Train promotes a wholesome life and a wholesome liver
PICTURE: Researchers at Tsukuba University have shown that an exercise program reduces liver steatosis and stiffness in patients with non-alcoholic fatty liver. These advances in liver health are … view More
Credit: Tsukuba University
Tsukuba, Japan – Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease in the world, affecting up to a quarter of human beings. It is characterized by the accumulation of fat in liver cells and can lead to inflammation, cirrhosis, and liver failure. Now, researchers at Tsukuba University are showing the beneficial effects of exercise on the liver beyond its expected weight loss benefits.
NAFLD has been linked to unhealthy behaviors such as overeating and a sedentary lifestyle. In Japan, 41% of middle-aged men have NAFLD and 25% develop non-alcoholic steatohepatitis (NASH) and liver dysfunction.
Weight loss is fundamental to NAFLD management. Unfortunately, it is difficult to achieve a targeted body weight without supervision and maintain it even more over time. To date, exercise has been viewed as a supplement to dietary restrictions for weight loss, but the other benefits such as reduced liver steatosis (changes in fat) and stiffness are increasingly recognized. However, the underlying mechanisms remain unclear.
“We compared data from obese Japanese men with NAFLD over a 3-month exercise program with those on diet restrictions aimed at weight loss,” said senior author Professor Junichi Shoda. “We followed liver parameters, reduction of adipose tissue, increase in muscle strength, reduction of inflammation and oxidative stress, changes in organokine concentrations and expression of the target genes of Nrf2, a sensor for oxidative stress.”
The researchers found that exercising maintained muscle mass better, albeit with a modest decrease in body and fat mass. Notably, ultrasound elastography showed that the exercise program reduced liver steatosis by an additional 9.5%, liver stiffness by an additional 6.8%, and FibroScan AST score (a measure of liver fibrosis) by an additional 16.4% over weight loss. Program reduced.
In addition, the exercise program altered circulating levels of specific organokines and apparently induced anti-inflammatory and antioxidant stress responses by activating Nrf2 (nuclear factor E2-related factor 2), a sensor of oxidative stress. It also improves the phagocytic capacity of Kupffer cells, which help maintain liver function.
Professor Shoda explains the relevance of their results. “Our research shows how exercise prevents liver steatosis and fibrosis in NAFLD and shows that this benefit is amplified by maintaining muscle mass and is independent of weight changes. Patients on exercise programs can become demotivated and discontinued unless they experience significant weight loss.” Therefore, moderate to vigorous exercise should be incorporated into all NAFLD regimen, and patients at risk for NASH should be encouraged to persevere with moderate to high-intensity exercise, whether or not they lose weight. ”
The article “Weight loss independent benefits of exercise in liver steatosis and stiffness in Japanese men with NAFLD” was published in JHEP Reports (2021) under DOI: https://doi.org/10.1016/j.jhepr.2021.100253.
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