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New research suggests that 150-300 minutes of exercise a week can help significantly reduce liver fat for those who are living with nonalcoholic fatty liver disease. Andriy Bezuglov/Stocksy
  • It’s recommended that adults should get between 150-300 minutes of exercise each week.
  • Previous research suggests this can help improve health in areas ranging from heart disease to quality of sleep.
  • New research suggests this can also help to significantly reduce liver fat for those who are living with nonalcoholic fatty liver disease (NAFLD).

The U.S. Department of Health and Human Services currently recommends adults should do at least 150 to 300 minutes of moderate to intense aerobic physical activity each week to best benefit their overall health and well-being.

This can pay great dividends for everything from heart health to the quality of one’s sleep.

Now, new research out of Penn State reveals that adhering to these recommended guidelines can significantly reduce one’s level of liver fat for those who have nonalcoholic fatty liver disease (NAFLD).

This is a condition where fatty tissue builds up in a person’s liver even if they drink little to no alcohol throughout their lives. Serious forms of this condition can lead to cirrhosis.

Researchers behind the study say this work is important because it outlines a clearly defined amount of exercise one might need to achieve a significant improvement in fatty liver tissue.

It underscores yet another reason why incorporating just moderate amounts of exercise in your weekly routine can have a positive ripple effect on your overall health.

This new research was published in The American Journal of Gastroenterology. A meta-analysis of 14 previously published studies, this research looked at data on a total of 551 people surveyed who all had NAFLD and enrolled in randomized, controlled exercise interventions, according to a press release.

The data included a range of information from the participants in the various studies, taking into account their age, sex, body mass index, shifts in body weight over time, MRI-measured liver fat, and their ability to keep up with the prescribed exercise regimen of the given study.

They discovered that exercise was 3.5 times more likely to result in greater than or equivalent to a 30% relative reduction in MRI-measured liver fat levels compared to standard, non-exercise-centric treatment for NAFLD.

Additionally, their secondary analysis was to concretely determine what the best “dose” of physical activity was to lead to clinically meaningful improvements in liver fat levels.

The results?

The team’s analysis revealed 39% of those people who were prescribed “greater than or equal to 750 metabolic equivalents of task” — think 150 minutes each week of something like a brisk walk — resulted in “significant treatment response” compared to just 26% of those who were prescribed a lesser exercise regimen.

The researchers note that this 150-minute standard for moderate weekly physical activity is not just the same activity recommended by the American Gastroenterological Association, but also the European Association for the Study of the Liver.

“Going into this study, it was well accepted that exercise training effectively reduces liver fat. What we didn’t expect to find was that exercise training was 3.5 times more likely to achieve clinically meaningful reductions in MRI-measured liver fat compared to standard clinical care as this had not been investigated to date,” lead study author Dr. Jonathan Stine, associate professor of medicine and public health sciences, and transplant hepatologist at Penn State Health Milton S. Hershey Medical Center, told Healthline.

When asked about the broader implications of his research, Stine explained that exercise is key to the clinical management of NAFLD “and should be discussed at each and every healthcare visit in both the primary care and specialist setting.”

“Our work highlights a novel way to approach this important topic by suggesting that the goal of exercise training in patients with NAFLD should no longer be to lose body weight, but rather to improve their NAFLD, physical fitness and overall health,” Stine said.

There are two types of NAFLD, when this fatty liver tissue builds up without the presence of excessive alcohol consumption over time.

There is nonalcoholic fatty liver (NAFL), where fat collects in the liver but there is little-to-no inflammation or liver damage. Generally, this does not progress or ultimately cause liver damage or further complications.

This can result in enlargement of the liver or pain, according to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDKK).

The other form is nonalcoholic steatohepatitis (NASH), when a person will have inflammation of the liver and experience liver damage. This can result in scarring of the liver, or fibrosis, and might also result in cirrhosis, which can ultimately lead to liver cancer.

Usually, you might develop one type of NAFLD over the other, but some people might start out with one form and later be diagnosed with the other, according to the NIDKK.

They report that NAFLD is one of the most common causes of liver disease in the United States, with the majority of people who have it being diagnosed with NAFL. It is estimated that 24% of adults nationwide have NAFLD and 1.5% to 6.5% have NASH.

Including children, NAFLD affects about 30% of the U.S. population, Dr.Jamile Wakim-Fleming,
director of the Fatty Liver Disease Medical Home Program at Cleveland Clinic, told Healthline.

Wakim-Fleming, who is unaffiliated with the Penn State research, said that NAFLD has doubled in frequency from where it was 15 to 20 years ago.

“It continues to rise and has worsened by the COVID epidemic. Currently, there is no FDA-approved therapy for fatty liver,” she explained. “Diagnosis requires imaging studies, noninvasive markers to detect fat and fibrosis in the liver, and at times a liver biopsy.”

When asked what are the best methods to treat it, in addition to, or outside of the 150 recommended minutes of weekly exercise, she said that, in general, diet and/or exercise “are effective in treating fatty liver.”

Additionally, medications do exist to decrease liver inflammation and there are methods of weight loss that help a person lose weight and the “excess fat from the body overall and also from the liver,” Wakim-Fleming added.

Stine said that a Mediterranean-based diet that is high in fruits, vegetables, bread and grains, potatoes, beans, nuts and seeds, and that also incorporates olive oil as a main source of fat can contribute to decreasing one’s liver fat.

“This [diet] can possibly be augmented by consuming additional green polyphenols such as those found in Mankai or walnuts,” he added. “Avoiding high fructose corn syrup is also a must.”

When asked about the effectiveness of the kinds of exercise behaviors outlined by this recent study, Wakim-Fleming said that weight loss paired with diet and exercise has traditionally been reported to improve fat and stiffness or fibrosis in the liver.

She said that a loss of roughly more than 5% and 10% of weight has been tied “to loss of fat and regression of fibrosis in the liver and has been the recommendation by most societies.”

“A recent body of evidence started to show that exercise alone is associated with benefits to the liver. These benefits are related to a complex mechanism of actions in the liver through modifications of inter-organ crosstalk characterized by improvements in organokine [a cytokine that works to regulate the an organ’s cells] imbalance and reductions in inflammation and oxidative stress,” Wakim-Fleming added. “Basically, the exercising body uses energy from its stores of carbohydrates and fat during longer interval. Such as seen in aerobic exercise for at least 30 min a week for at least 3 months.”

Stine said that exercise is a useful tool in treating NAFLD because it “stimulates many different biological pathways simultaneously and possibly synergistically.”

Every exercise program results in a person’s body getting used to that regimen as they progress in their training, he explained.

Exercise might result in a reduction in liver fat by “modifying pathways in the body involved in lipogenesis by down-regulating them and decreasing the amount of fat produced and stored in the liver as well as offering the potential to modify the gut-liver axis and change the bacteria found in a person’s intestines and the products these bacteria produce,” Stine added.

For those reading wondering about whether exercise is the way to go, Stine said that this kind of physical activity shifts how the body responds to insulin.

This in turn improves one’s “insulin resistance and insulin sensitivity” which would be expected to result in reductions in liver fat.

Wakim-Fleming said that studies do not always align on exactly how much physical activity can be recommended to impact liver fat. She said some point to the 150-minute marker that Stine’s research highlights over the course of three days. She said others point to the higher end of 300 minutes each week.

But exactly what kind of exercise works best? She suggested simple aerobic activities like going for a walk.

Moderate intensity resistance training where 70% of maximum heart rate is reached is also “beneficial in losing the fat and building the muscle which is the other fat burner,” Wakim-Fleming added.

“Benefits of aerobic exercise is that it is sustained and one can do it for 30 min or more, whereas intense exercise such as weightlifting is usually not sustained for longer periods,” she said.

Stine said that there is no one-size-fits-all approach and that anymoderate-intensity physical activity is good in this instance.

“No one type of activity has been shown to be more efficacious than another in reducing liver fat,” he said. “Patients can choose to walk, jog, bike, swim, or even resistance train.”