The impact of a blend of Pistacia atlantica seed and canola oil compared with a blend of corn-canola oil with synthetic antioxidant and corn-canola oil without synthetic antioxidant on oxidative stress markers in patients with metabolic syndrome: protocol for a triple-blind, randomized, three-way cross-over clinical trial

BACKGROUND: Metabolic syndrome (MetS) is regarded as a complex metabolic disorder. Recently, the role of dietary antioxidants in the underlying pathogenesis and complications of MetS has come into focus. Pistacia atlantica oil is known as a high antioxidant oil which might improve the antioxidant status of dietary oils and also oxidative stress markers. On the other hand, tert-Butylhydroquinone (TBHQ) is an approved food-grade synthetic antioxidant that acts both as an inducer and inhibitor of carcinogenesis. The current trial will explore the possible effect of a blend of Pistacia atlantica seed-canola oils, corn-canola oils with TBHQ, and corn-canola oil without TBHQ on oxidative stress markers in patients with MetS. METHODS: We will conduct a single-center, triple-blind, three-way randomized cross-over clinical trial (RCT) among 72 patients with MetS. After a 1-month run-in period, eligible participants will consume the intervention oils as their regularly consumed oils in a random order. Each intervention period will last 8 weeks separated by 4-week washout periods. Anthropometric indices, body composition, physical activity, blood pressure, and 24-h dietary food recall measurements will be assessed at the beginning and the end of each intervention period. The primary outcome will be oxidative stress markers including serum total antioxidant capacity, total oxidant status, malondialdehyde, nitric oxide, and the enzyme activity of myeloperoxidase, superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase. The secondary outcomes will be changes in MetS components including blood pressure, fasting blood glucose, triglyceride, high-density lipoprotein cholesterol, and anthropometric measurements. DISCUSSION: Pistacia atlantica seed oil is high in antioxidants. An intervention with this oil could offer an option for oxidative stress prevention among patients with metabolic syndrome. The present clinical trial will be the first one assessing the impact of Pistacia atlantica oil on human oxidative stress markers. TRIAL REGISTRATION: Iranian Registry of Clinical trials IRCT20130223012571N8. Registered on 4 March 2022.