Effect of Amla (Emblica officinalis) Juice Supplementation on Serum Antioxidant Status in Healthy Volunteers: A Single-Group Pre–Post Study

Abstract

Background: Oxidative stress, an imbalance between reactive oxygen species and endogenous antioxidant defences, is implicated in the pathogenesis of cardiovascular, metabolic, neurodegenerative and other chronic non-communicable diseases. Amla (Emblica officinalis; syn. Phyllanthus emblica), a fruit deeply embedded in the Ayurvedic and Siddha traditions of South India, is exceptionally rich in vitamin C and hydrolysable-tannin polyphenols and is a plausible low-cost dietary antioxidant. Direct human data on its effect on serum antioxidant status remain limited.

Objective: To estimate the change in serum enzymatic and non-enzymatic antioxidant markers and a lipid-peroxidation marker after eight weeks of amla juice supplementation in healthy adults.

Methods: In this single-group pre–post interventional study, 50 healthy adult volunteers (31 male, 19 female; mean age 33.4 ± 9.9 years) consumed 30 mL/day of fresh amla juice for 8 weeks. Serum total antioxidant capacity (TAC), superoxide dismutase (SOD), catalase, reduced glutathione (GSH), malondialdehyde (MDA) and vitamin C were measured before and after the intervention by standard methods. Paired t-tests, 95% confidence intervals (CI) and Cohen's dz were computed.

Results: Adherence averaged 91.2%. All antioxidant defence markers rose significantly: TAC 1.232→1.472 mmol/L (+0.240; 95% CI 0.221–0.259), SOD 7.871→9.524 U/mL (+1.653; 1.528–1.778), catalase 41.610→49.840 kU/L (+8.230; 7.687–8.773), GSH 4.518→5.303 mg/dL (+0.786; 0.719–0.852) and vitamin C 0.711→0.960 mg/dL (+0.249; 0.225–0.273); all p<0.001. MDA fell from 4.738 to 3.790 nmol/mL (−0.948; 95% CI −1.037 to −0.859; p<0.001), indicating reduced lipid peroxidation. Effect sizes were large (dz 2.96–4.31). Only mild, self-limiting adverse effects occurred (12/50, 24%); there were no serious events and no discontinuations.

Conclusion: Eight weeks of amla juice was associated with significantly enhanced enzymatic and non-enzymatic antioxidant defences and reduced lipid peroxidation, consistent with amla's high vitamin C and polyphenol content.