Fatty liver is being diagnosed more and more frequently, but there is no drug therapy yet. A healthy lifestyle with exercise and nutrition plays a key role in prevention. A team of gastroenterologists and cardiologists from Paracelsus Medical University Salzburg and the University Hospital Zurich has now investigated the influence of nuts on the formation of a fatty liver.
If we consume more energy than we use, the body stores the excess as fat deposits under the skin, but also in the liver. If there is too much fat in more than five percent of the liver cells, doctors speak of steatosis hepatitis – or less elegantly: a fatty liver. It leads to a restriction of liver function and therefore damages not only the organ but the whole body. This is because fat deposits in the liver and muscles are one of the main causes of type II diabetes and metabolic syndrome. Fatty liver is therefore associated with an increased risk of cardiovascular disease and diseases involving the liver in general.
In the worst case, there is a risk of liver failure
A fatty liver is often caused by a combination of different factors, including alcohol and obesity. Experts distinguish between alcoholic fatty liver, which is caused by excessive alcohol consumption, and non-alcoholic fatty liver, which in rare cases is caused by certain medications, but mainly by a lack of exercise and an unbalanced diet. The tricky thing about liver diseases, including fatty liver, is that they cause no or only minor and vague symptoms for a long time.
However, if left untreated, fatty liver can lead to liver cirrhosis and liver cancer. The only way out is then transplantation. Despite their frequent occurrence, there is still no drug treatment available. The therapy is therefore based on a change in lifestyle and dietary habits. A team of researchers from Paracelsus Medical University Salzburg and the University Hospital Zurich has now conducted a study to investigate how the consumption of nuts affects the development and severity of fatty liver disease.
Positive influence of nuts
A fatty liver and nuts, which are known to be high in fat: How does that fit together? Nuts have a positive effect on inflammatory processes, insulin resistance and oxidative stress – a metabolic condition that helps to kill microorganisms but also attacks cell structures. Nuts are rich in nutrients and score points in the diet with vegetable protein, unsaturated fatty acids, dietary fiber, minerals and vitamins. Almonds, walnuts, pistachios and the like also help to prevent high blood pressure and should therefore be a regular part of your diet if you are overweight.
Lack of targeted treatment options
“Because there are still no targeted treatment options for fatty liver, all measures that have a positive influence on the disease are helpful. Many patients also suffer from concomitant diseases such as diabetes or high blood pressure. Because the influence of nuts on inflammatory processes, oxidative stress and insulin resistance is well known, we wanted to find out whether patients with fatty liver could benefit specifically by including more nuts in their diet,” explains USZ cardiologist David Niederseer, who was in charge of the study together with Christian Datz from the Oberndorf Clinic near Salzburg.
Nutritional analysis from alcohol to plums
For this purpose, 4655 people who participated in an Austrian colorectal cancer screening program between 2010 and 2019 were recorded, 2395 of whom were men. The mean age of the study participants was 58.5 years. Most of them had one or more pre-existing conditions such as high blood pressure, diabetes or cardiovascular problems. Patients with existing liver disease were excluded from the study, as were people with increased alcohol consumption. The group thus formed was a representative example of a general population.
Clinical data such as blood pressure, laboratory values and body mass were collected from the participants and they were comprehensively questioned about their eating habits: from alcohol consumption, fast food, meat, vegetables and fruit to sweet drinks and coffee, and of course the consumption of nuts was recorded. 2502 people stated that they never ate nuts or only ate them once a week, 1506 ate up to six portions a week and 142 people stated that they ate several portions a day. The liver of all study participants was examined by ultrasound according to established criteria.
Less fatty livers among nut fans
For example, 48.1 percent of people who never or only once a week ate nuts were diagnosed with fatty liver, 40.7 percent of moderate nut eaters, and 34 percent of participants who ate nuts several times a day. Fatty liver was significantly less common in the nut fans than in the other two groups. All groups, including the low nut eaters, showed fewer tissue changes than the non-nut eaters. There was only a slight difference between men and women.
“We are still at the beginning here and the significance of the study is certainly limited due to the design. However, it gives us sound evidence that there is a connection between nut consumption and the development of a fatty liver. The data suggest that nuts also cause less or less severe inflammation in the liver. We do not yet know why this is the case. Nor can we formulate any direct recommendations. However, we know from the study that it is worth investigating lifestyle measures, including diet, for the prevention of fatty liver in greater depth,” says David Niederseer, summarizing the results.
Publication
Nut consumption and the prevalence and severity of non-alcoholic fatty liver disease. DOI: 10.1371/journal.pone.0244514
