Effects of Pomegranate (Punica granatum L.) Peel Extract Supplementation on Markers of Inflammation and Serum Matrix Metalloproteinase 1 in Women With Knee Osteoarthritis: A Randomized Double-Blind Placebo-Controlled Study

Rafraf M, Haghighian MK, Molani-Gol R, Hemmati S, Asghari Jafarabadi M · Nutrition and Metabolism Insights

All four markers fell within the extract group over eight weeks — hs-CRP by 38.2%, MMP-1 by 28.6%, NF-κB by 10.7%, MCP-1 by 2.6% — while NF-κB rose within the placebo group (p = 0.002). Between the groups the unadjusted week-8 comparison was null on every marker (p = 0.069 to 0.533). The separation the paper reports comes from an ANCOVA on log-transformed values adjusted for baseline, weight change, energy intake, physical activity, disease duration and parity: hs-CRP p = 0.045, NF-κB p = 0.002, MCP-1 p = 0.040, MMP-1 p = 0.003.

Population

66 women aged 38-60 with mild to moderate knee osteoarthritis and a BMI of 30-35, in Tabriz, Iran, all also taking glucosamine 500 mg and acetaminophen 1 g daily; 30 per group completed

Intervention

500 mg pomegranate peel extract, 90% ellagic acid, twice daily for 8 weeks

Comparator

Rice-flour placebo

Limitations

Peel extract in a capsule, not the fruit or the juice — the dose is not reachable by eating pomegranate. Women only, all obese, all on concurrent drug therapy, 8 weeks, and every endpoint in this paper is a blood marker; the same trial's symptom and metabolic data were published separately. The whole result rests on the covariate adjustment: no marker differed between the groups on the unadjusted comparison. Randomisation left the extract group eating markedly more carbohydrate at baseline and at week 8, which the paper sets aside on the ground that intakes did not change during the study. The abstract and results text give the four adjusted p-values against different markers than the table does. Run in 2014 and published in 2024, funded by Tabriz University of Medical Sciences from a PhD dataset, with no conflicts declared.