People with non-alcoholic fatty liver disease (also known as non-alcoholic steatohepatitis (NASH)) benefit from exercise regardless of whether they lose weight, say Australian and UK researchers.
NASH is a condition where fat infiltrates the liver and the build-up of fat causes inflammation. There are no drug therapies for NASH, and lifestyle changes are the only effective treatment for the disease. But until now it hasn’t been clear whether weight loss is the underlying driver of change or whether exercise on its own can lead to improvements.
The study allocated 24 mainly sedentary people with NASH to either a 12-week exercise program or to usual care. Crucially, the people in the study were told not to change their diet and to maintain their baseline body weight.
Those following the exercise program – which entailed cycling and resistance training 3 days a week – experienced reductions of 16% in their liver fat and 12% in visceral fat (the fat that’s stored in the abdominal cavity around your organs), as well as a 23% drop in circulating triglycerides (a product of the breakdown of fats).
By contrast, in the group that continued with usual care, all these indicators ticked up.
Visceral fat is directly linked to liver inflammation and fibrosis (scarring of the liver – the first stage before cirrhosis) note the researchers from the University of Adelaide and the UK’s Newcastle University.
The exercise group also had reductions in CK-18, a defining pathological feature of NASH.
But other inflammatory biomarkers remained stable, and there was no change in liver enzymes.
That lack of change in liver enzymes probably means exercise without weight loss won’t be enough to prevent liver fibrosis on its own, the researchers caution.
But they note that sustaining weight loss over the long term is notoriously difficult. Exercise without weight loss could be an alternative strategy for patients who find it too hard to shed the pounds, they say.