The effect of saffron supplementation on indices of oxidative stress, inflammation, mental health, and quality of life in patients with Parkinson's disease: a randomized, triple-blind, placebo-controlled clinical trial

<i>Background</i>: Regarding the antioxidant content of saffron, it could be beneficial for diseases linked to oxidative stress, such as Parkinson's disease (PD). However, there were limited human studies on the efficacy of saffron supplements on PD. Therefore, we aimed to investigate this subject. <i>Method</i>: The current study is a triple-blind, randomized, parallel clinical trial, which investigated the effect of 100 mg d^-1 saffron powder or placebo on 92 patients with PD for 12 weeks. The analyses were conducted based on an intention-to-treat approach. <i>Results</i>: The age and BMI (mean ± SE) were 68.36 ± 1.0 years and 27.09 ± 0.45 kg m^-2, respectively. Comparing the mean changes of the saffron and placebo groups confirmed significant favorable effects of saffron on C-reactive protein (CRP) values (adjusted mean difference: -3.84 mg L^-1 and 95% CI: -5.61, -2.08; <i>P</i>_ANCOVA < 0.001), distress (adjusted mean difference: -4.40 and 95% CI: -8.43, -0.37; <i>P</i>_ANCOVA = 0.03), anxiety (adjusted mean difference: -4.75 and 95% CI: -8.30, -1.20; <i>P</i>_ANCOVA = 0.009), depression (adjusted mean difference: -4.58 and 95% CI: -8.34, -0.81; <i>P</i>_ANCOVA = 0.01), cognitive status (adjusted mean difference: 0.78 and 95% CI: 0.16, 1.40; <i>P</i>_ANCOVA = 0.01), sleep quality (adjusted mean difference: 14.76 and 95% CI: 3.20, 26.32; <i>P</i>_ANCOVA = 0.01), fatigue (adjusted mean difference: -9.20 and 95% CI: -13.76, -4.65; <i>P</i>_ANCOVA < 0.001) and indices of quality of life including mobility (adjusted mean difference: -6.43 and 95% CI: -12.32, -0.54; <i>P</i>_ANCOVA = 0.03), daily activity (adjusted mean difference: -6.62 and 95% CI: -12.89, -0.34; <i>P</i>_ANCOVA = 0.03), cognitive impairment (adjusted mean difference: -8.07 and 95% CI: -14.39, -1.75; <i>P</i>_ANCOVA = 0.01), bodily discomfort (adjusted mean difference: -7.50 and 95% CI: -13.93, -1.06; <i>P</i>_ANCOVA = 0.02), and Parkinson's Disease Summary Index (PDSI) (adjusted mean difference: -4.86 and 95% CI: -7.48, -2.25; <i>P</i>_ANCOVA < 0.001). Additionally, the saffron group in comparison with the placebo group showed marginal decreases in the values of malondialdehyde (adjusted mean difference: -0.32 nmol mL^-1 and 95% CI: -0.69, 0.03; <i>P</i>_ANCOVA = 0.07). No side effect was observed in the groups. <i>Conclusion</i>: The current analysis confirmed the efficacy of 100 mg d^-1 saffron supplementation in patients with PD for 12 weeks. So, saffron supplementation could be a beneficial adjuvant therapy in the management of PD.