From the Guidelines
Excessive dietary protein intake is unlikely to cause hepatic dysfunction in healthy individuals, but those with pre-existing liver disease should consume protein within the recommended range of 1.2-1.5 g/kg/day to minimize protein loss and prevent worsening of liver function. This recommendation is based on the most recent and highest quality study available, which suggests that patients with cirrhosis have increased protein needs and can safely utilize up to 1.8 g/kg/day of protein without worsening hepatic encephalopathy 1.
Key points to consider:
- Protein intake of 1.2-1.5 g/kg/day is recommended for adults with cirrhosis to prevent loss of muscle mass and reverse muscle loss in those who are sarcopenic 1.
- The type of protein consumed may have an impact on liver function, with vegetable and casein-based protein diets potentially being more beneficial than meat protein diets in reducing hepatic encephalopathy 1.
- Patients with liver disease should be encouraged to consume protein from a diverse range of sources, including vegetable and dairy products, and to avoid excessive protein restriction 1.
- Energy supply needs to balance total energy expenditure, and patients with cirrhosis may require 35 kcal/kg/day or more to prevent accelerated starvation and proteolysis 1.
In terms of protein intake and liver health, it is essential to consider the individual's overall health status and liver function. For healthy individuals, moderate protein intake is unlikely to cause liver problems, but those with pre-existing liver disease should consult with a healthcare provider to determine the appropriate protein levels for their specific health situation. Additionally, patients with liver disease should be aware of the potential risks of excessive protein restriction and the importance of consuming a balanced diet that includes a variety of protein sources 1.
From the Research
Hepatic Dysfunction and Dietary Protein Intake
- Excessive dietary protein intake is not directly linked to hepatic dysfunction in the provided studies 2, 3, 4, 5, 6.
- However, high protein intake has been shown to be well tolerated and associated with an improvement of liver function and nutritional status in patients with liver cirrhosis 2.
- Protein restriction is only necessary in rare patients with refractory encephalopathy, and recommendations for general protein restriction are considered obsolete 2, 4.
- The quality and quantity of protein intake are important, and excessive intake (>2 g per kg BW per day for adults) may result in digestive, renal, and vascular abnormalities 6.
Protein Intake and Liver Disease
- Protein deficiency is often associated with liver disease, and the principal cause of protein deficiency is decreased dietary intake 5.
- The protein requirements in most patients with compensated chronic liver disease are not different from normal, but increase during episodes of hepatocellular deterioration 5.
- An increased demand for protein after liver injury drains nitrogen from other organs such as muscle, and aromatic amino acids released from muscle accumulate in the circulation of patients with chronic liver disease 5.
Dietary Protein Intake and Mortality
- Higher intake of total and dairy protein is associated with a lower risk of cirrhosis-related mortality, while higher intake of animal protein is associated with an increased risk of mortality in patients with liver cirrhosis 3.
- Vegetable protein intake is inversely but not significantly associated with mortality risk in patients with liver cirrhosis 3.