Evidence supporting the use of: Sodium Benzoate
For the health condition: Schizophrenia
Synopsis
Source of validity: Scientific
Rating (out of 5): 2
Sodium benzoate, a common food preservative, has been investigated as an adjunctive treatment in schizophrenia based on its role as a D-amino acid oxidase (DAAO) inhibitor. By inhibiting DAAO, sodium benzoate is thought to increase levels of D-serine, an endogenous co-agonist at the NMDA receptor, thereby enhancing NMDA receptor function. NMDA receptor hypofunction is implicated in the pathophysiology of schizophrenia, particularly in cognitive and negative symptoms, which are poorly addressed by standard antipsychotics.
A few randomized, double-blind, placebo-controlled trials (notably Lane et al., 2013; Lin et al., 2014) have found that adjunctive sodium benzoate (typically 1g/day) can improve schizophrenia symptoms, especially negative and cognitive symptoms, compared to placebo. However, these studies have small sample sizes and short durations (up to 6 weeks). Subsequent research has produced mixed results. Some studies report that sodium benzoate is well-tolerated and may offer modest benefit, while others have not replicated the findings or have shown minimal effect.
Overall, there is preliminary scientific evidence supporting sodium benzoate as a potential adjunct in schizophrenia, but the strength of evidence is limited (rated 2/5). Larger, longer-term studies are needed to confirm efficacy and safety. It is not a standard or approved treatment, and its use should be limited to research settings.
