Low glutamate diet improves working memory and contributes to altering BOLD response and functional connectivity within working memory networks in Gulf War Illness

Adherence to unhealthy diets is associated with altered frontal gamma-aminobutyric acid and glutamate concentrations and grey matter volume: preliminary findings

OBJECTIVES

Common mental disorders (CMD) are associated with impaired frontal excitatory/inhibitory (E/I) balance and reduced grey matter volume (GMV). Larger GMV (in the areas that are implicated in CMD-pathology) and improved CMD-symptomatology have been observed in individuals who adhere to high quality diets. Moreover, preclinical studies have shown altered neurometabolites (primarily gamma-aminobutyric acid: GABA and glutamate: GLU) in relation to diet quality. However, neurochemical correlates of diet quality and how these neurobiological changes are associated with CMD and with its transdiagnostic factor, rumination, is unknown in humans. Therefore, in this study, we examined the associations between diet quality and frontal cortex neuro-chemistry and structure, as well as CMD and rumination in humans.

METHODS

Thirty adults were classified into high and low diet quality groups and underwent 1H-MRS to measure medial prefrontal cortex (mPFC) metabolite concentrations and volumetric imaging to measure GMV.

RESULTS

Low (vs High) diet quality group had reduced mPFC-GABA and elevated mPFC-GLU concentrations, as well as reduced right precentral gyrus (rPCG) GMV. However, CMD and rumination were not associated with diet quality. Notably, we observed a significant negative correlation between rumination and rPCG-GMV and a marginally significant association between rumination and mPFC-GLU concentrations. There was also a marginally significant association between mPFC-GLU concentrations and rPCG-GMV.

DISCUSSION

Adhering to unhealthy dietary patterns may be associated with compromised E/I balance, and this could affect GMV, and subsequently, rumination.

Greater resting state functional connectivity of the medial prefrontal cortex with the thalamus, caudate, and putamen in individuals who adhere to the Mediterranean style diets

PURPOSE

Healthy diets are believed to be associated with a reduced risk of experiencing common mental disorders (CMDs) and related symptomatology (such as ruminative thinking), and with healthier brain chemistry and structure, especially in the frontal regions implicated in CMDs, cognitive control, and food choice. Nevertheless, there is very limited research on the relationship between diet health/quality and brain function. In this study we assessed the associations between adherence to the Mediterranean diet and resting state functional connectivity (rs-FC) of the prefrontal cortex (PFC) with the whole brain and whether this connectivity would be associated with ruminative thinking as a transdiagnostic factor for CMDs.

METHODS

Thirty-seven adults (Mean Age = 25.57, SD = 7.18) completed the Mediterranean Diet Adherence Screener (MEDAS) and were classified into high- and low-quality diet groups and completed the Ruminative Response Scale. All participants underwent resting-state functional MRI (fMRI) to determine whole-brain rs-FC of the medial prefrontal cortex (mPFC).

RESULTS

Participants in the high MEDAS group (vs. low MEDAS group) exhibited significantly greater rs-FC of the mPFC seed with the thalamus, caudate and putamen. Additionally, the strength of rs-FC of the mPFC seed with these regions was positively associated with the MEDAS scores across groups in both crude and adjusted models. There were no significant associations between the strength of rs-FC of the mPFC seed with the cluster of voxels with the thalamus, caudate, and putamen and ruminative thinking.

DISCUSSION

This work shows that healthy dietary patterns are associated with rs-FC in the frontal-subcortical circuitry in healthy volunteers. Considering the implications of the dysregulation of this circuity, adhering to healthy dietary patterns may offer a promising alternative/complementary method to improve CMDs, cognitive control, and food choices.

"Food faddists and pseudoscientists!": Reflections on the history of resistance to ultra-processed foods

The term 'ultra-processed food' emerged in the 1980s, mostly used in reference to highly-processed convenience foods and snacks, often energy-dense, poor in nutrients, and inclusive of various synthetic additives such as emulsifiers, colors, artificial sweeteners, and/or flavor enhancers. Concern over such foods was part of the growing holistic and environmental health movements of the 1970-80s; yet, those who raised alarm about the encroachment of ultra-processed foods were often labeled, especially by industry and their powerful allies, as 'food faddists' and 'pseudoscientists'. Today, the topic of ultra-processed foods is generating massive personal, public, and planetary health interest. However, other than discussing the history of the NOVA food classification system, a useful tool that has allowed researchers to more accurately separate foods based on processing, most lay media and academic articles are ahistorical. That is, there is a tendency to present the term ultra-processed food(s) as a relatively new entrance into the lexicon, and by default, the idea that health-related pushback on ultra-processed foods is a relatively new phenomenon. This omission overlooks decades of determined advocacy and clinical work, much of it by pioneers within the holistic medicine (now integrative, functional, and lifestyle medicine) movement. Here in this reflection paper, the authors will use historical research and reporting to fill in the historical gap and articulate the saliency of why it matters.

Nutritional Criminology: Why the Emerging Research on Ultra-Processed Food Matters to Health and Justice

There is mounting concern over the potential harms associated with ultra-processed foods, including poor mental health and antisocial behavior. Cutting-edge research provides an enhanced understanding of biophysiological mechanisms, including microbiome pathways, and invites a historical reexamination of earlier work that investigated the relationship between nutrition and criminal behavior. Here, in this perspective article, we explore how this emergent research casts new light and greater significance on previous key observations. Despite expanding interest in the field dubbed 'nutritional psychiatry', there has been relatively little attention paid to its relevancy within criminology and the criminal justice system. Since public health practitioners, allied mental health professionals, and policymakers play key roles throughout criminal justice systems, a holistic perspective on both historical and emergent research is critical. While there are many questions to be resolved, the available evidence suggests that nutrition might be an underappreciated factor in prevention and treatment along the criminal justice spectrum. The intersection of nutrition and biopsychosocial health requires transdisciplinary discussions of power structures, industry influence, and marketing issues associated with widespread food and social inequalities. Some of these discussions are already occurring under the banner of 'food crime'. Given the vast societal implications, it is our contention that the subject of nutrition in the multidisciplinary field of criminology-referred to here as nutritional criminology-deserves increased scrutiny. Through combining historical findings and cutting-edge research, we aim to increase awareness of this topic among the broad readership of the journal, with the hopes of generating new hypotheses and collaborations.

Beyond Plants: The Ultra-Processing of Global Diets Is Harming the Health of People, Places, and Planet

Global food systems are a central issue for personal and planetary health in the Anthropocene. One aspect of major concern is the dramatic global spread of ultra-processed convenience foods in the last 75 years, which is linked with the rising human burden of disease and growing sustainability and environmental health challenges. However, there are also calls to radically transform global food systems, from animal to plant-derived protein sources, which may have unintended consequences. Commercial entities have moved toward this "great plant transition" with vigor. Whether motivated by profit or genuine environmental concern, this effort has facilitated the emergence of novel ultra-processed "plant-based" commercial products devoid of nutrients and fiber, and sometimes inclusive of high sugar, industrial fats, and synthetic additives. These and other ingredients combined into "plant-based" foods are often assumed to be healthy and lower in calorie content. However, the available evidence indicates that many of these products can potentially compromise health at all scales-of people, places, and planet. In this viewpoint, we summarize and reflect on the evidence and discussions presented at the Nova Network planetary health meeting on the "Future of Food", which had a particular focus on the encroachment of ultra-processed foods into the global food supply, including the plant-sourced animal protein alternatives (and the collective of ingredients therein) that are finding their way into global fast-food chains. We contend that while there has been much uncritical media attention given to the environmental impact of protein and macronutrient sources-meat vs. novel soy/pea protein burgers, etc.-the impact of the heavy industrial processing on both human and environmental health is significant but often overlooked, including effects on cognition and mental health. This calls for a more nuanced discourse that considers these complexities and refocuses priorities and value systems towards mutualistic solutions, with co-benefits for individuals, local communities, and global ecology.

Investigation of the low glutamate diet as an adjunct treatment for pediatric epilepsy: A pilot randomized controlled trial

INTRODUCTION

Current dietary therapies for epilepsy have side effects and are low in nutrients, which would make an alternative dietary treatment, which addresses these issues, advantageous. One potential option is the low glutamate diet (LGD). Glutamate is implicated in seizure activity. Blood brain barrier permeability in epilepsy could enable dietary glutamate to reach the brain and contribute to ictogenesis.

OBJECTIVE

to assess the LGD as an adjunct treatment for pediatric epilepsy.

METHODS

This study was a nonblinded, parallel, randomized clinical trial. The study was conducted virtually due to COVID-19 and registered on clinicaltrials.gov (NCT04545346). Participants were eligible if they were between the ages of 2 and 21 with ≥4 seizures per month. Baseline seizures were assessed for 1-month, then participants were allocated via block randomization to the intervention month (N=18), or a wait-listed control month followed by the intervention month (N=15). Outcome measures included seizure frequency, caregiver global impression of change (CGIC), non-seizure improvements, nutrient intake, and adverse events.

RESULTS

Nutrient intake significantly increased during the intervention. No significant differences in seizure frequency were observed between intervention and control groups. However, efficacy was assessed at 1-month compared to the standard 3-months in diet research. Additionally, 21% of participants were observed to be clinical responders to the diet. Overall health (CGIC) significantly improved in 31%, 63% experienced ≥1 non-seizure improvements, and 53% experienced adverse events. Clinical response likelihood decreased with increasing age (0.71 [0.50-0.99], p=0.04), as did the likelihood of overall health improvement (0.71 [0.54-0.92], p=0.01).

DISCUSSION

This study provides preliminary support for the LGD as an adjunct treatment before epilepsy becomes drug resistant, which is in contrast to the role of current dietary therapies in drug resistant epilepsy.