Dietary sugar and polyunsaturated fatty acid consumption as predictors of severity of schizophrenia symptoms.

A previous epidemiological study found an association between high sugar consumption and two year outcome of schizophrenia. The primary aim of the present pilot study was to assess the possible relationship between dietary sugar intake and the severity of schizophrenic symptoms in a group of 20 patients. A significant negative correlation (r = -0.54, p = 0.02) between dietary sugar and severity of schizophrenic symptoms, appears to be confounded by the effect of medication. Patients taking the antipsychotic drug clozapine consumed almost twice as much sugar as those taking other antipsychotic agents, (235.4+/-92.6 g/day versus 143+/-59, p = 0.02) and had less severe symptoms. Consumption of other nutrients showed no association with clozapine treatment. In a secondary analysis, severity of schizophrenic symptoms correlated with dietary intake of polyunsaturated fatty acids (r = -0.54, p = 0.02) and this was independent of the effect of medication. This finding is consistent with earlier studies.