Effects of fructose restriction on liver steatosis (FRUITLESS); a double-blind randomized controlled trial.
Study Goal
The researchers aimed to investigate whether fructose restriction reduces intrahepatic lipid (IHL) content in overweight individuals with a high fatty liver index, comparing it to an isocaloric fructose-supplemented control group.
Results Summary
Fructose restriction led to a small but statistically significant decrease in IHL content compared to the control group, though both groups showed reductions. No significant differences were observed in glucose tolerance or serum lipids between groups.
Population
Overweight adults with a fatty liver index ≥ 60.
Effective Dosage
Fructose-restricted diet (<7.5 g/meal and <10 g/d), supplemented with glucose or fructose sachets 3 times daily.
Duration
6 weeks
Interactions
None mentioned
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
fructose-restricted diet (<7.5 g/meal and <10 g/d) with glucose supplementation | decrease | dietary fructose intake | adult overweight individuals with a fatty liver index ≥ 60 | -57.0 g/d; 95% CI: -77.9, -39.5 g/d | significantly lower | #1 |
fructose-restricted diet (<7.5 g/meal and <10 g/d) with glucose supplementation | decrease | urinary fructose excretion | adult overweight individuals with a fatty liver index ≥ 60 | -38.8 μmol/d; 95% CI: -91.2, -10.7 μmol/d | significantly lower | #2 |
fructose-restricted diet (<7.5 g/meal and <10 g/d) with glucose supplementation | decrease | intrahepatic lipid (IHL) content | adult overweight individuals with a fatty liver index ≥ 60 | P < 0.001 | decreased | #3 |
fructose-restricted diet (<7.5 g/meal and <10 g/d) with fructose supplementation | decrease | intrahepatic lipid (IHL) content | adult overweight individuals with a fatty liver index ≥ 60 | P = 0.003 | decreased | #4 |
fructose-restricted diet (<7.5 g/meal and <10 g/d) with glucose supplementation | decrease | intrahepatic lipid (IHL) content | adult overweight individuals with a fatty liver index ≥ 60 | -0.7% point, 95% CI: -2.0, -0.03% point | more pronounced decrease | #5 |
fructose-restricted diet (<7.5 g/meal and <10 g/d) with glucose supplementation | no change | glucose tolerance | adult overweight individuals with a fatty liver index ≥ 60 | - | not significantly different | #6 |
fructose-restricted diet (<7.5 g/meal and <10 g/d) with glucose supplementation | no change | serum lipids | adult overweight individuals with a fatty liver index ≥ 60 | - | not significantly different | #7 |
fructose restriction per se | decrease | intrahepatic lipid (IHL) content | adult overweight individuals with a fatty liver index ≥ 60 | - | led to a small, but statistically significant, decrease | #8 |
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.