An energy-restricted high-protein diet supplemented with β-cryptoxanthin alleviated oxidative stress and inflammation in non-alcoholic fatty liver disease: A randomized controlled trial

Abstract The efficacy of β-cryptoxanthin (BCX), a high-protein diet (HPD), or both in reducing oxidative stress and inflammation in non-alcoholic fatty liver disease (NAFLD) has never been examined within a randomized controlled trial (RCT). Thus, we aimed to assess the efficacy of an energy-restricted HPD supplemented with BCX in alleviating these conditions in NAFLD in a RCT design. We hypothesized that this combination may improve oxidative stress and inflammation in NAFLD, as compared to a standard energy-restricted diet. Ninety-two ultrasonographically confirmed overweight/obese adult NAFLD patients attending an outpatient clinic in Ahvaz, Iran were recruited for this 12-week, single-center, parallel-group, double-blind RCT from 2017–2018. Subjects were randomized into four equal groups (n = 23): HPD-BCX (energy-restricted HPD + BCX), HPD (energy-restricted HPD + placebo), BCX (standard energy-restricted diet + BCX), and control (standard energy-restricted diet + placebo). Serum levels of oxidative stress- and inflammation-related markers, as primary outcome measures, were determined at baseline and at the study endpoint. The one-way analysis of covariance models in the intention-to-treat population (N = 92) showed that the HPD-BCX group achieved greater 12-week reductions in malondialdehyde (MDA), high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), and total cytokeratin-18 (CK18-M65), but higher increases in total antioxidant capacity (TAOC) and adiponectin, compared to the control group (mean differences for MDA, hs-CRP, IL-6, CK18-M65, TAOC, and adiponectin were: −1.9 nmol/mL, −1.0 mg/L, −2.0 ng/L, −270.9 ng/L, 2.5 U/mL, and 1.9 mg/L, respectively; all P