Effects of fructose restriction on blood pressure: Secondary analysis of a double-blind randomized controlled trial

Background: Despite convincing animal data, there is an ongoing debate on whether and how fructose affects blood pressure in humans. The aim of this study was to investigate the effects of fructose restriction on blood pressure, and the role of endothelial function herein. Methods: forty-four overweight individuals were asked to follow a fructose-restricted diet (<7.5 g/meal and <10 g/day) for 6 weeks. They were randomly assigned to double-blind supplementation with glucose (=intervention group) or fructose (=control group) powder three times daily. Office blood pressure was measured with an automated device, and endothelial function was assessed by reactive hyperemia peripheral arterial tonometry, skin laser doppler flowmetry, and serum sE-selectin. Results: Thirty-seven participants completed the study. Systolic blood pressure decreased significantly in the intervention group (change from baseline: −3.3 mmHg; 95%CI:-8.8,– 0.3), but this change was not statistically different from the control group. In contrast, diastolic blood pressure decreased significantly in the intervention group in comparison to controls (difference: −4.0 mmHg; 95%CI:-9.5,-0.5). Furthermore, the change in fructose intake was associated with the change in diastolic blood pressure (beta: 0.085 mmHg; 95% CI: 0.032;0.138). The endothelial markers were not affected by the intervention. Finally, the effects of the intervention on diastolic blood pressure appeared to be higher in individuals consuming high amounts of salt at baseline (difference: −9.0 mmHg; 95%CI:-14.5,-2.5). Conclusions: Six-week fructose restriction per se results in a dose-dependent decrease in diastolic blood pressure. Further studies are warranted to elucidate the effects of fructose restriction on salt-sensitive hypertension in humans. Trial registration: www.clinicaltrials.gov; NCT03067428.