Across 16 randomized controlled trials encompassing 953 patients (mean age 35.27 years), Nrf2-activating compounds added to standard antipsychotics produced measurable but inconsistent benefits. Curcumin showed a standardized mean difference of -0.53 on overall symptom scales and significantly reduced positive symptoms, negative symptoms, and PANSS-G subscores—though wide confidence intervals and non-significant subgroup analyses undermine confidence in these effects. Sulforaphane demonstrated lower all-cause discontinuation rates than placebo and meaningfully reduced total cholesterol, LDL, and triglycerides, a clinically relevant finding given that antipsychotics frequently worsen metabolic profiles.
The Nrf2 pathway—a master regulator of antioxidant and anti-inflammatory gene expression—has been implicated in schizophrenia pathophysiology for over a decade, with oxidative stress increasingly recognized as a contributor to both symptom burden and cognitive deterioration. This meta-analysis is confirmatory rather than paradigm-shifting, adding statistical weight to small prior trials without resolving their core limitations. The pooled sample of under 1,000 patients across heterogeneous formulations, dosing regimens, and co-interventions makes definitive clinical guidance premature. Sulforaphane's metabolic benefits deserve particular attention for long-term schizophrenia management, where cardiovascular risk is a leading cause of reduced life expectancy. The inability to meta-analyze ascorbic acid or resveratrol due to data insufficiency highlights how underpowered this research domain remains. Larger, standardized trials with longer follow-up periods are needed before Nrf2 activators enter routine clinical protocols.
