Comparing fermented food and vitamin E on exercise-mediated Nrf2/ARE activation in middle-aged/ elderly: A randomized, double-blind clinical study

Abstract

Background: There is a compelling need to emphasize the importance of deepening the rationale behind functional foods research in molecular biology. Indeed, establishing stringent criteria to evaluate functional food interventions in disease prevention and as adjunctive therapeutic strategies offers significant opportunities for health promotion.

Objective: This study investigated the effects of fermented papaya preparation (FPP®) and vitamin E on gene expression in middle-aged/elderly individuals, leveraging FPP’s established antioxidant and immune-regulatory benefits. 

Methods: Graded Exercise Walking Test was administered twice weekly for 6 months. Total Antioxidant capacity (TAC) and gene expression (Nrf2, NQO1, HO-1) in PBMC were measured monthly. 

Results: Throughout the 6-month study, routine biochemistry and BMI remained stable. Both treatments significantly improved Total Antioxidant Capacity (TAC), Vitamin E exhibiting earlier effects (3 months). Notably, FPP® supplementation led to sustained over-expression of nuclear Nrf2 in all subjects, surpassing Vitamin E’s effects.  NQO1 gene expression was rapidly and consistently upregulated in the FPP group, exceeding baseline and Vitamin E levels throughout the study. HO-1 gene expression was upregulated by FPP at 1 month in younger age quartiles (Q1-2) and at 3 and 6 months in all subjects, regardless of age and gender. In contrast Vitamin E did not significantly impact Nrf2, NQO1, or HO-1 gene expression. 

Conclusion: These findings demonstrate that FPP, unlike Vitamin E, potentiates Nrf2 signaling, triggering a downstream epigenetic cascade. Notably, our clinical data reveal that physical exercise combined with functional food supplementation partially restores impaired Nrf2 signaling in elderly individuals.