Fructose, high-fructose corn syrup, sucrose, and nonalcoholic fatty liver disease or indexes of liver health: a systematic review and meta-analysis.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of intervention and observational studies
PubMed 25099546 · doi:10.3945/ajcn.114.086314
What was done
Systematic review of English-language human studies of any design in children and adults with low to no alcohol intake reporting at least one measure of liver health. The review assessed the effects of fructose, high-fructose corn syrup (HFCS), and sucrose on nonalcoholic fatty liver disease (NAFLD) and liver markers. Strength of evidence was evaluated using risk of bias, consistency, directness, and precision across 6 observational and 21 intervention studies.
What was found
The abstract provides no numerical effect estimates or confidence intervals. It found a low level of evidence that a hypercaloric pure-fructose diet increases liver fat and aspartate aminotransferase (AST) compared to a weight-maintenance diet in healthy men, and low-level evidence that hypercaloric fructose and glucose diets have similar effects on liver fat and enzymes. Evidence for observational studies and for HFCS or sucrose on NAFLD was rated insufficient. Associations between sugar intake and liver indices appeared confounded by excessive energy intake.
Why it matters
This review suggests that worsening liver health markers seen with high sugar intake are largely attributable to caloric excess rather than a unique hepatotoxic effect of specific sugars.
Limits
Nineteen of the 21 intervention trials included only healthy adults (mainly young men), with only one study in adults with NAFLD and one in children with NAFLD. Observational data had high risk of bias and inconsistent results, data on HFCS and sucrose were insufficient, and findings relied on indirect comparisons.
Cited by
- contradicts Dietary fructose is as dangerous to the liver as alcohol.