The exercise that could help reduce liver fat, according to scientists

About 150 minutes of moderate to intense aerobic physical activity every week can significantly reduce liver fat, according to a new review of studies.

The research, published recently in the American Journal of Gastroenterology, assessed 14 previous studies and found that this regimen of weekly exercise can lead to meaningful reductions in liver fat for patients with nonalcoholic fatty liver disease (NAFLD).

NAFLD affects nearly a third of the global population, and may lead to cirrhosis, also known as liver scarring, and cancer over time.

There are currently no approved drug treatments or an effective cure for this condition, but research has shown that exercise can improve liver fat, physical fitness, body composition, and quality of life for patients.

However, the specific amount of exercise needed to make clinically meaningful improvement remained unclear, say scientists, including those from Penn State Health in the US.

It has remained unclear until now the required “dose” of exercise that could help NAFLD patients achieve clinically meaningful improvement of at least a 30 per cent relative reduction of liver fat.

“Having a target amount of physical activity to aim for will be useful for health care and exercise professionals to develop personalized approaches as they help patients modify their lifestyles and become more physically active,” study co-author Jonathan Stine said in a statement.

“Our findings can give physicians the confidence to prescribe exercise as a treatment for nonalcoholic fatty liver disease,” Dr Stine said.

In the new analysis, scientists assessed 14 studies with a total of 551 subjects who had NAFLD and participated in randomised, controlled trials involving exercise interventions.

They evaluated the pooled data from all these studies including age, sex, body mass index, change in body weight, adherence to the exercise regimen, and liver fat levels measured from MRI scans.

The review of studies revealed that exercise training was about 3.5 times more likely to achieve clinically meaningful treatment response compared to standard clinical care.

“Independent of weight loss, exercise training is three and a half times more likely to achieve clinically meaningful treatment response in MRI-measured liver fat compared with standard clinical care,” researchers wrote in the study.

It found that about 40 per cent of patients prescribed greater than or equal to 750 metabolic equivalents of task, such as 150 minutes per week of brisk walking, achieved significant treatment response compared to only 26 per cent of those prescribed lesser doses of exercise.

This 150 minutes of moderate to intense weekly aerobic activity is the same amount of physical activity recommended by the American Gastroenterological Association and the European Association for the Study of the Liver.

Scientists suggest this amount of exercise may bring about clinically relevant reductions in MRI-measured liver fat at a rate similar to those reported in early-phase NASH drug trials evaluating medications that block fat production.

However, they also add that more studies, including controlled clinical trials are needed to validate the new findings and to compare the impact of different exercise “doses.”

“Exercise is a lifestyle modification, so the fact that it might match the ability of in-development therapeutics to achieve the same outcome is significant,” Dr Stine says.

“Clinicians counseling patients with NAFLD should recommend this amount of activity to their patients. Brisk walking or light cycling for 1/2 an hour a day five times a week is just one example of a program that would meet these criteria,” he added.