Researchers tested whether a diet focused on plant-based and dairy proteins could help people with liver cirrhosis maintain their muscle strength and function. They compared 42 patients who either followed this special protein diet or a regular balanced diet for 12 weeks. While both groups showed similar improvements in muscle strength tests, the special protein diet group had better results for a harmful substance called ammonia that builds up in the blood with liver disease. This suggests the protein diet might offer some protection, though more research is needed to confirm these benefits.

The Quick Take

  • What they studied: Whether eating more plant-based and dairy proteins helps people with liver cirrhosis keep their muscles strong and healthy
  • Who participated: 42 adults aged 30-60 years old with liver cirrhosis, split into two equal groups of 21 people each
  • Key finding: The special protein diet group kept harmful blood ammonia levels stable, while the regular diet group’s ammonia levels increased significantly. Both groups showed similar improvements in muscle strength tests, but the protein diet group had better results on blood markers related to muscle breakdown.
  • What it means for you: If you have liver cirrhosis, eating more plant and dairy proteins may help prevent dangerous ammonia buildup in your blood, which is important for brain health. However, this is early research on a small group, so talk with your doctor before making major diet changes.

The Research Details

This was a randomized controlled trial, which is one of the strongest types of medical research. Researchers took 42 patients with liver cirrhosis and randomly divided them into two groups—like flipping a coin to decide who got which diet. One group ate a diet focused on vegetable and dairy proteins (plant-based foods and milk products), while the other group ate a regular balanced diet with all types of protein sources. Both diets had the same number of calories and the same amount of total protein, so the only real difference was the type of protein. The study lasted 12 weeks, and researchers measured muscle strength, walking speed, the ability to stand up from a chair, blood tests, and body measurements at the start and end.

This research approach is important because liver cirrhosis causes a serious problem called sarcopenia, where muscles waste away and become weak. This weakness can lead to brain problems and even death. By randomly assigning people to different diets and measuring specific muscle tests and blood markers, researchers could see if changing the type of protein actually helps. The controlled design means we can be more confident that any differences between groups were caused by the diet, not by other factors.

This study has several strengths: it’s a randomized controlled trial (the gold standard), it measured both muscle function and blood markers, and it was published in a peer-reviewed journal. However, the sample size is small (only 42 people), which means results might not apply to everyone. The study only lasted 12 weeks, so we don’t know if benefits continue longer. The study didn’t measure whether people actually stuck to their diets, which could affect results. Results should be considered preliminary and need confirmation in larger studies.

What the Results Show

After 12 weeks, both groups showed improvements in muscle strength tests including handgrip strength, walking speed, and the ability to stand up from a chair five times. However, these improvements were similar between the two groups—the special protein diet didn’t produce noticeably better muscle function than the regular diet. This was somewhat surprising because researchers expected the special protein diet to help more.

The most important finding was in blood tests. The group eating the special protein diet kept their ammonia levels stable, while the regular diet group’s ammonia levels increased significantly. Ammonia is a toxic substance that builds up when the liver doesn’t work properly, and high levels can damage the brain. The difference between groups was statistically significant, meaning it’s unlikely to be due to chance.

Another blood marker called myostatin, which relates to muscle breakdown, also stayed stable in the special protein diet group but increased in the regular diet group. This suggests the special protein diet may help prevent muscle breakdown at the cellular level, even if muscle strength tests looked similar.

Body measurements including weight, body mass index (BMI), arm circumference, and skin fold thickness did not show significant differences between the two groups. This means both diets maintained body composition similarly. The study also collected information about what people actually ate and their physical activity levels, though the abstract doesn’t detail these results. These measurements help confirm that the diets were truly balanced in calories and total protein, making the ammonia difference more meaningful.

Previous research has shown that sarcopenia in liver disease is a serious problem linked to poor outcomes. Some earlier studies suggested that plant-based proteins might be easier for damaged livers to process compared to animal proteins. This study adds to that evidence by showing that a plant and dairy protein diet may help control ammonia levels. However, the finding that muscle strength didn’t improve more with the special diet is somewhat different from what some researchers expected, suggesting the relationship between protein type and muscle function in liver disease is more complex than previously thought.

The study is small with only 42 participants, which limits how much we can generalize the findings to all people with liver cirrhosis. The 12-week timeframe is relatively short—we don’t know if benefits continue or improve over months or years. The study didn’t measure whether people actually followed their assigned diets consistently, which could affect results. The study didn’t include information about disease severity, medications, or other factors that might influence outcomes. There’s no information about whether the improvements seen were clinically meaningful or just statistically significant. Finally, the study didn’t follow people after the intervention ended to see if benefits lasted.

The Bottom Line

If you have liver cirrhosis, eating more plant-based and dairy proteins while limiting other protein sources may help prevent dangerous ammonia buildup in your blood. This is a moderate-confidence recommendation based on this single study. However, muscle strength improvements were similar between diets, so don’t expect dramatic changes in physical function. Always work with your doctor or a liver specialist and registered dietitian before making significant diet changes, as individual needs vary greatly with liver disease.

This research is most relevant for people with liver cirrhosis who are concerned about muscle loss and brain complications from ammonia buildup. It may also interest caregivers and healthcare providers managing cirrhosis patients. This research is NOT a substitute for medical advice—people with liver disease have complex nutritional needs that require personalized care. Those with kidney disease, severe protein restrictions, or dairy allergies should discuss this diet with their doctor before trying it.

Based on this study, you might expect to see stable ammonia levels within 12 weeks of following the diet. However, improvements in muscle strength and physical function may take longer or may not be dramatic. Most benefits would likely appear within 3-6 months, but individual responses vary. It’s important to monitor blood ammonia levels with your doctor to assess whether the diet is working for you personally.

Want to Apply This Research?

  • Track daily protein intake by source (plant-based vs. dairy vs. other), aiming for a specific target set by your dietitian. Log meals and note the protein source for each meal to ensure you’re meeting the plant and dairy protein goals.
  • Replace one regular protein source per day with either a plant-based option (beans, lentils, tofu, nuts) or a dairy option (yogurt, cheese, milk). Start with one meal and gradually increase as you adjust to the new foods.
  • Weekly tracking of energy levels and physical function using simple tests like timing how long it takes to stand up from a chair five times. Monthly blood work with your doctor to monitor ammonia levels and other liver markers. Keep a food diary to ensure consistency with the diet plan.

This research summary is for educational purposes only and should not replace professional medical advice. Liver cirrhosis is a serious condition requiring specialized medical care. Before making any dietary changes, especially if you have liver disease, consult with your hepatologist (liver specialist) and registered dietitian. This study involved only 42 people over 12 weeks, so results are preliminary. Individual responses to dietary changes vary greatly depending on disease severity, medications, and other health factors. Do not use this information to self-diagnose or self-treat. If you experience symptoms like confusion, yellowing of skin, or severe weakness, seek immediate medical attention.