Dietary fatty acid and antioxidant intake in community-dwelling patients suffering from schizophrenia

Effects of Dietary Habits on General and Abdominal Obesity in Community-dwelling Patients with Schizophrenia

Objective

To investigate the effects of dietary habits on general and abdominal obesity in community-dwelling patients with schizophrenia spectrum disorder according to sex.

Methods

A total of 270 patients with schizophrenia spectrum disorder registered at mental health welfare centers and rehabilitation facilities were recruited. General obesity was defined as a body mass index ≥ 30 kg/m², and abdominal obesity was defined as a waist circumstance ≥ 90 cm in men and ≥ 85 cm in women. Dietary habits were evaluated using dietary guidelines published by the Korean Ministry of Health and Welfare. Demographic and clinical characteristics along with dietary habits and information related to obesity were collected. Factors related to obesity were evaluated separately by sex.

Results

Dietary habits differed according to sex, in that scores for healthy eating habits were lower in men than in women. In men, the prevalences of general and abdominal obesity were 17.0% and 37.3%, respectively. In women, the prevalences of general and abdominal obesity were 23.1% and 38.5%, respectively. Regression analysis showed that the scores of regular eating habits were negatively associated with general and abdominal obesity in men, and the scores of healthy eating habits were negatively associated with general and abdominal obesity in women.

Conclusion

Among patients with schizophrenia, regular eating habits might reduce the risk of obesity in men, and healthy eating habits might reduce the risk of obesity in women. Nutrition education should be provided to community- dwelling patients with schizophrenia to prevent obesity in this population.

Dissecting Causal Associations of Diet-Derived Circulating Antioxidants with Six Major Mental Disorders: A Mendelian Randomization Study

Although observational studies have suggested associations between circulating antioxidants and many mental disorders, causal inferences have not been confirmed. Mendelian randomization (MR) analyses were conducted using summary-level statistics from genome-wide association studies (GWASs) to explore whether genetically determined absolute circulating antioxidants (i.e., ascorbate, retinol, β-carotene, and lycopene) and metabolites (i.e., α- and γ-tocopherol, ascorbate, and retinol) were causally associated with the risk of six major mental disorders, including anxiety disorders (AD), major depressive disorder (MDD), bipolar disorder (BIP), schizophrenia (SCZ), post-traumatic stress disorder (PTSD), and obsessive-compulsive disorder (OCD). MR analyses were performed per specific-outcome databases, including the largest GWAS published to date (from 9725 for OCD to 413,466 for BIP participants), UK Biobank (over 370,000 participants), and FinnGen (over 270,000 participants), followed by meta-analyses. We found no significant evidence that genetically determined diet-derived circulating antioxidants were significantly causally associated with the risk of the six above-mentioned major mental disorders. For absolute antioxidant levels, the odds ratios (ORs) ranged from 0.91 (95% CI, 0.67-1.23) for the effect of β-carotene on OCD to 1.18 (95% CI, 0.90-1.54) for the effect of ascorbate on OCD. Similarly, for antioxidant metabolites, ORs ranged from 0.87 (95% CI, 0.55-1.38) for the effect of ascorbate on MDD to 1.08 (95% CI, 0.88-1.33) for the effect of ascorbate on OCD. Our study does not support significant causal associations of genetically determined diet-derived circulating antioxidants with the risk of major mental disorders.

Niacin skin flush and membrane polyunsaturated fatty acids in schizophrenia from the acute state to partial remission: a dynamic relationship

Despite the consistent finding of an attenuated niacin-induced flush response in schizophrenia, its long-term stability and relationship to the membrane polyunsaturated fatty acid (PUFA) levels remain unknown. We conducted niacin skin tests and measured the membrane PUFAs using gas chromatography among 46 schizophrenia inpatients and 37 healthy controls at the baseline and the 2-month follow-up. Attenuated flush responses were persistently observed in schizophrenia patients in both acute and partial remission states, whereas an increased flush response was found in the controls. A persistent decrease in both dihomo-gamma-linolenic acid and docosahexaenoic acid and an increased turnover of arachidonic acid (ARA) via endogenous biosynthesis were found in schizophrenia patients. A composite niacin flush score by combining those with a control-to-case ratio of >1.4 (i.e., scores at 5 min of 0.1 M, 0.01 M, and 0.001 M + 10 min of 0.01 M and 0.001 M + 15 min of 0.001 M) at the baseline was correlated positively with ARA levels among controls but not among schizophrenia patients, whereas the flush score at the 2-month follow-up was correlated positively with ARA levels among patients. The 2-month persistence of attenuated niacin-induced flush response in schizophrenia patients implies that the niacin skin test might tap a long-term vulnerability to schizophrenia beyond acute exacerbation.

The Association of the Gut Microbiota with Clinical Features in Schizophrenia

The connection between gut microbiota and schizophrenia has become a fertile area of research. The relationship is bidirectional and quite complex, but is likely to lead to practical clinical applications. For example, commensal microbiota have been shown to produce inflammatory metabolites that can cross the blood–brain barrier—a possible neurobiological precursor of psychosis. Antipsychotics that treat these individuals have been shown to alter gut microbiota. On the other hand, life style in schizophrenia, such as diet and decreased exercise, can be disruptive to the normal microbiome diversity. In the present paper, we conduct a review of PubMed literature focusing on the relationship of gut microbiota with clinical symptoms of schizophrenia, which, to our knowledge, has not yet been reviewed. Numerous clinical characteristics were identified correlating to gut microbial changes, such as violence, negative symptoms, treatment resistance, and global functioning. The most consistently demonstrated correlations to gut microbial changes across studies were for the overall symptom severity and negative symptom severity. Although numerous studies found changes in these domains, there is much variability between the bacteria that change in abundance between studies, likely due to the regional and methodological differences between studies. The current literature shows promising correlations between gut microbiota profiles and several clinical features of schizophrenia, but initial studies require replication.

Plasma bilirubin levels are reduced in first-episode psychosis patients and associates to working memory and duration of untreated psychosis

Schizophrenia is a severe mental disorder and one of its characteristics is cognitive impairments. Findings regarding levels of the heme metabolite and plasma antioxidant bilirubin in schizophrenia are inconclusive. However, a recently published study indicate that low levels of bilirubin may be implicated in the memory impairments seen in the disorder. The aim of this cross-sectional study was to investigate the levels of bilirubin in individuals with a first-episode psychosis (FEP) and to examine if bilirubin levels were associated to cognitive impairments, symptoms and duration of untreated psychosis (DUP). Bilirubin levels were reduced in 39 individuals with FEP compared with 20 HC (median [IQR]: 11.0 [9.0–13.0] µM vs. 15.0 [11.5–18.5] µM). In individuals with FEP, bilirubin levels were also positively correlated to two working memory tests (r = 0.40 and r = 0.32) and inversely correlated to DUP (r = − 0.36). Findings were not influenced by confounding factors. The results confirm the antioxidant deficit previously seen in schizophrenia, but also indicate that these changes may be related to DUP. The study also confirms that bilirubin may be implicated in the cognitive deficits that accompanies the disorder, here for the first time presented in individuals with FEP.

[Plasmatic glutathione levels and their relationships with clinical and therapeutic features in patients with schizophrenia]

INTRODUCTION

Altered glutathione systems (GSH) are suggested to participate in the pathophysiology of schizophrenia. The purpose of this study was to determine the plasmatic glutathione levels of patients with schizophrenia compared to healthy controls and to examine their relationships with clinical and therapeutic features.

METHODS

It was a case-control study carried out on 100 patients with schizophrenia according to DSM-IV-TR criteria and 95 healthy controls. All patients were assessed by Clinical Global Impressions-severity (CGI-severity) and Global Assessment of Functioning (EGF). Most of the patients (55%) were under first-generation antipsychotics. Plasmatic glutathione levels (total glutathione GSHt, reduced glutathione GSHr, oxidized glutathione GSSG) were determined by spectrophotometry.

RESULTS

The levels of GSHt and GSHr were significantly decreased in schizophrenic patients in comparison with the healthy controls. These reductions were noted to be more pronounced in the untreated patients. No correlation was observed between the GSH levels and the clinical subtypes of schizophrenia and EGF scores. Depending on the therapeutic status, there were no significant differences in the GSH levels. In addition, there was no correlation between the GSH levels and the daily dosage of the antipsychotic treatment.

CONCLUSION

Our results suggest that the observed changes are related to the physiopathology of schizophrenia rather than to the presence of neuroleptic treatment. These results provide support for further studies of the possible role of antioxidants as neuroprotective therapeutic strategies.

Diet and Psychosis: A Scoping Review

INTRODUCTION

Schizophrenia spectrum disorders (SSD) represent a cluster of severe mental illnesses. Diet has been identified as a modifiable risk factor and opportunity for intervention in many physical illnesses and more recently in mental illnesses such as unipolar depression; however, no dietary guidelines exist for patients with SSD.

OBJECTIVE

This review sought to systematically scope the existing literature in order to identify nutritional interventions for the prevention or treatment of mental health symptoms in SSD as well as gaps and opportunities for further research.

METHODS

This review followed established methodological approaches for scoping reviews including an extensive a priori search strategy and duplicate screening. Because of the large volume of results, an online program (Abstrackr) was used for screening and tagging. Data were extracted based on the dietary constituents and analyzed.

RESULTS

Of 55,330 results identified by the search, 822 studies met the criteria for inclusion. Observational evidence shows a connection between the presence of psychotic disorders and poorer quality dietary patterns, higher intake of refined carbohydrates and total fat, and lower intake or levels of fibre, ω-3 and ω-6 fatty acids, vegetables, fruit, and certain vitamins and minerals (vitamin B12 and B6, folate, vitamin C, zinc, and selenium). Evidence illustrates a role of food allergy and sensitivity as well as microbiome composition and specific phytonutrients (such as L-theanine, sulforaphane, and resveratrol). Experimental studies have demonstrated benefit using healthy diet patterns and specific vitamins and minerals (vitamin B12 and B6, folate, and zinc) and amino acids (serine, lysine, glycine, and tryptophan).

DISCUSSION

Overall, these findings were consistent with many other bodies of knowledge about healthy dietary patterns. Many limitations exist related to the design of the individual studies and the ability to extrapolate the results of studies using dietary supplements to dietary interventions (food). Dietary recommendations are presented as well as recommendations for further research including more prospective observational studies and intervention studies that modify diet constituents or entire dietary patterns with statistical power to detect mental health outcomes.

Dietary Behaviors and Metabolic Syndrome in Schizophrenia Patients

The metabolic syndrome (MS) is highly prevalent in schizophrenia patients, resulting from both pharmacotherapy and their lifestyle. To avoid its development, the analysis of patients' eating behaviors followed by the necessary nutritional changes should become a routine element of treatment. The aim of this study is to investigate the effect of dietary habits on the course of schizophrenia and MS, cognitive performance, symptom severity, and subjective assessment of eating behaviors in schizophrenia patients. Total of 87 participants (63.2% women) aged 19 to 67 years (M = 41.67; SD = 12.87), of whom 60 met the IDF criteria for MS, completed the PANSS, the verbal fluency test, the Stroop Color-Word Test, and the digit span task, followed by a thorough nutritional interview. There were no significant differences in the dietary behaviors between investigated schizophrenia patients with and without comorbid MS. Interestingly, their eating habits compared quite favorably to those described in the literature. No associations were found between positive eating habits and other tested variables in patients with MS. They were, however, linked to lower PANSS scores in the entire sample. In addition, positive eating habits correlated with better cognitive performance and a more adequate subjective assessment of dietary habits. It would be amiss to assume that schizophrenia patients lack the ability to control their eating behaviors. Nutrition education may foster desirable dietary changes and improve the sense of agency, thus helping to reduce symptom severity and enhancing cognitive performance in this patient population.

A five-year follow-up study of antioxidants, oxidative stress and polyunsaturated fatty acids in schizophrenia

OBJECTIVE

Oxidative stress and dysregulated antioxidant defence may be involved in the pathophysiology of schizophrenia. In the present study, we investigated changes in antioxidants and oxidative stress from an acute to a later stable phase. We hypothesised that the levels of oxidative markers are increased in schizophrenia compared with healthy controls; change from the acute to the stable phase; and are associated with the levels of membrane polyunsaturated fatty acids (PUFAs) and symptom severity.

METHODS

Fifty-five patients with schizophrenia spectrum disorders, assessed during an acute phase and 5 years later during a stable phase, and 51 healthy controls were included. We measured antioxidants (α-tocopherol, uric acid, albumin and bilirubin), markers of oxidative stress (F2-isoprostane and reactive oxygen metabolites) and membrane fatty acids. Antioxidants and oxidative stress markers were compared in schizophrenia versus healthy controls, adjusting for differences in sex, age and smoking, and changes over time. Associations between symptoms and PUFA were also investigated.

RESULTS

In the acute phase, α-tocopherol was significantly higher (p < 0.001), while albumin was lower (p < 0.001) compared with the stable phase. Changes in α-tocopherol were associated with PUFA levels in the acute phase. In the stable phase, schizophrenia patients had higher uric acid (p = 0.009) and lower bilirubin (p = 0.046) than healthy controls. CRP was higher in patients in the stable phase (p < 0.001), and there was no significant change from the acute phase.

CONCLUSION

The present findings of change in antioxidant levels in the acute versus stable phase of schizophrenia the present findings suggest that redox regulation is dynamic and changes during different phases of the disorder.

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

BACKGROUND

Severe mental illness (SMI) is thought to be associated with lower diet quality and adverse eating behaviours contributing towards physical health disparities. A rigorous review of the studies looking at dietary intake in psychotic disorders and bipolar disorder is lacking.AimsTo conduct a systematic, comprehensive evaluation of the published research on dietary intake in psychotic disorders and bipolar disorder.

METHOD

Six electronic databases were searched for studies reporting on dietary intakes in psychotic disorders and bipolar disorder. Dietary-assessment methods, and dietary intakes, were systematically reviewed. Where possible, data was pooled for meta-analysis and compared with healthy controls.

RESULTS

In total, 58 eligible studies were identified. People with SMI were found to have significantly higher dietary energy (mean difference 1332 kJ, 95% CI 487-2178 kJ/day, P = 0.002, g = 0.463) and sodium (mean difference 322 mg, 95% CI 174-490 mg, P < 0.001, g = 0.414) intake compared with controls. Qualitative synthesis suggested that higher energy and sodium intakes were associated with poorer diet quality and eating patterns.

CONCLUSIONS

These dietary components should be key targets for preventative interventions to improve weight and other physical health outcomes in people with SMI.Declaration of interestS.B.T. and E.T. have clinical dietitian appointments within the South Eastern Sydney Local Health District and do not receive any further funding.

Evidence for altered cell membrane lipid composition in postmortem prefrontal white matter in bipolar disorder and schizophrenia

Brain imaging suggests that white matter abnormalities, including compromised white matter integrity in the frontal lobe, are shared across bipolar disorder (BD) and schizophrenia (SCZ). However, the precise molecular and cellular correlates remain to be elucidated. Given evidence for widespread alterations in cell membrane lipid composition in both disorders, we sought to investigate whether lipid composition is disturbed in frontal white matter in SCZ and BD. The phospholipids phosphatidylethanolamine (PE) and phosphatidylcholine (PC) were quantified in white matter adjacent to the dorsolateral prefrontal cortex in subjects with BD (n = 34), SCZ (n = 35), and non-psychiatric controls (n = 35) using high-pressure liquid chromatography. Individual fatty acid species and plasmalogens were then quantified separately in PE and PC fractions by gas liquid chromatography. PC was significantly lower in the BD group, compared to controls. The fatty acids PE22:0, PE24:1 and PE20:2n6 were higher, and PC20:4n6, PE22:5n6 and PC22:5n6 lower in the BD group, relative to the control group. PE22:1 was higher and PC20:3n6, PE22:5n6 and PC22:5n6 lower in the SCZ group, compared to the control group. These data provide evidence for altered lipid composition in white matter in both BD and SCZ. Changes in white matter lipid composition could ultimately contribute to dysfunction of frontal white matter circuits in SCZ and BD.

Consensus paper of the WFSBP Task Force on Biological Markers: Criteria for biomarkers and endophenotypes of schizophrenia, part III: Molecular mechanisms

OBJECTIVES

Despite progress in identifying molecular pathophysiological processes in schizophrenia, valid biomarkers are lacking for both the disease and treatment response.

METHODS

This comprehensive review summarises recent efforts to identify molecular mechanisms on the level of protein and gene expression and epigenetics, including DNA methylation, histone modifications and micro RNA expression. Furthermore, it summarises recent findings of alterations in lipid mediators and highlights inflammatory processes. The potential that this research will identify biomarkers of schizophrenia is discussed.

RESULTS

Recent studies have not identified clear biomarkers for schizophrenia. Although several molecular pathways have emerged as potential candidates for future research, a complete understanding of these metabolic pathways is required to reveal better treatment modalities for this disabling condition.

CONCLUSIONS

Large longitudinal cohort studies are essential that pair a thorough phenotypic and clinical evaluation for example with gene expression and proteome analysis in blood at multiple time points. This approach might identify biomarkers that allow patients to be stratified according to treatment response and ideally also allow treatment response to be predicted. Improved knowledge of molecular pathways and epigenetic mechanisms, including their potential association with environmental influences, will facilitate the discovery of biomarkers that could ultimately be effective tools in clinical practice.

Omega – 3 fatty acids in schizophrenia – part I: importance in the pathophysiology of schizophrenia

Despite the increasing offer of antipsychotic drugs, the effectiveness of pharmacotherapy in schizophrenia is still unsatisfactory. Drug resistance, lack of complete remission and the increasing risk of metabolic complications are the reasons why the new forms of therapy in schizophrenia among which unsaturated essential fatty acids omega 3 (EFAs ω-3) affecting the proper functioning of nervous system, are mentioned, are being looked for.

Fatty acids represent 50-60% of the dry weight of the brain and diet is one of the factors that influence the value of each of the fat fractions in the neuron membranes. Patients with schizophrenia tend to have irregular nutritional status concerning essential fatty acids ω-3, which might result from metabolic disorders or irregular consumption of fatty acids.

Apart from being a review of the literature on this subject, this very paper characterizes essential fatty acids ω-3, their metabolism, the most important sources in the diet and the opinions of experts in the field about the recommended intake. It pays attention to the role of essential fatty acids in both the structure and functioning of the central nervous system is, as well as their role in the pathophysiology of schizophrenia, with particular emphasis on the membrane concept by David Horrobin. The assessment of the errors in consumption and metabolism of essential fatty acids are described as well.

The evidence was found both in epidemiological and modeling studies. It supports the participation of EFAs in etiopathogenesis and pathophysiology of schizophrenia. Further research is needed, both observational and interventional, as to the role of essential fatty acids ω-3 in the functioning of the CNS as well as the development and course of schizophrenia.

Levels of Red Blood Cell Fatty Acids in Patients With Psychosis, Their Unaffected Siblings, and Healthy Controls

BACKGROUND

Two recent meta-analyses showed decreased red blood cell (RBC) polyunsaturated fatty acids (FA) in schizophrenia and related disorders. However, both these meta-analyses report considerable heterogeneity, probably related to differences in patient samples between studies. Here, we investigated whether variations in RBC FA are associated with psychosis, and thus may be an intermediate phenotype of the disorder.

METHODS

For the present study, a total of 215 patients (87% outpatients), 187 siblings, and 98 controls were investigated for multiple FA analyses. Based on previous studies, we investigated docosahexaenoic acid (DHA), docosapentaenoic acid (DPA), arachidonic acid (AA), linoleic acid (LA), nervonic acid (NA), and eicasopentaenoic acid (EPA). On an exploratory basis, a large number of additional FA were investigated. Multilevel mixed models were used to compare the FA between the 3 groups.

RESULTS

Compared to controls, both patients and siblings showed significantly increased DHA, DPA, AA, and NA. LA was significantly higher in siblings compared to controls. EPA was not significantly different between the 3 groups. Also the exploratory FA were increased in patients and siblings.

CONCLUSIONS

We found increased RBC FA DHA, DPA, AA, and NA in patients and siblings compared to controls. The direction of change is similar in both patients and siblings, which may suggest a shared environment and/or an intermediate phenotype. Differences between patient samples reflecting stage of disorder, dietary patterns, medication use, and drug abuse are possible modifiers of FA, contributing to the heterogeneity in findings concerning FA in schizophrenia patients.

Fatty acid and vitamin interventions in adults with schizophrenia: a systematic review of the current evidence

Current psychopharmacological approaches to reduce psychotic phenomenology in schizophrenia are associated with adverse effects including extrapyramidal and metabolic side effects. In view of the emerging data on nutritional supplementation interventions in schizophrenia which are not entirely consistent, we aimed to review existent studies focusing on fatty acid and vitamin interventions and summarise current evidence on such nutritional supplementations in schizophrenia. We searched the digital databases (ScienceDirect, Scopus, SpringerLINK, PubMed/Medline) for relevant studies pertaining to fatty acid and vitamin supplementation interventions in the management of psychotic symptoms in schizophrenia up to February 2015. Overall, there were more studies conducted on fatty acid over vitamin supplementations in patients with schizophrenia. There were more positive findings in support of fatty acid supplementation compared with vitamin supplementation in the context of specific intervention features (dose of nutrient supplementation, single versus combination nutritional interventions, specific antipsychotic), subject features (older age, long duration of illness, baseline polyunsaturated fatty acid levels) and clinical outcomes (improvements of psychotic symptoms and/or extrapyramidal side effects from antipsychotics). However, investigations of both supplementation modalities were limited by relatively small study sample sizes, short study duration, which precluded further segmentation of impact on more diverse patient subtypes and symptom profiles. Future studies may consider examining larger samples over a longer time period, recruiting younger subjects with shorter duration of illness, examination of different clinical features including specific cognitive domains, and use of single versus combination nutritional interventions.

Can exercise increase fitness and reduce weight in patients with schizophrenia and depression?

BACKGROUND

Psychiatric patients have a reduced life expectancy of 15-20 years compared with the general population. Most years of lost life are due to the excess mortality from somatic diseases. Sedentary lifestyle and medication is partly responsible for the high frequency of metabolic syndrome in this patient group and low levels of physical activity is associated with increased risk of cardiovascular disease, diabetes, and all-cause mortality. This study aimed to review trials allocating patients with either schizophrenia or depression to exercise interventions for effect on cardiovascular fitness, strength, and weight.

METHODS

We searched PubMed, Embase, and PsycINFO including randomized clinical trial allocating patients with either schizophrenia or depression to isolated exercise interventions.

RESULTS

We identified five trials including patients with schizophrenia (n = 94) and found little evidence that exercise could increase cardiovascular fitness or decrease weight. Nine exercise trials for patients with depression (n = 892) were identified increasing cardiovascular fitness by 11-30% and strength by 33-37%. No evidence in favor of exercise for weight reduction was found.

CONCLUSION

Based on the current evidence isolated exercise interventions are unlikely to improve cardiovascular fitness or induce weight loss in patients with schizophrenia. In patients with depression, exercise interventions are likely to induce clinically relevant short term effects, however, due to lack of reporting, little is known about the effect on weight reduction and cardiovascular fitness. Future exercise trials regarding patients with mental illness should preferably measure changes in cardiovascular strength, repetition maximum, and anthropometric outcomes. Ideally, participants should be assessed beyond the intervention to identify long lasting effects.

Metabolic syndrome in bipolar disorder and schizophrenia: dietary and lifestyle factors compared to the general population

OBJECTIVE

Since a poor diet is often cited as a contributor to metabolic syndrome for subjects diagnosed with bipolar disorder and schizophrenia, we sought to examine dietary intake, cigarette smoking, and physical activity in these populations and compare them with those for the general population.

METHODS

Individuals diagnosed with bipolar disorder (n = 116) and schizophrenia (n = 143) were assessed for dietary intake, lifestyle habits, and metabolic syndrome and compared to age-, gender-, and race-matched subjects from the National Health and Nutrition Examination Survey (NHANES) 1999-2000. Additionally, matched subgroups within the patient populations were compared to elicit any differences.

RESULTS

As expected, the metabolic syndrome rate was higher in the samples with bipolar disorder (33%) and schizophrenia (47%) compared to matched NHANES controls (17% and 11%, respectively), and not different between the patient groups. Surprisingly, both subjects with bipolar disorder and those with schizophrenia consumed fewer total calories, carbohydrates and fats, as well as more fiber (p < 0.03), compared to NHANES controls. No dietary or activity differences between patient participants with and without metabolic syndrome were found. Subjects with schizophrenia had significantly lower total and low-density cholesterol levels (p < 0.0001) compared to NHANES controls. Subjects with bipolar disorder smoked less (p = 0.001), exercised more (p = 0.004), and had lower body mass indexes (p = 0.009) compared to subjects with schizophrenia.

CONCLUSIONS

Counter to predictions, few dietary differences could be discerned between schizophrenia, bipolar disorder, and NHANES control groups. The subjects with bipolar disorder exhibited healthier behaviors than the patients with schizophrenia. Additional research regarding metabolic syndrome mechanisms, focusing on non-dietary contributions, is needed.

Lipidomics reveals early metabolic changes in subjects with schizophrenia: effects of atypical antipsychotics

There is a critical need for mapping early metabolic changes in schizophrenia to capture failures in regulation of biochemical pathways and networks. This information could provide valuable insights about disease mechanisms, trajectory of disease progression, and diagnostic biomarkers. We used a lipidomics platform to measure individual lipid species in 20 drug-naïve patients with a first episode of schizophrenia (FE group), 20 patients with chronic schizophrenia that had not adhered to prescribed medications (RE group), and 29 race-matched control subjects without schizophrenia. Lipid metabolic profiles were evaluated and compared between study groups and within groups before and after treatment with atypical antipsychotics, risperidone and aripiprazole. Finally, we mapped lipid profiles to n3 and n6 fatty acid synthesis pathways to elucidate which enzymes might be affected by disease and treatment. Compared to controls, the FE group showed significant down-regulation of several n3 polyunsaturated fatty acids (PUFAs), including 20:5n3, 22:5n3, and 22:6n3 within the phosphatidylcholine and phosphatidylethanolamine lipid classes. Differences between FE and controls were only observed in the n3 class PUFAs; no differences where noted in n6 class PUFAs. The RE group was not significantly different from controls, although some compositional differences within PUFAs were noted. Drug treatment was able to correct the aberrant PUFA levels noted in FE patients, but changes in re patients were not corrective. Treatment caused increases in both n3 and n6 class lipids. These results supported the hypothesis that phospholipid n3 fatty acid deficits are present early in the course of schizophrenia and tend not to persist throughout its course. These changes in lipid metabolism could indicate a metabolic vulnerability in patients with schizophrenia that occurs early in development of the disease.

Red blood cell polyunsaturated fatty acids measured in red blood cells and schizophrenia: a meta-analysis

Alterations of polyunsaturated fatty acids (PUFA) in schizophrenia have been reported, but there is substantial variation in the findings. We performed a systematic review and meta-analysis for docosapentaenoic acid (DPA), docosahexaenoic acid (DHA), linoleic acid (LA), and arachidonic acid (AA). We identified 18 studies which compared PUFA in the erythrocyte cell membrane between patients with schizophrenia and controls. A total of 642 patients (169 were antipsychotic-naïve) and 574 controls participated in these studies. We found suggestive evidence that the levels of DPA (C22:5n3) and DHA (C22:6n3) are decreased both in patients currently being treated with antipsychotic medication and antipsychotic-naïve patients. Our findings furthermore suggest that the levels of LA (C18:2n6) are decreased in the medicated subgroup, but not in the antipsychotic-naive group. Finally, we found decreased levels of AA (C20:4n6), most convincingly in antipsychotic-naive patients. Taken together, there is substantial evidence that decreased levels of DPA (C22:5n3), DHA (C22:6n3), and AA (C20:4n6) are associated with the schizophrenia syndrome, apart from a possible influence of antipsychotic medication. Given the large heterogeneity in results, these conclusions should be interpreted cautiously.

Altered fatty acid concentrations in prefrontal cortex of schizophrenic patients

BACKGROUND

Disturbances in prefrontal cortex phospholipid and fatty acid composition have been reported in patients with schizophrenia (SCZ), often as an incomplete lipid profile or a percent of total lipid concentration. In this study, we quantified absolute concentrations (nmol/g wet weight) and fractional concentrations (i.e. percent of total fatty acids) of several lipid classes and their constituent fatty acids in postmortem prefrontal cortex of SCZ patients (n = 10) and age-matched controls (n = 10).

METHODS

Lipids were extracted, fractionated with thin layer chromatography and assayed.

RESULTS

Mean total lipid, phospholipid, individual phospholipids, plasmalogen, triglyceride and cholesteryl ester concentrations did not differ significantly between the groups. Compared to controls, SCZ brains showed significant increases in several monounsaturated and polyunsaturated fatty acid absolute concentrations in cholesteryl ester. Significant increases or decreases occurred in palmitoleic, linoleic, γ-linolenic and n-3 docosapentaenoic acid absolute concentrations in total lipids, triglycerides or phospholipids. Changes in fractional concentrations did not consistently reflect absolute concentration changes.

CONCLUSION

These findings suggest disturbed prefrontal cortex fatty acid absolute concentrations, particularly within cholesteryl esters, as a pathological aspect of schizophrenia.

No evidence of exogenous origin for the abnormal glutathione redox state in schizophrenia

Schizophrenia has been associated with low glutathione (GSH), one of the most important substrates for natural defense against oxidative stress. This abnormality is often attributed to genetic or other pathological causes. However, low GSH in schizophrenia could also be due to insufficient antioxidant consumption or other exogenous factors. We evaluated GSH in relation to diet, smoking, and medication status in schizophrenia patients. We recruited 54 participants (29 schizophrenia patients and 25 normal controls). The Antioxidant Dietary Source Questions was used to estimate the total antioxidant capacity (TAC) from participants' diet. GSH and the oxidized form of glutathione (GSSG) were assayed. We found that GSH was significantly lower (p<0.001) while %GSSG was 2 to 5 fold higher (p = 0.023) in patients compared with controls. No evidence for lower TAC dietary intake was found in schizophrenia patients compared with controls; rather nominally higher TAC level was found in the patients diet (p = 0.02). Analysis of consumption of individual food categories also failed to find evidence of reduced dietary antioxidant intake in schizophrenia patients. Smoking and medications did not significantly predict the GSH deficit either. However, there was a significant smoking by diagnosis interaction on GSH (p = 0.026) such that smoking was associated with higher GSH level in controls while smoking in patients was not associated with this effect. Schizophrenia patients may have an impaired upregulation of GSH synthesis that normally occurs due to smoking-induced antioxidative response. Lower GSH was independently present in patients on clozapine (p = 0.005) and patients on other antipsychotics (p<0.001) compared with controls. In conclusion, none of the exogenous sources played a major role in explaining abnormalities in the glutathione pathway in patients. The state of abnormal glutathione redox may therefore be a part of schizophrenia pathophysiology.

The dietary pattern of patients with schizophrenia: a systematic review

OBJECTIVE

People with schizophrenia show a high incidence of metabolic syndrome, which is associated with a high mortality from cardiovascular disease. The aetiology of the metabolic syndrome in schizophrenia is multi-factorial and may involve antipsychotic treatment, high levels of stress and unhealthy lifestyle, such as poor diet. As a poor diet can predispose to the development of metabolic abnormalities, the aims of this review are to clarify: 1) the dietary patterns of patients with schizophrenia, 2) the association of these dietary patterns with a worse metabolic profile, and 3) the possible factors influencing these dietary patterns.

METHODS

A search was conducted on Pubmed, The Cochrane Library, Scopus, Embase, Ovid, Psychoinfo and ISI web of Knowledge from 1950 to the 1st of November 2011. 783 articles were found through the investigation of such databases. After title, abstract or full-text reading and applying exclusion criteria we reviewed 31 studies on dietary patterns and their effects on metabolic parameters in schizophrenia.

RESULTS

Patients with schizophrenia have a poor diet, mainly characterized by a high intake of saturated fat and a low consumption of fibre and fruit. Such diet is more likely to increase the risk to develop metabolic abnormalities. Data about possible causes of poor diet in schizophrenia are still few and inconsistent.

CONCLUSION

Subjects with schizophrenia show a poor diet that partly accounts for their higher incidence of metabolic abnormalities. Further studies are needed to clarify the causes of poor diet and the role of dietary intervention to improve their physical health.

Olanzapine and risperidone effects on appetite and ghrelin in chronic schizophrenic patients

Olanzapine and other second generation antipsychotics have been associated with weight gain, which may be related to changes in appetite and food intake. However, it is unclear whether changes in appetite in response to treatment with second generation antipsychotics are persistent in patients treated chronically with these medications and the extent to which changes in appetite are related to any continuing weight gain associated with long-term treatment with these drugs. In a randomized 5-month study of the effects of olanzapine and risperidone on metabolic changes in chronic schizophrenic patients, we assessed appetite changes using two scales and correlated appetite changes with weight gain and metabolic changes. There is evidence that the hormone ghrelin is related to appetite stimulation and falls during satiation after meals, and therefore, may be a physiological concomitant indicating appetite changes. We therefore, also measured ghrelin before and after a fatty meal at baseline and after 2 months of drug treatment. Neither olanzapine nor risperidone increased appetite during the 5 months of study drug treatment, and there was a trend for a decrease in appetite over time. Weight only increased slightly during treatment and changes in appetite scores were not correlated with changes in weight or changes in glucose or lipids. Fasting ghrelin did not increase in olanzapine- or risperidone-treated patients, and there were no significant changes in ghrelin responses to a fatty meal between baseline and 2 months of drug treatment, and no differences in response in olanzapine- vs. risperidone-treated patients. Our findings suggest that in chronic schizophrenic patients treated with multiple antipsychotics in the past, olanzapine or risperidone do not induce increases in appetite and appetite changes are not related to any further small drug-induced weight gain in these chronically treated patients. However, it is possible that different relationships may exist between appetite and weight changes induced by the medications in drug naive patients newly started on olanzapine or risperidone.

Reduced serum non-enzymatic antioxidant defense and increased lipid peroxidation in schizophrenic patients on a hypocaloric diet

INTRODUCTION

Growing evidence suggests that oxidative stress (OS) may be associated with the pathophysiology underlying schizophrenia (SZ). Some studies indicate that nutritional supplements offer protection from OS, but there is no data about the effect of a hypocaloric diet on OS in this population. Therefore, we aimed to study the effect of a hypocaloric dietary intervention on OS in subjects with SZ.

METHODS

A cross-sectional study of 96 participants in outpatient treatment for SZ comprised patients separated into two groups: one group of subjects followed a hypocaloric diet (HD) program (n=42), while the other group followed a regular diet (RD) with no nutritional restrictions (n=54). The serum total radical-trapping antioxidant parameter (TRAP), total antioxidant reactivity (TAR) and thiobarbituric acid reactive species (TBARS) levels were assessed.

RESULTS

TRAP levels were lower and TBARS levels were higher in the HD group than in the RD group (p=0.022 and p=0.023, respectively). There were no differences in TAR levels between the groups. Additionally, there was a positive correlation between TRAP and TBARS levels after adjusting for BMI and clozapine dose (partial correlation=0.42, p<0.001). There were no correlations among the length of illness or diet and the levels of TRAP, TBARS, and TAR.

CONCLUSIONS

Subjects with SZ on a hypocaloric diet displayed different OS parameters than those not following a HD. Serum TRAP levels were lower and TBARS levels were higher among SZ subjects with HD compared to SZ subjects without HD. Lower TRAP levels may reflect decreased oxidative stress, whereas higher TBARS levels most likely reflect a biochemical reaction to the decreased TRAP levels. Additionally, TAR levels were similar between groups, suggesting a similar quality of antioxidant defenses, despite quantitative differences between the two dietary protocols in SZ patients under outpatient care.

Cognitive deficits, obesity and disability in schizophrenia

Despite 50 years of pharmacological and psychosocial interventions schizophrenia remains one of the leading causes of disability. The inability to function in everyday settings includes deficits in performance of social, occupational, and independent living activities. Schizophrenia is also a life-shortening illness, caused mainly by poor physical health and its complications. Dysfunctional lifestyles including sedentary behavior and lack of physical activity prevail, while treatment with adipogenic antipsychotic medication interacts with poor performance in screening, monitoring, and intervention that result in shortening of life expectancies by 25–30 years. Disability interferes with self-care and medical care, further worsening physical health to produce a vicious cycle of disability. Further, the neurobiological impact of obesity on brain functioning is substantial and relevant to schizophrenia. Decision making deficits that lead to choices resulting in obesity themselves have neurobiological determinants. Simultaneous treatment of cognitive deficits and related deficits in functional skills, ubiquitous determinants of everyday functioning in schizophrenia, and targeted interventions aimed at poor physical health, especially obesity and associated comorbidities, may lead to additive or even interactive gains in everyday functioning in patients with schizophrenia not previously realized with other interventions.

Bimodal distribution of polyunsaturated fatty acids in schizophrenia suggests two endophenotypes of the disorder

BACKGROUND

There is conflicting evidence of whether polyunsaturated fatty acids (PUFA) in red blood cells are bimodally distributed in schizophrenia. The purpose of this study was to examine the distribution of PUFA, as well as its links to plausible causal factors.

METHODS

A 16-week cohort study and a case-control study as part of a randomized controlled trial. Ninety-nine patients with DSM-IV schizophrenia, schizoaffective disorder, or schizophreniform disorder, aged 18 to 39, were consecutively included at admission to psychiatric departments of nine Norwegian hospitals. Fatty acids were measured in 97 of these patients and in 20 healthy control subjects. The primary outcome measure was the bimodality test statistic T, assessed by a χ(2) test of the likelihood of one or two normal distributions of PUFA.

RESULTS

At baseline, levels of polyunsaturated fatty acids were highly significantly bimodally distributed among patients. One third of patients constituted a group (low PUFA) who had PUFA levels at one fifth (p < .001) of those in high PUFA patients and healthy control subjects, which did not differ. Bimodality was mainly accounted for by docosahexaenoic acid and arachidonic acid. Bimodality was confirmed after 16 weeks. α-tocopherol was a robust predictor of PUFA at both occasions. Desaturase and elongase indexes differed between PUFA groups. Smoking, gender, antipsychotic medication, and dietary factors did not explain the bimodal distribution.

CONCLUSIONS

Red blood cell PUFA were bimodally distributed among acutely ill patients with schizophrenia and schizoaffective disorder. Endogenous deficiencies of redox regulation or synthesis of long-chain PUFA in the low PUFA group may explain our findings.

Oxidative stress in schizophrenia

Increasing evidence indicates that oxidative damage exists in schizophrenia. Available literature about possible mechanisms of oxidative stress induction was reviewed. Furthermore, possibilities of measuring biomarkers of schizophrenia outside the central nervous system compartment, their specificity for different types of schizophrenia and potential therapeutic strategies to prevent oxidative injuries in schizophrenia were discussed. Data were extracted from published literature found in Medline, Embase, Biosis, Cochrane and Web of Science, together with hand search of references. Search terms were: schizophrenia, oxidative stress, antipsychotics, antioxidants and fatty acids. Finding a sensitive, specific and non invasive biomarker of schizophrenia, which could be measured in peripheral tissue, still stays an important task. Antioxidant enzymes, markers of lipid peroxidation, oxidatively modified proteins and DNA are most commonly used. As it considers the supplemental therapy, according to our meta-analysis vitamin E could potentially improve tardive dyskinesia, while for the effect of therapy with polyunsaturated fatty acids there is no clear evidence. Oxidative stress is a part of the pathology in schizophrenia and appears as a promising field to develop new therapeutic strategies. There is a need for well designed, placebo controlled trials with supplementation therapy in schizophrenia.

Increased breath ethane levels in medicated patients with schizophrenia and bipolar disorder are unrelated to erythrocyte omega-3 fatty acid abundance

Oxidative stress has been reported to be elevated in mental illness. Preliminary evidence suggests this phenomenon can be assessed non-invasively by determining breath levels of the omega-3 polyunsaturated fatty acid (PUFA) oxidation product ethane. This study compares alkane levels in chronic, medicated, patients with schizophrenia or bipolar disorder with those in healthy controls. Both ethane and butane levels were significantly increased in patients with schizophrenia or bipolar disorder, although elevated butane levels were likely due to increased ambient gas concentrations. Ethane levels were not correlated with symptom severity or with erythrocyte omega-3 PUFA levels. Our results support the hypothesis that oxidative stress is elevated in patients with schizophrenia and bipolar disorder leading to increased breath ethane abundance. This does not appear to be caused by increased abundance of omega-3 PUFA, but rather is likely due to enhanced oxidative damage of these lipids. As such, breath hydrocarbon analysis may represent a simple, non-invasive means to monitor the metabolic processes occurring in these disorders.

Elevated delta-6 desaturase (FADS2) expression in the postmortem prefrontal cortex of schizophrenic patients: relationship with fatty acid composition

Although emerging evidence suggests that schizophrenia (SZ) is associated with peripheral and central polyunsaturated fatty acid (PUFA) deficits, there is currently nothing known about the expression of genes that mediate PUFA biosynthesis in SZ patients. Here we determined Delta5 desaturase (FADS1), Delta6 desaturase (FADS2), elongase (HELO1 [ELOVL5]), peroxisomal (PEX19), and Delta9 desaturase (stearoyl-CoA desaturase, SCD) mRNA expression, and relevant fatty acid product:precursor ratios as estimates of enzyme activities, in the postmortem prefrontal cortex (PFC) of patients with SZ (n=20) and non-psychiatric controls (n=20). After correction for multiple comparisons, FADS2 mRNA expression was significantly greater in SZ patients relative to controls (+36%, p=0.002), and there was a positive trend found for FADS1 (+26%, p=0.15). No differences were found for HELO1 (+10%, p=0.44), PEX19 (+12%, p=0.44), or SCD (-6%, p=0.85). Both male (+34%, p=0.02) and female (+42%, p=0.02) SZ patients exhibited greater FADS2 mRNA expression relative to same-gender controls. Drug-free SZ patients (+37%, p=0.02), and SZ patients treated with typical (+40%, p=0.002) or atypical (+31%, p=0.04) antipsychotics, exhibited greater FADS2 mRNA expression relative to controls. Consistent with increased Delta6 desaturase activity, SZ patients exhibited a greater 20:3/18:2 ratio (+20%, p=0.03) and a positive trend was found for 20:4/18:2 (+13%, p=0.07). These data demonstrate abnormal, potentially compensatory, elevations in Delta6 desaturase (FADS2) expression in the PFC of SZ patients that are independent of gender and antipsychotic medications. Greater Delta6 desaturase expression and activity could have implications for central prostaglandin synthesis and proinflammatory signaling.

Is there a role for n-3 long-chain polyunsaturated fatty acids in the regulation of mood and behaviour? A review of the evidence to date from epidemiological studies, clinical studies and intervention trials

Selected biochemical evidence suggests a potential role for n-3 long-chain PUFA (n-3PUFA) in the regulation of mood and behaviour. The present paper reviews the relevant evidence, to date, from epidemiological studies, clinical studies and intervention trials. Most evidence is available investigating a role for n-3PUFA in depression, depressive illness and suicidal behaviour, but work is also available on anxiety and anxiety-related disorders, fatigue and fatigue-related disorders, aggression, hostility and anti-social behaviour, inattention, impulsivity and attention deficit hyperactivity disorder and schizophrenic disorders. For all these aspects of mood and behaviour, the evidence available is currently limited and highly inconsistent, both in terms of study methodology and study findings. There is a clear need for further work in this area.

Chronic risperidone treatment preferentially increases rat erythrocyte and prefrontal cortex omega-3 fatty acid composition: evidence for augmented biosynthesis

Prior clinical studies suggest that chronic treatment with atypical antipsychotic medications increase erythrocyte and postmortem prefrontal cortex (PFC) omega-3 fatty acid composition in patients with schizophrenia (SZ). However, because human tissue phospholipid omega-3 fatty acid composition is potentially influenced by multiple extraneous variables, definitive evaluation of this putative mechanism of action requires an animal model. In the present study, we determined the effects of chronic treatment with the atypical antipsychotic risperidone (RISP, 3.0 mg/kg/d) on erythrocyte and PFC omega-3 fatty acid composition in rats maintained on a diet with or without the dietary omega-3 fatty acid precursor, alpha-linolenic acid (ALA, 18:3n-3). Chronic RISP treatment resulted in therapeutically-relevant plasma RISP and 9-OH-RISP concentrations (18+/-2.6 ng/ml), and significantly increased erythrocyte docosahexaenoic acid (DHA, 22:6n-3, +22%, p=0.0003) and docosapentaenoic acid (22:5n-3, +18%, p=0.01) composition, and increased PFC DHA composition (+7%, p=0.03) in rats maintained on the ALA+ diet. In contrast, chronic RISP did not alter erythrocyte or PFC omega-3 fatty acid composition in rats maintained on the ALA- diet. Chronic RISP treatment did not alter erythrocyte or PFC arachidonic acid (AA, 20:4n-6) composition. These data suggest that chronic RISP treatment significantly augments ALA-DHA biosynthesis, and preferentially increases peripheral and central membrane omega-3 fatty acid composition. Augmented omega-3 fatty acid biosynthesis and membrane composition represents a novel mechanism of action that may contribute in part to the efficacy of RISP in the treatment of SZ.

Is dietary pattern of schizophrenia patients different from healthy subjects?

BACKGROUND

There are limited findings about dietary patterns and food preferences among patients suffering from schizophrenia. The main objective of this study was therefore to compare the nutritional pattern of schizophrenia patients with that of matched healthy subjects.

METHODS

The dietary pattern of 30 hospitalized 16-67 years old schizophrenic patients (11 female) was compared with that of 30 healthy age and sex matched individuals as control group. Subjects' anthropometric measurements including weight, height and body mass index (BMI), semi-quantitative food frequency (FFQ), medical and food history questionnaires were also collected and FFQs were then scored using Food Guide Pyramid to obtain the dietary scores. Percent body fat (%BF) was measured using bioelectrical impedance analysis (BIA) method.

RESULTS

Female patients had more %BF and lower dietary pattern scores than that of their controls (32 +/- 3.6 vs 27.7 +/- 4.6 percent and 43.2 +/- 11.9 vs 54.5 +/- 10.7 points; respectively, p < 0.05 for both). They also consumed less milk and dairy products, fresh vegetables, fruits, chicken, and nuts compared with the female controls (p < 0.03). However, these patients used to eat more full-fat cream and carbonated drinks (p < 0.05). Male patients had lower BMI (22 +/- 4.7 vs 25.6 +/- 4.4; p < 0.05) than their counterpart controls but there was no significant difference between their %BFs. Moreover, they used to have more full-fat cream, hydrogenated fats, less red meat and nuts compared with the male controls (p < 0.05).

CONCLUSION

Schizophrenia patients have poor nutritional patterns. In particular, female patients have more percent body fat and lower dietary pattern scores compared with their healthy controls. All patients used to consume more fats and sweet drinks frequently. The findings of this study suggest that schizophrenia patients need specific medical nutrition therapies through limiting dietary fats and sugars intakes and weight control. Whether obesity is the consequence of disease, dietary preference or medications used remains to be cleared.

Assessment of malondialdehyde levels in schizophrenia: a meta-analysis and some methodological considerations

Oxidative stress has long been suggested to participate in the pathophysiology of schizophrenia. Most of the published data on the subject rely on malondialdehyde levels assessment through thiobarbituric acid reactive substances (TBARS), despite significant methodological concerns. The present paper reports on a meta-analysis of studies published up to July 2006. Relevant studies were identified through PubMed search and the References section of experimental and review papers on the subject. Studies were retained for analysis if they provided adequate methods description, controls and subjects numbers, means and standard deviations. Using a random effect model, an effect size of 1.22 (CI: 0.64-1.80) was found, with significant bias and high heterogeneity. Inspection of the bias assessment plot suggested a lower value in the order of d approximately 0.5, in line with the results of the larger studies. The heterogeneity of the results appeared to be unrelated to assay type or biological sample. However a meta-regression analysis suggested an association, at trend level, between the precision-weighted effect size and the proportion of drug-free patients, which might therefore account for some of the heterogeneity.

Food intake and reward mechanisms in patients with schizophrenia: implications for metabolic disturbances and treatment with second-generation antipsychotic agents

Obesity is highly prevalent among patients with schizophrenia and is associated with detrimental health consequences. Although excessive consumption of fast food and pharmacotherapy with such second-generation antipsychotic agents (SGAs) as clozapine and olanzapine has been implicated in the schizophrenia/obesity comorbidity, the pathophysiology of this link remains unclear. Here, we propose a mechanism based on brain reward function, a relevant etiologic factor in both schizophrenia and overeating. A comprehensive literature search on neurobiology of schizophrenia and of eating behavior was performed. The collected articles were critically reviewed and relevant data were extracted and summarized within four key areas: (1) energy homeostasis, (2) food reward and hedonics, (3) reward function in schizophrenia, and (4) metabolic effects of the SGAs. A mesolimbic hyperdopaminergic state may render motivational/incentive reward system insensitive to low salience/palatability food. This, together with poor cognitive control from hypofunctional prefrontal cortex and enhanced hedonic impact of food, owing to exaggerated opioidergic drive (clinically manifested as pain insensitivity), may underlie unhealthy eating habits in patients with schizophrenia. Treatment with SGAs purportedly improves dopamine-mediated reward aspects, but at the cost of increased appetite and worsened or at least not improved opiodergic capacity. These effects can further deteriorate eating patterns. Pathophysiological and therapeutic implications of these insights need further validation via prospective clinical trials and neuroimaging studies.

Increased caffeine and nicotine consumption in community-dwelling patients with schizophrenia

INTRODUCTION

It is known that people with schizophrenia make poor dietary choices and smoke at alarmingly high rates. There is also anecdotal evidence that they may ingest large amounts of caffeine. However, while smoking habits in this population have been examined, no recent study has quantified caffeine consumption taking into account various dietary caffeine sources unrelated to coffee including convenience foods such as candy bars, chocolate or soft drinks, and compared results to US population data.

METHODS

We employed 24-h diet recalls to assess dietary habits in a sample of outpatients suffering from schizophrenia or schizoaffective disorder. Caloric intake and caffeine consumption were quantified and the relationship to various sociodemographic variables including body mass index (BMI) and dietary quality was examined.

RESULTS

146 patients were recruited. Mean BMI in the sample was 32.7+/-7.9. Patients ingested 3,057+/-1,132 cal on average. Patients smoked at higher rates (59.6% vs. 23.4%, p< or =0.001), higher numbers of cigarettes/day (24+/-14.4 vs. 13.5+/-11.3, t=8.549, p<0.001) and ingested more caffeine (471.6+/-584.6 mg vs. 254.2+/-384.9 mg, t=6.664, p<0.001) than US population comparisons. Caffeine consumption was correlated to the number of cigarettes smoked daily (r=0.299, p< or =0.001), but not to BMI (r=0.134, p=0.107) or dietary parameters such as caloric intake (r=0.105, p=0.207).

CONCLUSION

Community-dwelling schizophrenia patients consume significantly more caffeine and nicotine than US population comparisons. Clinicians should be aware that while a significant proportion of patients are overweight and have poor dietary quality - which merits lifestyle counseling on its own - there is a lack of correlation between those factors and smoking and caffeine intake. Thus, lifestyle modification counseling in all patients should address smoking and caffeine intake concurrently.

The role of phospholipases A2 in schizophrenia

A range of neurotransmitter systems have been implicated in the pathogenesis of schizophrenia based on the antidopaminergic activities of antipsychotic medications, and chemicals that can induce psychotic-like symptoms, such as ketamine or PCP. Such neurotransmitter systems often mediate their cellular response via G-protein-coupled release of arachidonic acid (AA) via the activation of phospholipases A2 (PLA2s). The interaction of three PLA2s are important for the regulation of the release of AA--phospholipase A2 Group 2 A, phospholipase A2 Group 4A and phospholipase A2 Group 6A. Gene variations of these three key enzymes have been associated with schizophrenia with conflicting results. Preclinical data suggest that the activity of these three enzymes are associated with monoaminergic neurotransmission, and may contribute to the differential efficacy of antipsychotic medications, as well as other biological changes thought to underlie schizophrenia, such as altered neurodevelopment and synaptic remodelling. We review the evidence and discuss the potential roles of these three key enzymes for schizophrenia with particular emphasis on published association studies.

Common genetic variants of the FADS1 FADS2 gene cluster and their reconstructed haplotypes are associated with the fatty acid composition in phospholipids

Fatty acid composition in membranes plays an important role in cellular processes and has shown to be associated with the aetiology of several complex diseases in humans. We report strong associations between variants in the human delta-5 and delta-6 desaturase genes FADS1 FADS2 and fatty acid composition in serum phospholipids. Eighteen polymorphisms located in this gene cluster were genotyped in 727 adults from Erfurt, a German centre of the European Community Respiratory Health Survey. The cluster is located at chromosome 11q12-11q13.1, a region repeatedly found to be linked with atopy and other complex diseases. Polymorphisms and statistically reconstructed haplotypes of FADS1 and the upstream region of FADS2 showed strongest associations with the level of the direct precursor of inflammatory eicosanoids, the n-6 fatty acid arachidonic acid (C20:4n-6), also strong associations with levels of the n-6 fatty acids C18:2n-6, C18:3n-6, C20:2n-6, C20:3n-6, C22:4n-6 and of the n-3 fatty acids C18:3n-3, C20:5n-3 and C22:5n-3 (P-values < 1.0 x 10(-13)). Carriers of the rare alleles of several SNPs and their respective haplotypes had a lower prevalence of allergic rhinitis and atopic eczema. No association was found for total and specific IgE levels.

Low essential fatty acid and B-vitamin status in a subgroup of patients with schizophrenia and its response to dietary supplementation

We assessed essential fatty acid (EFA) and B-vitamin status, together with their determinants, in 61 patients with schizophrenia and established whether those with poor status responded biochemically to the appropriate dietary supplements. As a group, the patients had high erythrocyte saturated fatty acids (FAs), monounsaturated FA and low polyunsaturated FA of the omega3 and omega6 series. Patients reporting not to take vitamin supplements had low vitamin B12 and high homocysteine. Homocysteine variance proved best explained by folate in both the total group and male patients, and by vitamins B12 and B6 in females. Alcohol consumption and duration of illness are risk factors for low polyunsaturated FA status (< P2.5 of reference range), while male gender and absence of fish consumption predict hyperhomocysteinemia (> P97.5 of reference range). Two patients exhibited biochemical EFA deficiency and seven showed biochemical signs of omega3/docosahexaenoic acid (DHA) marginality. Four patients exhibited moderate hyperhomocysteinemia with plasma values ranging from 57.5 to 74.8 micromol/L. None of the five patients with either moderate hyperhomocysteinemia, biochemical EFA deficiency, or both, was predicted by their clinicians to have poor diets. That diet was nevertheless at the basis of these abnormalities became confirmed after supplementing 4 of them with B vitamins and with soybean and fish oils. We conclude that a subgroup of patients with schizophrenia has biochemical EFA deficiency, omega3/DHA marginality, moderate hyperhomocysteinemia, or combinations. Correction seems indicated in view of the possible relation of poor EFA and B-vitamin status with some of their psychiatric symptoms, but notably to reduce their high risk of cardiovascular disease.