Mediterranean diet, stroke, cognitive impairment, and depression: A meta-analysis

A review of nutrient treatments for paediatric depression

Paediatric depression is estimated to affect 15-20% of youths prior to adulthood and is associated with significant social, educational and physical impairment. Current treatments comprise moderately efficacious psychological therapies and pharmaceutical antidepressants. However, nutritional therapies are also available and are regularly sought by people with depressive illnesses and parents of depressed youths. In this narrative review, studies examining the antidepressant effects of individual nutritional supplements in child and adolescent populations are appraised. Epidemiological studies examining the relationship between nutritional status and paediatric depression, or depressive symptoms are also reviewed. Nutrients covered in this article include: omega-3 polyunsaturated fatty acids, s-adenosylmethionine, vitamin C, vitamin D, zinc, iron and B-vitamins. Although several of these nutrients present as promising treatments for paediatric depression, there is a lack of high-quality studies examining the antidepressant effects of all the aforementioned ingredients. Before nutritional treatments are accepted as validated treatments for paediatric depression, further high-quality studies are required.

Apolipoprotein E ε-4 as a genetic determinant of Alzheimer's disease heterogeneity

Alzheimer's disease (AD) displays a high degree of heterogeneity in terms of its etiology, presentation, prognosis, and treatment response. This can partly be explained by high-penetrance mutations in the amyloid precursor protein, presenilin 1 and presenilin 2 genes causing amyloid beta aggregation, which is a major pathogenic mechanism in the development of early-onset AD in a small subgroup of patients. Late-onset AD is considered a polygenic disorder in which cumulative risk resulting from interaction with modifiable environmental risk factors may be responsible for the majority of cases. The ε-4 allele of the apolipoprotein E (APOE) gene has emerged as the most significant genetic risk factor for late-onset AD, influencing nearly every pathogenic domain affected in AD. It is a major risk factor for cerebral amyloid angiopathy, recognized as a common pathological finding in an AD subtype associated with white matter dysfunction. The APOE ε-4 allele is also a known risk factor for ischemic stroke, which can result in vascular dementia or contribute to subcortical vascular dysfunction. In this review, we evaluate the clinical relevance of APOE genotyping in relation to cholesterol metabolism and available evidence on risk reduction strategies applicable to AD.

Impacts of in utero and early infant taste experiences on later taste acceptance: a systematic review

BACKGROUND

Dietary behavior exerts a critical influence on health and is the outcome of a broad range of interacting factors, including food and taste acceptance. These may be programmed in utero and during early infancy.

OBJECTIVE

We examined the hypothesis that fetuses and infants exposed to sweet, salty, sour, bitter, umami, or specific tastes show greater acceptance of that same taste later in life.

METHODS

We conducted a systematic review of the literature, using comprehensive searches and following established procedures for screening, data extraction, and quality appraisal. We used harvest plots to synthesize the evidence graphically.

RESULTS

Twenty studies comprising 38 subgroups that differed by taste, age, medium, and duration of exposure were included. Exposure to bitter and specific tastes increased the acceptance of these tastes. Studies on sweet and salty tastes showed equivocal results. Studies on sour tastes were sparse.

CONCLUSION

Our systematic review clearly shows programming of the acceptance of bitter and specific tastes. For other tastes the results were either equivocal or confined to a few number of studies that precluded us from drawing conclusions. Further research should examine the association of salty and sour taste exposures on later preferences of these tastes. Long-term studies and randomized clinical trials on each type of taste are needed.

Dysbiotic drift: mental health, environmental grey space, and microbiota

Advances in research concerning the mental health implications of dietary patterns and select nutrients have been remarkable. At the same time, there have been rapid increases in the understanding of the ways in which non-pathogenic microbes can potentially influence many aspects of human health, including those in the mental realm. Discussions of nutrition and microbiota are often overlapping. A separate, yet equally connected, avenue of research is that related to natural (for example, green space) and built environments, and in particular, how they are connected to human cognition and behaviors. It is argued here that in Western industrial nations a ‘disparity of microbiota’ might be expected among the socioeconomically disadvantaged, those whom face more profound environmental forces. Many of the environmental forces pushing against the vulnerable are at the neighborhood level. Matching the developing microbiome research with existing environmental justice research suggests that grey space may promote dysbiosis by default. In addition, the influence of Westernized lifestyle patterns, and the marketing forces that drive unhealthy behaviors in deprived communities, might allow dysbiosis to be the norm rather than the exception in those already at high risk of depression, subthreshold (subsyndromal) conditions, and subpar mental health. If microbiota are indeed at the intersection of nutrition, environmental health, and lifestyle medicine (as these avenues pertain to mental health), then perhaps the rapidly evolving gut-brain-microbiota conversation needs to operate through a wider lens. In contrast to the more narrowly defined psychobiotic, the term eco-psychotropic is introduced.

Healthy eating and reduced risk of cognitive decline: A cohort from 40 countries

OBJECTIVE

We sought to determine the association of dietary factors and risk of cognitive decline in a population at high risk of cardiovascular disease.

METHODS

Baseline dietary intake and measures of the Mini-Mental State Examination were recorded in 27,860 men and women who were enrolled in 2 international parallel trials of the ONTARGET (Ongoing Telmisartan Alone and in Combination with Ramipril Global Endpoint Trial) and TRANSCEND (Telmisartan Randomised Assessment Study in ACE Intolerant Subjects with Cardiovascular Disease) studies. We measured diet quality using the modified Alternative Healthy Eating Index. Cox proportional hazards regression was used to determine the association between diet quality and risk of ≥3-point decline in Mini-Mental State Examination score, and reported as hazard ratio with 95% confidence intervals with adjustment for covariates.

RESULTS

During 56 months of follow-up, 4,699 cases of cognitive decline occurred. We observed lower risk of cognitive decline among those in the healthiest dietary quintile of modified Alternative Healthy Eating Index compared with lowest quintile (hazard ratio 0.76, 95% confidence interval 0.66-0.86, Q5 vs Q1). Lower risk of cognitive decline was consistent regardless of baseline cognitive level.

CONCLUSION

We found that higher diet quality was associated with a reduced risk of cognitive decline. Improved diet quality represents an important potential target for reducing the global burden of cognitive decline.

Benefits of the Mediterranean Diet: Insights From the PREDIMED Study

The PREDIMED (PREvención con DIeta MEDiterránea) multicenter, randomized, primary prevention trial assessed the long-term effects of the Mediterranean diet (MeDiet) on clinical events of cardiovascular disease (CVD). We randomized 7447 men and women at high CVD risk into three diets: MeDiet supplemented with extra-virgin olive oil (EVOO), MeDiet supplemented with nuts, and control diet (advice on a low-fat diet). No energy restriction and no special intervention on physical activity were applied. We observed 288 CVD events (a composite of myocardial infarction, stroke or CVD death) during a median time of 4.8years; hazard ratios were 0.70 (95% CI, 0.53-0.91) for the MeDiet+EVOO and 0.70 (CI, 0.53-0.94) for the MeDiet+nuts compared to the control group. Respective hazard ratios for incident diabetes (273 cases) among 3541 non-diabetic participants were 0.60 (0.43-0.85) and 0.82 (0.61-1.10) for MeDiet+EVOO and MeDiet+nuts, respectively versus control. Significant improvements in classical and emerging CVD risk factors also supported a favorable effect of both MeDiets on blood pressure, insulin sensitivity, lipid profiles, lipoprotein particles, inflammation, oxidative stress, and carotid atherosclerosis. In nutrigenomic studies beneficial effects of the intervention with MedDiets showed interactions with several genetic variants (TCF7L2, APOA2, MLXIPL, LPL, FTO, M4CR, COX-2, GCKR and SERPINE1) with respect to intermediate and final phenotypes. Thus, the PREDIMED trial provided strong evidence that a vegetable-based MeDiet rich in unsaturated fat and polyphenols can be a sustainable and ideal model for CVD prevention.

Does reverse causality explain the relationship between diet and depression?

BACKGROUND

Observational studies have repeatedly demonstrated relationships between habitual diet quality and depression. However, whilst reverse causality has not been the identified mechanism for these associations in prospective studies, the relationship between diet and depression is likely complex and bidirectional. Thus explicit investigation of the reverse causality hypothesis is warranted.

METHODS

Data were drawn from the Personality and Total Health (PATH) Through Life Study, a longitudinal community survey following three age cohorts from Australia. Analyses evaluated the relationships between past depression and treatment, current depressive symptoms and dietary patterns.

RESULTS

Individuals with current depression had lower scores on a healthy dietary pattern; however, those who had been previously depressed and sought treatment had higher scores on the healthy dietary pattern at the later baseline assessment. Moreover, those who had reported prior, but not current, depression also had lower scores on the western dietary pattern than those without prior depression, regardless of whether they had been previously treated for their symptoms.

LIMITATIONS

Self-report data and possible recall bias limit our conclusions.

CONCLUSIONS

In this study, prior depression was associated with better quality diets at the later time point. Thus, while current depression is associated with poorer dietary habits, a history of depression may prompt healthier dietary behaviours in the long term. Given the demonstrated relationships between diet quality and depressive illness, clinicians should advocate dietary improvement for their patients with depression and should not be pessimistic about the likelihood of adherence to such recommendations.

Epigenetic impact of curcumin on stroke prevention

The epigenetic impact of curcumin in stroke and neurodegenerative disorders is curiosity-arousing. It is derived from Curcuma longa (spice), possesses anti-oxidative, anti-inflammatory, anti-lipidemic, neuro-protective and recently shown to exhibit epigenetic modulatory properties. Epigenetic studies include DNA methylation, histone modifications and RNA-based mechanisms which regulate gene expression without altering nucleotide sequences. Curcumin has been shown to affect cancer by altering epigenetic changes but its role as an epigenetic agent in cerebral stroke has not been much explored. Although curcumin possesses remarkable medicinal properties, the bioavailability of curcumin has limited its success in epigenetic studies and clinical trials. The present review is therefore designed to look into epigenetic mechanisms that could be induced with curcumin during stroke, along with its molecular designing with different moieties that may increase its bioavailability. Curcumin has been shown to be encapsulated in exosomes, nano-vesicles (<200 nm), thereby showing its therapeutic effects in brain diseases. Curcumin delivered through nanoparticles has been shown to be neuroregenerative but the use of nanoparticles in brain has limitations. Hence, curcumin-encapsulated exosomes along with curcumin-primed exosomes (exosomes released by curcumin-treated cells) are much needed to be explored to broadly look into their use as a novel therapy for stroke.

The association between diet quality and mental health during the perinatal period. A systematic review

BACKGROUND

While maternal nutrition during pregnancy is known to play a critical role in the health of both mother and offspring, the magnitude of this association has only recently been realized. Novel, epigenetic data suggest that maternal dietary intake has permanent phenotypic consequences for offspring, highlighting the potency of antenatal diet. To date, the relationship between poor antenatal diet and maternal mental health specifically, remains poorly understood. Therefore, we aimed to systematically review evidence that has examined associations between antenatal diet quality and the experience of depressive, anxiety and stress symptoms during the perinatal period.

METHODS

A search for peer-reviewed papers was conducted using Medline Complete, PsycINFO, CINAHL, Academic Search Premiere and Psychology and Behavioral Science Collection.

RESULTS

Nine studies (cohort = 4, cross-sectional = 5) published between 2005 and 2013 were eligible for inclusion in this review. A synthesis of findings revealed positive associations between poor quality and unhealthy diets and antenatal depressive and stress symptoms. Healthy diets were inversely associated with antenatal depressive and anxiety symptoms. Postnatal depressive symptoms demonstrated inconsistent results.

CONCLUSIONS

Given the paucity of research examining diet quality and mental health in women during the perinatal period, further sufficiently powered studies are urgently required to examine this association.

The association between dietary patterns, diabetes and depression

BACKGROUND

Type 2 diabetes and depression are commonly comorbid high-prevalence chronic disorders. Diet is a key diabetes risk factor and recent research has highlighted the relevance of diet as a possible risk for factor common mental disorders. This study aimed to investigate the interrelationship among dietary patterns, diabetes and depression.

METHODS

Data were integrated from the National Health and Nutrition Examination Study (2009-2010) for adults aged 18+ (n=4588, Mean age=43yr). Depressive symptoms were measured by the Patient Health Questionnaire-9 and diabetes status determined via self-report, usage of diabetic medication and/or fasting glucose levels ≥126mg/dL and a glycated hemoglobin level ≥6.5% (48mmol/mol). A 24-h dietary recall interview was given to determine intakes. Multiple logistic regression was employed, with depression the outcome, and dietary patterns and diabetes the predictors. Covariates included gender, age, marital status, education, race, adult food insecurity level, ratio of family income to poverty, and serum C-reactive protein.

RESULTS

Exploratory factor analysis revealed five dietary patterns (healthy; unhealthy; sweets; 'Mexican' style; breakfast) explaining 39.8% of the total variance. The healthy dietary pattern was associated with reduced odds of depression for those with diabetes (OR 0.68, 95% CI [0.52, 0.88], p=0.006) and those without diabetes (OR 0.79, 95% CI [0.64, 0.97], p=0.029) (interaction p=0.048). The relationship between the sweets dietary pattern and depression was fully explained by diabetes status.

CONCLUSION

In this study, a healthy dietary pattern was associated with a reduced likelihood of depressive symptoms, especially for those with Type 2 diabetes.

Natural environments, ancestral diets, and microbial ecology: is there a modern "paleo-deficit disorder"? Part II

Famed microbiologist René J. Dubos (1901–1982) was an early pioneer in the developmental origins of health and disease (DOHaD) construct. In the 1960s, he conducted groundbreaking research concerning the ways in which early-life experience with nutrition, microbiota, stress, and other environmental variables could influence later-life health outcomes. He recognized the co-evolutionary relationship between microbiota and the human host. Almost 2 decades before the hygiene hypothesis, he suggested that children in developed nations were becoming too sanitized (vs. our ancestral past) and that scientists should determine whether the childhood environment should be “dirtied up in a controlled manner.” He also argued that oft-celebrated growth chart increases via changes in the global food supply and dietary patterns should not be equated to quality of life and mental health. Here in the second part of our review, we reflect the words of Dubos off contemporary research findings in the areas of diet, the gut-brain-axis (microbiota and anxiety and depression) and microbial ecology. Finally, we argue, as Dubos did 40 years ago, that researchers should more closely examine the relevancy of silo-sequestered, reductionist findings in the larger picture of human quality of life. In the context of global climate change and the epidemiological transition, an allergy epidemic and psychosocial stress, our review suggests that discussions of natural environments, urbanization, biodiversity, microbiota, nutrition, and mental health, are often one in the same.

Associations between depressive symptomatology, diet, and body mass index among participants in the supplemental nutrition assistance program

BACKGROUND

Participation in the Supplemental Nutrition Assistance Program (SNAP) has been shown to increase food security, or access to adequate food; however, SNAP participation has also been associated with obesity among certain demographic groups (eg, women, but not men and children), possibly due to poorer dietary quality. Depressive symptomatology is an understudied factor, which is associated with obesity across the lifespan.

OBJECTIVE

This study examined the relationship between depressive symptomatology, dietary quality, and body weight among a sample of SNAP participants (n=639).

DESIGN

The analysis was cross-sectional; survey data were collected in May to December 2011 by trained data collectors.

PARTICIPANTS/SETTING

Adults who self-identified as the primary food shopper of the household in two predominantly low-income African-American neighborhoods characterized as "food deserts" in Pittsburgh, PA, were recruited to participate in this study.

MEASURES

Dietary quality was calculated using the US Department of Agriculture's Healthy Eating Index-2005. Body mass index (BMI; calculated as kg/m(2)) was based on objective measurements taken by the interviewer. Current depressive symptomatology was assessed by a trained interviewer using the Patient Health Questionnaire-2.

STATISTICAL ANALYSES PERFORMED

Descriptive statistics (means and percentages); two multivariate ordinary least-square regression analyses predicting BMI and dietary quality from depressive symptomatology while controlling for sociodemographic factors and food insecurity were performed.

RESULTS

Depression was a strong and statistically significant predictor of both dietary quality and BMI; higher score in depressive symptomatology was associated with lower scores in dietary quality (β=-1.26; P<0.0001). A higher score in depressive symptomatology was associated with higher BMI (β=.63; P=0.0031).

CONCLUSIONS

These findings show that depressive symptomatology is significantly associated with weight-related outcomes and suggests that understanding the risk of depression among SNAP participants could be important to understanding the relationships among SNAP participation, diet, and weight. The association between depressive symptomology, elevated BMI, and lower dietary quality among low-income, primarily African-American residents living in a food desert suggests the potential for mental health interventions to have broader benefits in this population. However, the directionality of this association is unclear and improving diet and reducing weight might also improve mental health symptoms. Additional longitudinal studies should assess these possibilities.

Associations between depression subtypes, depression severity and diet quality: cross-sectional findings from the BiDirect Study

BACKGROUND

Depression is supposed to be associated with an unhealthy lifestyle including poor diet. The objective of this study was to investigate differences in diet quality between patients with a clinical diagnosis of depression and population-based controls. Additionally, we aimed to examine effects of specific depression characteristics on diet by analyzing if diet quality varies between patients with distinct depression subtypes, and if depression severity is associated with diet quality.

METHODS

The study included 1660 participants from the BiDirect Study (n = 840 patients with depression, n = 820 population-based controls). The psychiatric assessment was based on clinical interviews and a combination of depression scales in order to provide the classification of depression subtypes and severity. Diet quality scores, reflecting the adherence to a healthy dietary pattern, were calculated on the basis of an 18-item food frequency questionnaire. Using analysis of covariance, we calculated adjusted means of diet quality scores and tested differences between groups (adjusted for socio-demographic, lifestyle-, and health-related factors).

RESULTS

We found no differences in diet quality between controls and patients with depression if depression was considered as one entity. However, we did find differences between patients with distinct subtypes of depression. Patients with melancholic depression reported the highest diet quality scores, whereas patients with atypical depression reported the lowest scores. Depression severity was not associated with diet quality.

CONCLUSIONS

Previous literature has commonly treated depression as a homogeneous entity. However, subtypes of depression may be associated with diet quality in different ways. Further studies are needed to enlighten the diet-depression relationship and the role of distinct depression subtypes.

Cognitive health and Mediterranean diet: just diet or lifestyle pattern?

Mediterranean diet is a term used to describe the traditional eating habits of people in Crete, South Italy and other Mediterranean countries. It is a predominantly plant-based diet, with olive oil being the main type of added fat. There are many observational studies exploring the potential association between adherence to the Mediterranean diet and cognitive decline. The present review focuses on longitudinal studies with repeated cognitive assessments. It also evaluates evidence on behaviors related to the Mediterranean way of living, that have been shown to be associated with cognition, namely social interaction, participation in leisure activities, including physical activities, and sleep quality. The synergistic association-effect of these lifestyle behaviors, including diet, is unknown. Lifestyle patterns may constitute a new research and public health perspective.

Adherence to a Mediterranean diet and prediction of incident stroke

BACKGROUND AND PURPOSE

There are limited data on the potential association of adherence to Mediterranean diet (MeD) with incident stroke. We sought to assess the longitudinal association between greater adherence to MeD and risk of incident stroke.

METHODS

We prospectively evaluated a population-based cohort of 30 239 individuals enrolled in REasons for Geographic and Racial Differences in Stroke (REGARDS) study, after excluding participants with stroke history, missing demographic data or food frequency questionnaires, and unavailable follow-up information. Adherence to MeD was categorized using MeD score. Incident stroke was adjudicated by expert panel review of medical records during a mean follow-up period of 6.5 years.

RESULTS

Incident stroke was identified in 565 participants (2.8%; 497 and 68 cases of ischemic stroke [IS] and hemorrhagic stroke, respectively) of 20 197 individuals fulfilling the inclusion criteria. High adherence to MeD (MeD score, 5-9) was associated with lower risk of incident IS in unadjusted analyses (hazard ratio, 0.83; 95% confidence interval, 0.70-1.00; P=0.046). The former association retained its significance (hazard ratio, 0.79; 95% confidence interval, 0.65-0.96; P=0.016) after adjustment for demographics, vascular risk factors, blood pressure levels, and antihypertensive medications. When MeD was evaluated as a continuous variable, a 1-point increase in MeD score was independently associated with a 5% reduction in the risk of incident IS (95% confidence interval, 0-11%). We documented no association of adherence to MeD with incident hemorrhagic stroke. There was no interaction of race (P=0.37) on the association of adherence to MeD with incident IS.

CONCLUSIONS

High adherence to MeD seems to be associated with a lower risk of incident IS independent of potential confounders. Adherence to MeD is not related to the risk of incident hemorrhagic stroke.

Coffee, tea, and caffeine consumption and prevention of late-life cognitive decline and dementia: a systematic review

A prolonged preclinical phase of more than two decades before the onset of dementia suggested that initial brain changes of Alzheimer's disease (AD) and the symptoms of advanced AD may represent a unique continuum. Given the very limited therapeutic value of drugs currently used in the treatment of AD and dementia, preventing or postponing the onset of AD and delaying or slowing its progression are becoming mandatory. Among possible reversible risk factors of dementia and AD, vascular, metabolic, and lifestyle-related factors were associated with the development of dementia and late-life cognitive disorders, opening new avenues for the prevention of these diseases. Among diet-associated factors, coffee is regularly consumed by millions of people around the world and owing to its caffeine content, it is the best known psychoactive stimulant resulting in heightened alertness and arousal and improvement of cognitive performance. Besides its short-term effect, some case-control and cross-sectional and longitudinal population-based studies evaluated the long-term effects on brain function and provided some evidence that coffee, tea, and caffeine consumption or higher plasma caffeine levels may be protective against cognitive impairment/decline and dementia. In particular, several cross-sectional and longitudinal population-based studies suggested a protective effect of coffee, tea, and caffeine use against late-life cognitive impairment/decline, although the association was not found in all cognitive domains investigated and there was a lack of a distinct dose-response association, with a stronger effect among women than men. The findings on the association of coffee, tea, and caffeine consumption or plasma caffeine levels with incident mild cognitive impairment and its progression to dementia were too limited to draw any conclusion. Furthermore, for dementia and AD prevention, some studies with baseline examination in midlife pointed to a lack of association, although other case-control and longitudinal population-based studies with briefer follow-up periods supported favourable effects of coffee, tea, and caffeine consumption against AD. Larger studies with longer follow-up periods should be encouraged, addressing other potential bias and confounding sources, so hopefully opening new ways for diet-related prevention of dementia and AD.

Target risk factors for dementia prevention: a systematic review and Delphi consensus study on the evidence from observational studies

OBJECTIVE

Dementia has a multifactorial etiology, but the importance of individual health and lifestyle related risk factors is often uncertain or based on few studies. The goal of this paper is to identify the major modifiable risk factors for dementia as a first step in developing an effective preventive strategy and promoting healthy late life cognitive functioning.

METHODS

A mixed-method approach combined findings from a systematic literature review and a Delphi consensus study. The literature search was conducted in PubMed and updated an earlier review by the United States National Institutes of Health from 2010. We reviewed the available evidence from observational epidemiological studies. The online Delphi study asked eight international experts to rank and weigh each risk factor for its importance for dementia prevention.

RESULTS

Out of 3127 abstracts, 291 were included in the review. There was good agreement between modifiable risk factors identified in the literature review and risk factors named spontaneously by experts. After triangulation of both methods and re-weighting by experts, strongest support was found for depression, (midlife) hypertension, physical inactivity, diabetes, (midlife) obesity, hyperlipidemia, and smoking, while more research is needed for coronary heart disease, renal dysfunction, diet, and cognitive activity.

CONCLUSIONS

Findings provide good support for several somatic and lifestyle factors and will be used to inform the design of a new multicenter trial into dementia prevention.

Dietary patterns, cognitive decline, and dementia: a systematic review

Nutrition is an important modifiable risk factor that plays a role in the strategy to prevent or delay the onset of dementia. Research on nutritional effects has until now mainly focused on the role of individual nutrients and bioactive components. However, the evidence for combined effects, such as multinutrient approaches, or a healthy dietary pattern, such as the Mediterranean diet, is growing. These approaches incorporate the complexity of the diet and possible interaction and synergy between nutrients. Over the past few years, dietary patterns have increasingly been investigated to better understand the link between diet, cognitive decline, and dementia. In this systematic review we provide an overview of the literature on human studies up to May 2014 that examined the role of dietary patterns (derived both a priori as well as a posteriori) in relation to cognitive decline or dementia. The results suggest that better adherence to a Mediterranean diet is associated with less cognitive decline, dementia, or Alzheimer disease, as shown by 4 of 6 cross-sectional studies, 6 of 12 longitudinal studies, 1 trial, and 3 meta-analyses. Other healthy dietary patterns, derived both a priori (e.g., Healthy Diet Indicator, Healthy Eating Index, and Program National Nutrition Santé guideline score) and a posteriori (e.g., factor analysis, cluster analysis, and reduced rank regression), were shown to be associated with reduced cognitive decline and/or a reduced risk of dementia as shown by all 6 cross-sectional studies and 6 of 8 longitudinal studies. More conclusive evidence is needed to reach more targeted and detailed guidelines to prevent or postpone cognitive decline.

Nutritional medicine as mainstream in psychiatry

Psychiatry is at an important juncture, with the current pharmacologically focused model having achieved modest benefits in addressing the burden of poor mental health worldwide. Although the determinants of mental health are complex, the emerging and compelling evidence for nutrition as a crucial factor in the high prevalence and incidence of mental disorders suggests that diet is as important to psychiatry as it is to cardiology, endocrinology, and gastroenterology. Evidence is steadily growing for the relation between dietary quality (and potential nutritional deficiencies) and mental health, and for the select use of nutrient-based supplements to address deficiencies, or as monotherapies or augmentation therapies. We present a viewpoint from an international collaboration of academics (members of the International Society for Nutritional Psychiatry Research), in which we provide a context and overview of the current evidence in this emerging field of research, and discuss the future direction. We advocate recognition of diet and nutrition as central determinants of both physical and mental health.

The case for diet: a safe and efficacious strategy for secondary stroke prevention

Diet is strongly associated with risk for first stroke. In particular, observational and experimental research suggests that a Mediterranean-type diet may reduce risk for first ischemic stroke with an effect size comparable to statin therapy. These data for first ischemic stroke suggest that diet may also be associated with risk for recurrent stroke and that diet modification might represent an effective intervention for secondary prevention. However, research on dietary pattern after stroke is limited and direct experimental evidence for a therapeutic effect in secondary prevention does not exist. The uncertain state of science in this area is reflected in recent guidelines on secondary stroke prevention from the American Heart Association, in which the Mediterranean-type diet is listed with only a class IIa recommendation (level of evidence C). To change guidelines and practice, research is needed, starting with efforts to better define current nutritional practices of stroke patients. Food frequency questionnaires and mobile applications for real-time recording of intake are available for this purpose. Dietary strategies for secondary stroke prevention are low risk, high potential, and warrant further evaluation.

Mediterranean diet and cognitive health: an update of available knowledge

PURPOSE OF REVIEW

Nutrition constitutes an interesting approach for the prevention of age-related brain disorders. The objective of this review was to examine the most recent evidence on the association between adherence to a Mediterranean diet (MeDi) and cognitive health among elderly individuals.

RECENT FINDINGS

Based on available epidemiological studies, two meta-analyses published in 2013 have underlined a protective effect of a greater MeDi adherence on cognitive health, including a reduced risk of Alzheimer's disease and cognitive impairment. Since then, six additional studies, from longitudinal cohorts or post-hoc analyses of randomized controlled trials conducted in the USA and Europe, have been published and provided mixed results. Potential reasons for such discrepancies include methodological limitations inherent to observational studies, and interactions between diet, environmental factors, such as those enhancing cognitive reserve, chronic diseases, and genetic factors.

SUMMARY

Overall, available evidence suggests that the MeDi might exert a long-term beneficial effect on brain functioning. However, more high-powered observational studies with long-term follow-up for cognition and randomized controlled trials assessing the impact of shifting to a MeDi on cognitive functions are still needed in various populations.

The gut microbiome and diet in psychiatry: focus on depression

PURPOSE OF REVIEW

With depressive disorders the leading source of disability globally, the identification of new targets for prevention and management is imperative. A rapidly emerging field of research suggests that the microbiome-gut-brain axis is of substantial relevance to mood and behaviour. Similarly, unhealthy diet has recently emerged as a significant correlate of and risk factor for depression. This review provides evidence for the gut microbiota as a key factor mediating the link between diet and depressive illness.

RECENT FINDINGS

The development of new technologies is affording a better understanding of how diet influences gut microbiota composition and activity and how this may, in turn, influence depressive illness. New interventions are also suggesting the possible utility of pre and probiotic formulations and fermented food in influencing mental health.

SUMMARY

Although in its early stages, the emerging field of research focused on the human microbiome suggests an important role for the gut microbiota in influencing brain development, behaviour and mood in humans. The recognition that the gut microbiota interacts bidirectionally with other environmental risk factors, such as diet and stress, suggests promise in the development of interventions targeting the gut microbiota for the prevention and treatment of common mental health disorders.

The new DSM-5 diagnosis of mild neurocognitive disorder and its relation to research in mild cognitive impairment

The Diagnostic Statistical Manual-5 (DSM-5) has included a category named the neurocognitive disorder which was formally known in DSM-IV as 'dementia, delirium, amnestic, and other cognitive disorders'. The DSM-5 distinguishes between 'mild' and 'major' neurocognitive disorders. Major neurocognitive disorder replaces the DSM-IV's term 'dementia or other debilitating conditions'. A pivotal addition is 'mild neurocognitive disorder (mNCD)' defined by a noticeable decrement in cognitive functioning that goes beyond normal changes seen in aging. It is a disorder that may progress to dementia - importantly, it may not. Presently, our understanding of mNCD is derived from research on mild cognitive impairment (MCI). Whereas there is currently no clear treatment for mNCD, many experimental therapies now and into the future will focus upon secondary prevention, namely decreasing the risk of progression to major NCD. In this article, we will focus on mNCD by reviewing the relevant literature on MCI. We will review the research on the incidence and prevalence of MCI, conversion rates from MCI to dementia, risk factors for conversion of MCI to dementia, comorbidity of MCI with other neuropsychiatric disorders (NPS), and the development of treatment strategies for neuropsychiatric disorders in MCI. The presence of NPS is common among individuals with MCI and is an important risk for progression to dementia. However, there has been little research on effective treatments for NPS in MCI. Clinicians and investigators must determine if the treatment of the NPS in mNCD will improve quality of life and help reduce the progression of the cognitive impairment.

Mediterranean diet and cognitive decline over time in an elderly Mediterranean population

PURPOSE

Evidence suggests that dietary patterns compatible with the traditional Mediterranean diet (MD) may protect against cognitive decline. We prospectively assessed whether adherence to MD in the Mediterranean country of Greece is inversely associated with cognitive decline in the elderly and whether any particular MD component may play a key role.

METHODS

Elderly men and women (N = 401) residing in the greater Athens area had dietary variables ascertained in 1994-1999. Adherence to MD was represented by the MD score [MDS, 0-3 (low), 4-5 (intermediate), 6-9 (high)]. The mini-mental state examination (MMSE) was administered by trained professionals to individuals aged 65 years or older in 2004-2006 (first assessment) and re-administered in 2011-2012 (second assessment). MMSE change (cMMSE) was categorized as: improved/unchanged (cMMSE ≥ 0), mildly lower (cMMSE -1 to -4) or substantially lower (cMMSE ≤ -5). Associations were evaluated through multinomial logistic regression.

RESULTS

Decline in MMSE performance was inversely associated with adherence to MD. For mild versus no decline, odds ratio (OR) comparing high to low MD adherence was 0.46 [95% confidence interval (CI) 0.25-0.87, p = 0.012]. For substantial versus no decline, OR comparing high to low MD adherence was 0.34 (95% CI 0.13-0.89, p = 0.025). Among the nine MDS components, only vegetable consumption exhibited a significant inverse association with cognitive decline.

CONCLUSIONS

Closer adherence to the traditional MD is highly likely to protect against cognitive decline in this elderly Mediterranean population. Higher vegetable consumption appears to play a key role, possibly in synergy with additional components of the diet.

A novel Mediterranean diet index from Lebanon: comparison with Europe

PURPOSE

To propose an index for assessing adherence to a Middle Eastern version of the Mediterranean diet as represented by the Traditional Lebanese Mediterranean diet (LMD), to evaluate the association between the LMD and selected European Mediterranean diets (EMD), and to examine socio-demographic and lifestyle correlates of adherence to Mediterranean diet (MD) among Lebanese adults.

METHODS

Using nationally representative dietary intake data of Lebanese adults, an index to measure Adherence to the LMD was derived. The choice of foods/food groups used for calculating the LMD score was based on results of previous factor analyses conducted on the same dataset. These foods/food groups included fruits, vegetables, legumes, olive oil, burghol, dairy products, starchy vegetables, dried fruits and eggs. Using Pearson's correlation and scores tertiles distributions agreement, the derived LMD index was compared to previously published EMD indexes from Greece, Spain, Italy, France and EPIC/Europe.

RESULTS

Fruits, vegetables and olive oil were common denominators to most MD scores. Food groups, specific to the LMD, included burghol, dried fruits, and eggs. The LMD score significantly correlated with the EMD scores, while being closest to the Italian (r = 0.56) and farthest from the French (r = 0.21). Percent agreement between scores' tertile distributions and Kappa statistics confirmed these findings. Multivariate linear regressions showed that older age and higher educational levels were associated with increased adherence to all MDs studied.

CONCLUSION

A novel LMD index was proposed to assess adherence to a Middle Eastern version of MD, complementing international efforts to characterize the MD and its association with disease risk.

Preventing mental health problems in offspring by targeting dietary intake of pregnant women

BACKGROUND

The concept of 'early life programming' considers the importance of very early environmental exposures throughout the gestational period on the subsequent health outcomes of offspring. The role of maternal dietary intake, specifically, has been highlighted after recent studies have shown maternal diet quality to predict mental health problems in offspring. Even in the pre-conception period, maternal nutrition can have permanent and sustained phenotypic consequences for offspring.

DISCUSSION

Here, we consider these findings in the context of the primary prevention of mental disorders and argue that interventions that target maternal diet could be of significant value.

SUMMARY

It is clear that, in order to reduce the burden of mental health issues across the lifespan, urgent action is required, particularly in the field of prevention. We thus call for the application and evaluation of targeted, primary prevention strategies that focus on dietary intake with the view to improve mental health outcomes of mothers and offspring during the postnatal period and beyond.

The incidence of the first-ever stroke in a Mediterranean island population: the isle of Lesvos stroke study

BACKGROUND

There is a paucity of research on the incidence and distribution of stroke types in Greece. This is the first study investigating stroke incidence in a Greek island, the Northern Aegean island of Lesvos (Eastern Mediterranean Sea).

METHODS

A multisource, prospective population-based register was established and subjects with first-ever stroke (FES) between June 1st 2010 and May 31st 2011 were identified.

RESULTS

197 FES subjects registered, 112 males and 85 females (mean age ± SD = 75 ± 12 years). Cerebral infarction was diagnosed in 77.7%, intracerebral hemorrhage in 12.7%, subarachnoid hemorrhage in 2.5%; undetermined stroke accounted for 7.1%. The crude annual incidence rates of FES were 227.9 (95% CI 196-260) per 100,000. Following age- and gender-standardization to the 'European' population, FES incidence rates were 117 (95% CI 99-136). Early case fatality was 20.81% (95% CI 16-27%).

CONCLUSIONS

The present findings indicate that the incidence of FES in the studied Mediterranean population is at the low end of the range of estimates established by recent European registers. The results of the present study extend the limited epidemiological data on stroke in Greece and can help guide future monitoring, prevention and treatment strategies.

Cardiovascular risk factors and future risk of Alzheimer's disease

Alzheimer's disease (AD) is the most common neurodegenerative disorder in elderly people, but there are still no curative options. Senile plaques and neurofibrillary tangles are considered hallmarks of AD, but cerebrovascular pathology is also common. In this review, we summarize findings on cardiovascular disease (CVD) and risk factors in the etiology of AD. Firstly, we discuss the association of clinical CVD (such as stroke and heart disease) and AD. Secondly, we summarize the relation between imaging makers of pre-clinical vascular disease and AD. Lastly, we discuss the association of cardiovascular risk factors and AD. We discuss both established cardiovascular risk factors and emerging putative risk factors, which exert their effect partly via CVD.

Relationship between diet and mental health in children and adolescents: a systematic review

We systematically reviewed 12 epidemiological studies to determine whether an association exists between diet quality and patterns and mental health in children and adolescents; 9 explored the relationship using diet as the exposure, and 3 used mental health as the exposure. We found evidence of a significant, cross-sectional relationship between unhealthy dietary patterns and poorer mental health in children and adolescents. We observed a consistent trend for the relationship between good-quality diet and better mental health and some evidence for the reverse. When including only the 7 studies deemed to be of high methodological quality, all but 1 of these trends remained. Findings highlight the potential importance of the relationship between dietary patterns or quality and mental health early in the life span.

Omega-3 supplementation and loneliness-related memory problems: secondary analyses of a randomized controlled trial

OBJECTIVE

Loneliness enhances risk for episodic memory declines over time. Omega-3 supplementation can improve cognitive function for people experiencing mild cognitive difficulties. Accordingly, we explored whether omega-3 supplementation would attenuate loneliness-related episodic memory problems.

METHODS

Participants (n = 138) from a parent randomized controlled trial were randomized to the placebo, 1.25 grams/d of omega-3, or 2.50 grams/d of omega-3 conditions for a 4-month period. They completed a baseline loneliness questionnaire and a battery of cognitive tests both at baseline and at the end of the randomized controlled trial.

RESULTS

After adjustment for baseline verbal episodic memory scores, lonelier people within the placebo condition had poorer verbal episodic memory postsupplementation, as measured by immediate (b = -0.28, t (117) = -2.62, p = .010) and long-delay (b = -0.06, t (116) = -2.07, p = .040) free recall, than their less lonely counterparts. This effect was not observed in the 1.25- and 2.50-grams/d supplementation groups (all p values > .10). The plasma omega-6:omega-3 ratio data mirrored these results. There were no loneliness-related effects of omega-3 supplementation on short-delay recall or the other cognitive tests (all p values > .32).

CONCLUSION

These results suggest that omega-3 supplementation attenuates loneliness-related verbal episodic memory declines over time and support the use of exploring novel interventions for treating episodic memory problems among lonely people.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00385723.

Risk of developing depressive disorders following rheumatoid arthritis: a nationwide population-based study

Background & Aims

To evaluate the risk of depressive disorders among rheumatoid arthritis (RA) by using the Taiwan National Health Insurance Research Database (NHIRD).

Methods

We conducted a retrospective study of a matched cohort of 18 285 participants (3 657 RA patients and 14 628 control patients) who were selected from the NHIRD. Patients were observed for a maximum of 10 years to determine the rates of newly diagnosed depressive disorders, and Cox regression was used to identify the risk factors associated with depressive disorders in RA patients.

Results

During the 10-year follow-up period, 205 (11.2 per 1000 person-years) RA patients and 384 (5.1 per 1000 person-years) control patients were diagnosed with depressive disorders. In RA patients, most depressive disorders (n = 163, 80%) developed with five years of being diagnosed with RA. The incidence risk ratio of depressive disorders between RA patients and control patients was 2.20 (95% confidence interval [CI], 1.84–2.61, P<.001). After adjusting for age, sex, and comorbidities, RA patients were 2.06 times more likely to develop depressive disorders (95% CI, 1.73–2.44, P<.001) compared with the control patients. Hyperthyroidism (HR = 1.67) was an independent risk factor for depressive disorders in patients with RA.

Conclusions

The likelihood of developing depressive disorders is greater among RA patients than among patients without RA. Symptoms of depression should be sought in patients with RA.

Lessons from obesity prevention for the prevention of mental disorders: the primordial prevention approach

BACKGROUND

Emerging evidence supports a relationship between risk factors for obesity and the genesis of the common mental disorders, depression and anxiety. This suggests common mental disorders should be considered as a form of non-communicable disease, preventable through the modification of lifestyle behaviours, particularly diet and physical activity.

DISCUSSION

Obesity prevention research since the 1970's represents a considerable body of knowledge regarding strategies to modify diet and physical activity and so there may be clear lessons from obesity prevention that apply to the prevention of mental disorders. For obesity, as for common mental disorders, adolescence represents a key period of vulnerability. In this paper we briefly discuss relationships between modifiable lifestyle risk factors and mental health, lifestyle risk factor interventions in obesity prevention research, the current state of mental health prevention, and the implications of current applications of systems thinking in obesity prevention research for lifestyle interventions.

SUMMARY

We propose a potential focus for future mental health promotion interventions and emphasise the importance of lessons available from other lifestyle modification intervention programmes.

Fad diets and their effect on urinary stone formation

The influence of unhealthy dietary habits on urinary stone formation has been widely recognized in literature. Dietary advice is indeed the cornerstone prescription for prevention of nephrolithiasis as well. However, only a small amount of medical literature has addressed the influence of popular or fad diets, often self-prescribed for the management of obesity and overweight or for cultural beliefs, on the risk of kidney stones. Thereby in this paper we analyze the current knowledge on the effects of some popular diets on overall lithogenic risk. High-protein diets, like Dukan diet, raise some concerns, since animal proteins are able to increase urinary calcium and to decrease urinary citrate excretion, thus leading to a high overall lithogenic risk. Low-carbohydrate diets, like Atkins diet or zone diet, may have a protective role against kidney stone formation, but there are also evidences stating that this dietary approach may rise calciuria and decrease citraturia, since it is generally associated to a relatively high intake of animal proteins. Vegan diet can be harmful for urinary stone disease, especially for the risk of hyperuricemia and micronutrient deficiencies, even if only few studies have addressed this specific matter. On the other side, the benefits of a lacto-ovo-vegetarian diet on kidney stone prevention have been largely emphasized, provided that the intake of calcium and oxalate is balanced. Traditional Mediterranean diet should exert a protective effect on nephrolithiasis as well, even if specific studies have not been carried out yet. High phytate and antioxidant content of this diet have however demonstrated to be beneficial in preventing the formation of new or recurrent calculi. Anyway, at the current state of knowledge, the most effective dietary approach to prevent kidney stone disease is a mild animal protein restriction, a balanced intake of carbohydrates and fats and a high intake of fruit and vegetables. Other fundamental aspects, which are often neglected in fad diets, are a normal intake of milk and dairy products and salt restriction. All these nutritional aspects should be greatly taken into account when patients who are willing to undergo fad or commercial diets ask for dietary advice.

Definitions and potential health benefits of the Mediterranean diet: views from experts around the world

The Mediterranean diet has been linked to a number of health benefits, including reduced mortality risk and lower incidence of cardiovascular disease. Definitions of the Mediterranean diet vary across some settings, and scores are increasingly being employed to define Mediterranean diet adherence in epidemiological studies. Some components of the Mediterranean diet overlap with other healthy dietary patterns, whereas other aspects are unique to the Mediterranean diet. In this forum article, we asked clinicians and researchers with an interest in the effect of diet on health to describe what constitutes a Mediterranean diet in different geographical settings, and how we can study the health benefits of this dietary pattern.

Nutritional psychiatry research: an emerging discipline and its intersection with global urbanization, environmental challenges and the evolutionary mismatch

In 21st-century public health, rapid urbanization and mental health disorders are a growing global concern. The relationship between diet, brain function and the risk of mental disorders has been the subject of intense research in recent years. In this review, we examine some of the potential socioeconomic and environmental challenges detracting from the traditional dietary patterns that might otherwise support positive mental health. In the context of urban expansion, climate change, cultural and technological changes and the global industrialization and ultraprocessing of food, findings related to nutrition and mental health are connected to some of the most pressing issues of our time. The research is also of relevance to matters of biophysiological anthropology. We explore some aspects of a potential evolutionary mismatch between our ancestral past (Paleolithic, Neolithic) and the contemporary nutritional environment. Changes related to dietary acid load, advanced glycation end products and microbiota (via dietary choices and cooking practices) may be of relevance to depression, anxiety and other mental disorders. In particular, the results of emerging studies demonstrate the importance of prenatal and early childhood dietary practices within the developmental origins of health and disease concept. There is still much work to be done before these population studies and their mirrored advances in bench research can provide translation to clinical medicine and public health policy. However, the clear message is that in the midst of a looming global epidemic, we ignore nutrition at our peril.

The effect of Mediterranean diet on the development of type 2 diabetes mellitus: a meta-analysis of 10 prospective studies and 136,846 participants

OBJECTIVE

The purpose of this work was to meta-analyze prospective studies that have evaluated the effect of a Mediterranean diet on the development of type 2 diabetes.

MATERIALS/METHODS

PubMed, Embase and the Cochrane Central Register of Controlled Trials databases were searched up to 20 November 2013. English language publications were allocated; 17 original research studies (1 clinical trial, 9 prospective and 7 cross-sectional) were identified. Primary analyses were limited to prospective studies and clinical trials, yielding to a sample of 136,846 participants. A systematic review and a random effects meta-analysis were conducted.

RESULTS

Higher adherence to the Mediterranean diet was associated with 23% reduced risk of developing type 2 diabetes (combined relative risk for upper versus lowest available centile: 0.77; 95% CI: 0.66, 0.89). Subgroup analyses based on region, health status of participants and number of confounders controlling for, showed similar results. Limitations include variations in Mediterranean diet adherence assessment tools, confounders' adjustment, duration of follow up and number of events with diabetes.

CONCLUSIONS

The presented results are of major public health importance, since no consensus exists concerning the best anti-diabetic diet. Mediterranean diet could, if appropriately adjusted to reflect local food availability and individual's needs, constitute a beneficial nutritional choice for the primary prevention of diabetes.

Nutraceuticals in cognitive impairment and Alzheimer's disease

Several chemical substances belonging to classes of natural dietary origin display protective properties against some age-related diseases including neurodegenerative ones, particularly Alzheimer's disease (AD). These compounds, known as nutraceuticals, differ structurally, act therefore at different biochemical and metabolic levels and have shown different types of neuroprotective properties. The aim of this review is to summarize data from observational studies, clinical trials, and randomized clinical trials (RCTs) in humans on the effects of selected nutraceuticals against age-related cognitive impairment and dementia. We report results from studies on flavonoids, some vitamins and other natural substances that have been studied in AD and that might be beneficial for the maintenance of a good cognitive performance. Due to the substantial lack of high-level evidence studies there is no possibility for recommendation of nutraceuticals in dementia-related therapeutic guidelines. Nevertheless, the strong potential for their neuroprotective action warrants further studies in the field.

Dietary patterns and the risk of depression in adults: a systematic review of observational studies

PURPOSE

Diet, a modifiable lifestyle factor, may influence the development of depression. We performed a systematic review of observational studies examining the relationship between dietary patterns and depression in healthy adults.

METHODS

A literature research was conducted searching various electronic databases up to May 2013. Study selection was based on predefined inclusion and exclusion criteria. Included studies were reviewed, and relevant data were extracted by two independent researchers. Due to a high level of heterogeneity, no meta-analysis was conducted. Therefore, main results are presented in a descriptive way.

RESULTS

In total, 16 studies met the inclusion criteria and are part of this review. Dietary patterns most commonly found were traditional/healthy patterns, Western/unhealthy patterns and Mediterranean patterns. The available literature suggests a protective effect of healthy and Mediterranean patterns, as well as a potential positive association of Western patterns and depression. However, comparison of the included studies was difficult, due to differences in relevant study characteristics and methodological limitations.

CONCLUSIONS

There are indications that dietary patterns may have influence on the onset of depression, but no firm conclusion can be drawn at this point. Further research is needed to clarify the diet-depression relationship, preferably in the form of methodological strong prospective studies using more homogeneous methods.