to obesity and metabolic syndrome. Other common causes include viral hepatitis (B or C), excessive alcohol consumption, and certain medications toxic to the liver. The ratio between AST and ALT can offer further clues; for example, an AST/ALT ratio greater than 2:1 is often associated with alcohol-induced liver damage.
Nutritional Strategies for Reduction
Modifying dietary intake is an effective natural method for reducing elevated liver enzymes, especially when the cause is fatty liver disease. A primary focus involves reducing the consumption of simple sugars, particularly fructose and sucrose, which the liver rapidly converts into fat. Eliminating sugar-sweetened beverages, including soft drinks and fruit juices, and limiting processed foods high in added sugars reduces the metabolic burden on the liver.
Limiting unhealthy fats is similarly important, meaning a reduction in saturated and trans fats found in fried and processed snack foods. Instead, the diet should favor healthy sources of fat, such as monounsaturated fats from olive oil and omega-3 fatty acids found in fatty fish like salmon and mackerel. Omega-3s possess anti-inflammatory properties that help decrease liver inflammation and fat content.
Increasing consumption of fiber-rich foods like whole grains, legumes, and cruciferous vegetables supports liver health by aiding in weight management and detoxification. Foods rich in antioxidants, such as berries and leafy greens, help protect liver cells from oxidative stress. Regular consumption of black coffee has also been associated with improved liver function and lower ALT and AST levels.
Essential Lifestyle Changes
Achieving and maintaining a healthy body weight is the most impactful lifestyle change for lowering elevated liver enzymes, particularly for individuals with NAFLD. Research indicates that a sustained weight loss of just 5% to 10% of total body weight can significantly reduce liver fat and inflammation, contributing directly to the normalization of enzyme levels. This reduction in body fat lessens the influx of fatty acids to the liver, thereby reducing cellular stress.
Regular physical activity complements dietary changes by improving insulin sensitivity and helping to mobilize liver fat stores. Incorporating a combination of aerobic exercise, such as brisk walking or running, and resistance training supports liver health. Aiming for at least 30 minutes of moderate-intensity activity most days of the week is a practical starting goal.
Minimizing exposure to environmental and chemical toxins is also a protective measure. Since the liver clears all toxins, reducing exposure to industrial chemicals, pesticides, and excessive use of certain over-the-counter pain relievers helps decrease its workload. Managing chronic stress and ensuring adequate, restorative sleep supports overall metabolic function, which indirectly aids the liver’s recovery.
Targeted Supplements and Professional Guidance
Several natural compounds may assist in lowering enzyme levels, but they should always be discussed with a healthcare provider first. Milk thistle, specifically its active compound silymarin, is a studied supplement frequently used for its antioxidant and anti-inflammatory properties. Vitamin E, an antioxidant, has shown promise in non-diabetic adults with NAFLD, typically dosed between 400 to 800 IU daily. However, high-dose use requires careful medical monitoring due to potential risks.
N-Acetyl Cysteine (NAC) acts as a precursor to glutathione, a powerful antioxidant that supports the liver’s detoxification pathways. Probiotics may also improve the gut-liver axis, which can reduce inflammation affecting the liver. Supplement use must be approached cautiously, as certain herbal remedies and high-dose vitamins can sometimes cause or worsen liver injury or interact dangerously with existing medications.
Elevated AST and ALT levels require a medical diagnosis to determine the underlying cause, as treatment varies significantly depending on whether the issue is fatty liver, viral hepatitis, or a medication side effect. Consulting a doctor allows for comprehensive testing and follow-up to monitor enzyme levels and ensure natural strategies effectively address the root problem. Self-treating high liver enzymes without professional oversight risks delaying the diagnosis of a serious condition.