Dietary patterns and schizophrenia: a comparison with healthy controls

Abstract

BackgroundIt has been reported that the onset of schizophrenia and the physical complications after its onset are related to diet. Diet has been considered as a variable factor of the pathogenesis of schizophrenia. However, the results of studies on this relationship have been inconsistent. Nutrients are consumed as a mixture in the diet. It is difficult to study them in isolation because they may have mutually complementary effects. The aim of this study was to assess the association between dietary patterns and schizophrenia in Japan.MethodsThe subjects comprised 237 outpatients aged 30–60 years (123 males and 114 females) with diagnoses of either schizophrenia or schizoaffective disorder. The patient diagnoses were determined based on medical records. Patients were recruited between June 2011 and August 2011. As a reference group, 404 healthy volunteers aged 30–60 years (158 males and 246 females) were also included. Demographic data (age, sex, and level of education) were collected by face-to-face method interviews and self-administered questionnaires. We assessed eating habits over the last month using a validated brief self-administered diet history questionnaire. We detected dietary patterns through a principal component analysis of calorie-adjusted intake; two principal components were retained. The principal components for each dietary pattern and for each individual were divided into tertiles by principal component scores.ResultsWe derived two dietary patterns by principal component analysis; namely, the “vegetable” dietary pattern and the “cereal” dietary pattern. In the “cereal” dietary pattern, the high tertile was associated with a significantly increased risk of schizophrenia (P<0.001).ConclusionThe “cereal” dietary pattern is associated with schizophrenia. This article is the first to describe a study examining the association of dietary pattern and schizophrenia.

Dietary intake of people with severe mental illness: systematic review and meta-analysis

“…A ‘cereal’ dietary pattern (bread, rice, confectionary etc.) was positively associated with schizophrenia whereas a ‘vegetable’ dietary pattern was not 72 . Higher energy intake, and lower protein intake, were positively associated with general symptom severity in early psychosis in one study, 51 whereas life stress was positively associated with increased refined sugar intake in people experiencing psychosis but negatively associated with refined sugar intake in both high-risk for psychosis and healthy participants, in the same study.…”

“…Results for macronutrients and micronutrients were mixed when compared with reference groups and recommended intakes, with no clear findings emerging. There were trends for studies to find lower mono- and polyunsaturated fats, 24 , 28 , 29 , 55 and higher intakes of total and saturated fat 51 , 54 , 57 , 64 , 65 , 72 and trans-fats 55 in the SMI groups when compared with a comparator (control or population data). In addition, higher sugar intake was found in two studies 57 , 72 …”

“…was positively associated with schizophrenia whereas a 'vegetable' dietary pattern was not. 72 Higher energy intake, and lower protein intake, were positively associated with general symptom severity in early psychosis in one study, 51 whereas life stress was positively associated with increased refined sugar intake in people experiencing psychosis but negatively associated with refined sugar intake in both high-risk for psychosis and healthy participants, in the same study. A fourth study in Japan found men who had infrequent intakes of vegetables, mayonnaise, potatoes, soy products, seaweed and fish products had more pronounced psychiatric symptoms, although this correlation was not found in women.…”

“…In addition, higher sugar intake was found in two studies. 57,72 Results for fibre intakes were mixed when compared with controls or population data, although the SMI group consumed less than the national/region recommendations in nine studies 24,29,42,44,47,50,54,65,68 and adequate intake in one study. 55 For caffeine intake, five studies found higher caffeine intakes, or high caffeine intakes (≥200 mg/day), to be more frequent in the SMI group compared with the reference group 19,37,44,65,66 and one study found no difference.…”

The Gut-Brain Axis, BDNF, NMDA and CNS Disorders

“…The carbohydrate and fat content is again particularly important [204] and patients with schizophrenia exhibit large increases in central BDNF in response to 25 feeding low calorific diets. High cereal diets have also been linked with psychotic behaviour [205] and specific dietary components such as curcumin [206] and polyphenols [203] have been identified as compounds mediating some of these effects [207].…”