Plain language summary
The use of fructose in the food industry may have contributed to the increase in non-alcoholic fatty liver disease (NAFLD) in the general population. Consequently, obesity and associated comorbidities like type 2 diabetes, dyslipidaemia, NAFLD, and cardiovascular disease have increased. Although glucose and fructose are both sugars, they are metabolised differently by the body. The overfeeding of fructose may contribute to steatosis or accumulation of fat in the liver than glucose. The aim of this randomised, double-blind trial was to measure intrahepatic lipid content in 44 overweight subjects with high fatty liver index following fructose restriction for six weeks. In this study, fructose restriction resulted in a small but significant reduction in intrahepatic lipid content with a small effect size of 0.7% point. Fructose restriction did not seem to affect glucose tolerance, serum lipid concentration or HOMA-IR, variables related to intrahepatic lipid content. As a supplement, fructose may have a different metabolic profile than when taken as a food component. The study found no effect on glucose tolerance or serum lipid levels. The results of this study may help healthcare professionals to comprehend the role of fructose in steatosis and NAFLD.
Abstract
BACKGROUND There is an ongoing debate on whether fructose plays a role in the development of nonalcoholic fatty liver disease. OBJECTIVES The aim of this study was to investigate the effects of fructose restriction on intrahepatic lipid (IHL) content in a double-blind randomized controlled trial using an isocaloric comparator. METHODS Between March 2017 and October 2019, 44 adult overweight individuals with a fatty liver index ≥ 60 consumed a 6-wk fructose-restricted diet (<7.5 g/meal and <10 g/d) and were randomly assigned to supplementation with sachets of glucose (= intervention group) or fructose (= control group) 3 times daily. Participants and assessors were blinded to the allocation. IHL content, assessed by proton magnetic resonance spectroscopy, was the primary outcome and glucose tolerance and serum lipids were the secondary outcomes. All measurements were conducted in Maastricht University Medical Center. RESULTS Thirty-seven participants completed the study protocol. After 6 wk of fructose restriction, dietary fructose intake and urinary fructose excretion were significantly lower in the intervention group (difference: -57.0 g/d; 95% CI: -77.9, -39.5 g/d; and -38.8 μmol/d; 95% CI: -91.2, -10.7 μmol/d, respectively). Although IHL content decreased in both the intervention and control groups (P < 0.001 and P = 0.003, respectively), the change in IHL content was more pronounced in the intervention group (difference: -0.7% point, 95% CI: -2.0, -0.03% point). The changes in glucose tolerance and serum lipids were not significantly different between groups. CONCLUSIONS Six weeks of fructose restriction per se led to a small, but statistically significant, decrease in IHL content in comparison with an isocaloric control group.This trial was registered at clinicaltrials.gov as NCT03067428.
Methodological quality
Jadad score
:
5
Allocation concealment
:
Yes
