Sodium Benzoate Helps Treat Schizophrenia When Added to Clozapine
In a 2017 article in the journal Biological Psychiatry, Chieh-Hsin Lin and colleagues reported that sodium benzoate, a common food preservative, may augment the effects of clozapine in patients with schizophrenia.
Clozapine is the most effective antipsychotic available, but as many as 40–70% of patients with treatment-resistant schizophrenia do not respond to it. For those with a poor response to clozapine, sodium benzoate may offer some hope.
In a randomized, double-blind trial, sixty inpatients taking clozapine for schizophrenia were divided into three groups. One group received an additional 1 g/day of sodium benzoate, another received 2 g/day, and the third received placebo in addition to clozapine. Both groups taking sodium benzoate and clozapine showed improvements in negative symptoms of schizophrenia (which can include apathy and inability to experience pleasure) compared to the group taking only clozapine. The larger 2g dose also improved positive symptoms of schizophrenia (such as hallucinations or delusions) and quality of life. Changes in levels of the antioxidant catalase were linked to the total improvement in symptoms and the improvement in positive symptoms. Sodium benzoate did not seem to cause any side effects.
Editor’s Note: Sodium benzoate is a D-amino acid oxidase inhibitor that activates NMDA receptors and increases levels of the amino acid D-serine in the brain by preventing it from breaking down. D-serine can reverse the effects of the illicit drug PCP, and very high doses of D-serine have improved the effectiveness of atypical antipsychotics in people with schizophrenia. By increasing levels of D-serine, sodium benzoate may offer new benefits to people with schizophrenia, especially those who have not responded to other treatments.
Cinnamon Improves Memory in Mice
A recent study found that mice that ate more cinnamon got better and faster at learning. In the study, published in the Journal of Neuroimmune Pharmacology in 2016, separated mice into good learners and poor learners based on how easily they navigated a maze to find food. After the poor learners were fed cinnamon for a month, they could find the food more than twice as quickly as before.
The benefits of cinnamon come from sodium benzoate, a chemical produced as the body breaks down the cinnamon. Sodium benzoate enters the brain and allows the hippocampus to create new neurons.
Feeding cinnamon to the poor learning mice normalized their levels of receptors for the neurotransmitter GABA, closing the gap with good learners. Sodium benzoate also improved the structural integrity of some brain cells. Cinnamon also can help sensitize insulin receptors.
Doctors hope these findings may eventually contribute to treatment research on Alzheimer’s and Parkinson’s diseases.
Cinnamon should be consumed in moderate quantities because the Chinese variety most commonly found in North American supermarkets has high levels of coumarin, a compound that can be toxic to the liver when consumed in large quantities. Ceylon (Sri Lankan) cinnamon has lower levels of coumarin.
