Beta-cryptoxanthin Supplementation and an Energy-Restricted High-Protein Diet Improved Metabolic Syndrome in Overweight or Obese Adults with Non-Alcoholic Fatty Liver Disease: A Randomized Controlled Trial

Objective: Despite the promising findings from experimental studies in different animals regarding the beneficial effects of β-cryptoxanthin (B-CX) or a high protein diet or both on metabolic syndrome components (also known as CMS components), randomized controlled trials conducted on this issue in humans are extremely scarce. A single-center, multi-arm, parallel-group, randomized controlled trial study design was applied.

Methods: In this 12 week period, ninety-two eligible overweight/obese adults with ultrasonographically confirmed NAFLD, were assigned to four groups as follow: HPD + placebo; normal protein diet +β-CX (NPD +β-CX); HPD +β-CX; and NPD + placebo (control group). Data on anthropometric measures, glycemic and lipidemic parameters, serum insulin, homoeostasis model-insulin resistance index (HOMA-IR), hemoglobin A1C (HbA1C), blood pressure were collected at the baseline and the end of the study. Dietary intake and physical activity level were also assessed.

Results: In all 86 of the patients completed the study and only 16 experienced minor adverse events. We observed improvement in all the metabolic syndrome components (also known as CMS components components) (all P<0.010), except blood pressure, prior to controlling confounding factors by one-way analysis of covariance models in the intention-to-treat population (N=92). But this model analysis revealed that Waist circumference (WC) and HbA1C were significant compared to the control group (P<0.010).

Conclusion: In line with the findings from animal studies, the results of the present research explain that an energy–restricted high protein diet (HPD) with β-cryptoxanthin (β-CX) were associated with improvement of lipid profile and HbA1C in NAFLD independent of BMI decrease, age, WC reduction or sex, as confounding factors.