Evaluating the Anti-Oxidant and Anti-Inflammatory Properties of Watercress Supplementation at Short-Term Follow-Up: A Systematic Review of Randomized Controlled Trials.

Watercress (WC) has been used extensively in traditional medicine for various healthcare conditions such as hypertension, hyperglycemia, arthritis, and more. This systematic review evaluates WC's antioxidant and anti-inflammatory markers in human studies. A systematic review search was conducted in PubMed, Embase, and Cochrane Library for studies reporting anti-inflammatory and anti-oxidative markers following WC supplementation, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Study variables included the number of patients, dosage/formulation of WC, mean age, and follow-up time, pre- and post-intervention antioxidant/anti-inflammatory outcomes, and complications. Seven RCTs, including 302 patients with a mean age of 47 years (23-61) and a mean follow-up time of 39 days (21-60), were included in this study. The dosage varied from 85 g/day to 750 mg/kg/day. Antioxidant parameters reported included superoxide dismutase (five studies), ferric-reducing antioxidant power (two studies), glutathione peroxidase (two studies), retinol (two studies), β-carotene (two studies), and α-tocopherol (two studies). Oxidative stress parameters included protein carbonyls (four studies), thiobarbituric acid reactive substances (two studies), malondialdehyde (two studies), nitric oxide (two studies), T-SH (two studies), and CAT (three studies). Inflammatory markers included two studies reporting on tumor necrosis factor-a (two studies) and one study reporting on interleukin-1, interleukin-6, and C-reactive protein. WC administration demonstrated improvement for most antioxidant and anti-inflammatory markers and had a strong safety profile. WC had a positive effect on anti-oxidant and anti-inflammatory markers. However, the relatively short follow-up times and heterogeneous patient demographics and formulations/dosages of WC warrant further studies to assess the benefits of WC.