Lower Depression Scores among Walnut Consumers in NHANES

An Anti-Inflammatory Diet and Its Potential Benefit for Individuals with Mental Disorders and Neurodegenerative Diseases-A Narrative Review

This narrative review synthesizes current evidence regarding anti-inflammatory dietary patterns and their potential benefits for individuals with mental disorders and neurodegenerative diseases. Chronic low-grade inflammation is increasingly recognized as a key factor in the etiology and progression of these conditions. The review examines the evidence for the anti-inflammatory and neuroprotective properties of dietary components and food groups, focusing on whole foods rather than specific nutrients or supplements. Key dietary components showing potential benefits include fruits and vegetables (especially berries and leafy greens), whole grains, legumes, fatty fish rich in omega-3, nuts (particularly walnuts), olive oil, and fermented foods. These foods are generally rich in antioxidants, dietary fiber, and bioactive compounds that may help modulate inflammation, support gut health, and promote neuroprotection. Conversely, ultra-processed foods, red meat, and sugary beverages may be harmful. Based on this evidence, we designed the Brain Anti-Inflammatory Nutrition (BrAIN) diet. The mechanisms of this diet include the modulation of the gut microbiota and the gut-brain axis, the regulation of inflammatory pathways, a reduction in oxidative stress, and the promotion of neuroplasticity. The BrAIN diet shows promise as an aid to manage mental and neurodegenerative disorders.

Association of Tree Nut Consumption with Cardiovascular Disease and Cardiometabolic Risk Factors and Health Outcomes in US Adults: NHANES 2011-2018

Background

Tree nuts are nutrient dense, and their consumption has been associated with improvements in health outcomes.

Objective

To estimate the usual tree nut intake and examine the association between tree nut consumption and cardiometabolic (CM) health outcomes in a nationally representative sample of US adults.

Methods

Cross-sectional data were analyzed from a sample of 18,150 adults aged ≥ 20y who provided at least one reliable 24-h dietary recall and had complete data for the variables of interest in the NHANES 2011-2018. Tree nut consumers were defined as those consuming ≥ ¼ ounce/d (7.09 g). The National Cancer Institute Method was used to estimate the usual tree nut intake among consumers. Measurement error calibrated regression models were used to assess the association between tree nut consumption and each health outcome of interest.

Results

Approximately 8% of all participants (n = 1238) consumed tree nuts and had a mean ± SE usual intake of 39.5 ± 1.8 g/d. Tree nut consumers were less likely to have obesity (31% vs. 40%, P < 0.001) and low high-density lipoprotein cholesterol (22% vs. 30%, P < 0.001) compared with nonconsumers. Moreover, tree nut consumers had a lower mean waist circumference (WC) (97.1 ± 0.7 vs. 100.5 ± 0.3 cm, P < 0.001) and apolipoprotein B (87.5 ± 1.2 vs. 91.8 ± 0.5 mg/dL, P = 0.004) than nonconsumers. After adjusting models for demographics and lifestyle covariates, the difference in WC between average intake (33.7 g/d) and low threshold intake (7.09/g) of tree nuts was -1.42 ± 0.58 cm (P = 0.005).

Conclusions

Most US adults do not consume tree nuts, yet modest consumption was associated with decreased prevalence of cardiovascular disease and CM risk factors and improvement for some health outcome measures.

The Effects of Chronic Unpredictable Mild Stress and Semi-Pure Diets on the Brain, Gut and Adrenal Medulla in C57BL6 Mice

Chronic stress is known to perturb serotonergic regulation in the brain, leading to mood, learning and memory impairments and increasing the risk of developing mood disorders. The influence of the gut microbiota on serotonergic regulation in the brain has received increased attention recently, justifying the investigation of the role of diet on the gut and the brain in mood disorders. Here, using a 4-week chronic unpredictable mild stress (CUMS) model in mice, we aimed to investigate the effects of a high-fat high-glycaemic index (HFD) and high-fibre fruit & vegetable "superfood" (SUP) modifications of a semi-pure AIN93M diet on behaviour, serotonin synthesis and metabolism pathway regulation in the brain and the gut, as well as the gut microbiota and the peripheral adrenal medullary system. CUMS induced anxiety-like behaviour, dysregulated the tryptophan and serotonin metabolic pathways in the hippocampus, prefrontal cortex, and colon, and altered the composition of the gut microbiota. CUMS reduced the catecholamine synthetic capacity of the adrenal glands. Differential effects were found in these parameters in the HFD and SUP diet. Thus, dietary modifications may profoundly affect the multiple dynamic systems involved in mood disorders.

Mediterranean diet lowers all-cause and cardiovascular mortality for patients with metabolic syndrome

A Mediterranean-style diet (MED) can promote people lengthen the span of life and avoid atherosclerotic cardiovascular disease (ASCVD) in primary prevention. Metabolic syndrome (MetS) can significantly reduce life expectancy and increase the risk of ASCVD. However, few studies have focused on the role of the Mediterranean diet in patients with MetS. Participants in the National Health and Nutrition Examination Survey (NHANES) with MetS (N = 8301) from 2007 to 2018 were examined. A 9-point evaluation scorewas used to measure the degree of adherence to the MED diet. In order to compare the various levels of adherence to the MED diet and the effects of the specific MED diet components on all-cause and cardiovascular mortality, Cox regression models were utilized. Among the 8301 participants with MetS, about 13.0% (1080 of 8301) died after a median follow-up of 6.3 years. In this study, participants with MetS with adherence to high-quality and moderate-quality Mediterranean diet were significantly associated with lower all-cause mortality as well as cardiovascular mortality during the follow-up period. Futhermore, in joint analysis of the Mediterranean diet and sedentary behavior or depression, we found that high-quality or moderate-quality Mediterranean diet could attenuate, even reverse the adverse effects of sedentary behavior and depression on all-cause and cardiovascular mortality in participants with MetS. Among the components of the MED diet, greater intakes of vegetables, legumes, nuts and high MUFA/SFA ratio were significantly associated with lower all-cause mortality and greater vegetables intake was significantly associated with lower cardiovascular mortality, while more red/processed meat intake was significantly associated with higher cardiovascular mortality in participants with MetS.

Effects of Mixed Nut Consumption on Blood Glucose, Insulin, Satiety, and the Microbiome in a Healthy Population: A Pilot Study

Nuts contain many health-promoting nutrients, fiber, and phytochemicals. Nut consumption has been reported to improve several chronic disease risk factors. Most studies to date have investigated single variety nut consumption. A nut mixture may offer a more diverse array of nutrients over single variety nuts. The primary outcome of this study was to examine the effects of mixed nut consumption on postprandial glucose, insulin, and satiety in healthy young adults. Exploratory outcomes include the effects of daily nut consumption on stool microbiome and bowel movement patterns. Twenty participants were randomized to consume either 42 g of mixed nuts or 46 g of potato chips daily for 3 weeks. Mixed nut consumption did not alter postprandial blood glucose and insulin, while potato chip consumption increased glucose and insulin (P < .05). There were no significant differences in fasting blood glucose or insulin for either snack after 3 weeks of daily consumption. Both snacks increased satiety while there were no significant differences in body weight, body fat, blood pressure, waist-to-hip ratio, or anxiety. After 3 weeks of snack consumption, both groups significantly reduced straining during bowel movements while the mixed nut group slightly increased stool amount. There were no significant changes in microbiome composition for either group; however, there was a nonsignificant trend toward increased Firmicutes to Bacteroidetes ratio in the potato chip group and an opposite trend in the mixed nut group. The results of this study suggest that mixed nuts are a healthy alternative for blood sugar control. The study was registered at ClinicalTrials.gov, Number: NCT03375866.

Adding Walnuts to the Usual Diet Can Improve Diet Quality in the United States: Diet Modeling Study Based on NHANES 2015-2018

BACKGROUND

The under-consumption of calcium, potassium, fiber, and vitamin D is considered a U.S. public health concern. Shifts in eating patterns that increase the consumption of vegetables, fruits, whole grains, nuts/seeds, and dairy products can help achieve the recommended intakes of these nutrients, leading to healthier diets.

OBJECTIVE

We assessed the impact of adding 1 ounce (28.35 g) of walnuts to usual diets on diet quality and nutrients of concern, including magnesium, fiber, and potassium.

METHODS

We utilized 24 h dietary recalls obtained from the What We Eat in America, National Health and Nutrition Examination Survey (NHANES) and modeled the addition of 1 ounce (28.35 g) of walnuts to the usual diets of no-nut consumers. No-nut consumers aged ≥4 years (n = 7757) from the 2015-2018 NHANES study were included. Population percentages with intakes below the estimated average requirement (EAR) values for calcium, magnesium, folate, and vitamin E and above the adequate intake (AI) values for potassium and fiber were examined. Diet quality was assessed using the Healthy Eating Index-2015 (HEI-2015). The National Cancer Institute method was used to estimate the usual and modeled intakes. Significant differences between usual (current) and modeled intakes were determined using non-overlapping 95% confidence intervals. All analyses included sample weights to account for the NHANES survey design.

RESULTS

Adding 1 ounce (28.35 g) of walnuts to the usual diet resulted in significant reductions in the percentages of adults with intakes below the EAR for magnesium and folate (69.6% vs. 52.0%; 49.2% vs. 40.6%, respectively), and increased the percentage of adults above the AI for potassium (22.8% vs. 26.5%). A similar trend was observed among children (4-18 years). HEI scores improved significantly from 49.1 (95% CI: 48.0-50.4) to 58.5 (95% CI: 57.5-59.6) in children and from 52.4 (95% CI: 51.0-53.8) to 59.2 (95% CI: 58.0-60.5) in adults.

CONCLUSIONS

Adding 1 ounce (28.35 g) of walnuts to the usual diet of no-nut consumers improved the diet quality and adequacy of some under-consumed nutrients.

Nut Consumption and Depression: Cross-Sectional and Longitudinal Analyses in Two Cohorts of Older Adults

OBJECTIVES

To assess the cross-sectional and longitudinal associations between nut consumption and depression in two cohorts of older adults.

DESIGN, SETTING, PARTICIPANTS AND MEASUREMENTS

The first cohort (Seniors-ENRICA-I or SE-I) included a representative sample of Spanish noninstitutionalized adults aged ≥65 years interviewed in 2010 and 2013. The second cohort (SE-II) included individuals from the Madrid region, Spain, aged ≥65 years interviewed in 2017 and in 2019. Nut consumption was estimated with a validated computer-based diet history. Depression was defined as self-reported physician-diagnosed depression or the use of antidepressants. Logistic regression models were adjusted for the main confounders. The DerSimonian and Laird random-effect method was used to meta-analyze the results from both studies. A participant-level pooled analysis was conducted to examine the robustness of our analyses.

RESULTS

The SE-I included 2278 individuals (233 prevalent cases) in the cross-sectional analysis and 1534 (108 incident cases) in the longitudinal analysis; the corresponding figures for SE-II were 2726 (407 prevalent cases) and 1566 (74 incident cases). In the meta-analysis of cross-sectional results from the two studies, compared to consuming <1 serving (30 g) of nuts/week, the odds ratio (95% confidence interval) for depression was 0.90 (0.64, 1.16) for consuming 1 to <3 servings/week and 0.92 (0.70, 1.13) for consuming ≥3 servings/week; the corresponding figures for the longitudinal results were 0.90 (0.41, 1.38) and 0.66 (0.35, 0.97).

CONCLUSION

Nut consumption was associated with a lower risk of depression in a pooled longitudinal analysis using data from two cohorts of older adults. Nuts should be recommended as part of a healthy diet in older adults.

The Effects of Walnuts and Academic Stress on Mental Health, General Well-Being and the Gut Microbiota in a Sample of University Students: A Randomised Clinical Trial

Poorer mental health is common in undergraduate students due to academic stress. An interplay between stress and diet exists, with stress influencing food choices. Nutritional interventions may be effective in preventing mental health decline due to complex bidirectional interactions between the brain, the gut and the gut microbiota. Previous studies have shown walnut consumption has a positive effect on mental health. Here, using a randomized clinical trial (Australian New Zealand Clinical Trials Registry, #ACTRN12619000972123), we aimed to investigate the effects of academic stress and daily walnut consumption in university students on mental health, biochemical markers of general health, and the gut microbiota. We found academic stress had a negative impact on self-reported mood and mental health status, while daily walnut consumption improved mental health indicators and protected against some of the negative effects of academic stress on metabolic and stress biomarkers. Academic stress was associated with lower gut microbial diversity in females, which was improved by walnut consumption. The effects of academic stress or walnut consumption in male participants could not be established due to small numbers of participants. Thus, walnut consumption may have a protective effect against some of the negative impacts of academic stress, however sex-dependent mechanisms require further study.

Possible Effects and Mechanisms of Dietary Natural Products and Nutrients on Depression and Anxiety: A Narrative Review

Depression and anxiety are severe public health problems and have attracted more and more attention from researchers of food science and nutrition. Dietary natural products and nutrients, such as fish, coffee, tea, n-3 PUFA, lycopene, and dietary fiber, could play a vital role in the prevention and management of these diseases. The potential mechanisms of action mainly include inhibiting inflammation, ameliorating oxidative stress, modulating the microbiota-gut-brain axis, suppressing hypothalamic-pituitary-adrenal axis hyperactivity, and regulating the levels of monoamine neurotransmitters. In this narrative review, we summarize the most recent advancements regarding the effects of dietary natural products and nutrients on depression and anxiety, and their underlying mechanisms are discussed. We hope that this paper can provide a better understanding of the anti-depressive and anxiolytic action of dietary natural products, and that it is also helpful for developing dietary natural products for functional food, dietary supplements, or auxiliary agents for the prevention and management of these diseases.

Walnut consumption and health outcomes with public health relevance-a systematic review of cohort studies and randomized controlled trials published from 2017 to present

CONTEXT

Considering the accumulation of recent studies investigating the health effects of walnut consumption, both including and beyond cardiovascular health effects, a systematic review of this literature to investigate the strength of the evidence is warranted.

OBJECTIVE

To investigate associations between walnut consumption and outcomes with public health relevance (specifically all-cause mortality, type 2 diabetes, CVD, metabolic syndrome, obesity, cancer, neurological and mental health, musculoskeletal, gastrointestinal, and maternal disorders) and the effect on associated disease risk markers, reported in studies published from 2017 to present.

DATA SOURCES

MEDLINE, FSTA, CENTRAL, and Scopus were searched from 1 January 2017 to 5 May 2021.

DATA EXTRACTION

Human studies (cohort studies and RCTs) ≥3 weeks in duration comparing consumption of walnuts (whole, pieces, or 100% butter) to a control and measuring associations with relevant public health outcomes and disease risk markers were assessed. Key study characteristics were extracted independently by 2 investigators using a standardized table. The quality of the studies was assessed using the Cochrane Risk-of-Bias tool 2.0 and the Newcastle-Ottawa Scale.

DATA ANALYSIS

Only 1 RCT was considered to be at low risk of bias for any of its outcomes. The cohort studies were considered to be of moderate or high quality. The results were synthesized using vote counting, based on the direction of effect. Thirty-three articles, 23 describing RCTs (walnut dose ∼10-99 g/day, 1,948 subjects) and 10 describing cohort studies (∼675,928 subjects), were included. Vote counting could be performed for the blood lipids, cardiovascular function, inflammation- and hemostatic-related factors, markers of glucose metabolism, and body weight and composition outcome groupings. The results are presented in effect direction plots. With respect to blood lipids, results from 8/8 RCTs favoured walnuts, in accordance with associations with a reduced risk of CVD suggested by cohort studies; results from 6/6 RCTs favoured control with respect to body weight and composition, although most of these effects were small. This was contrary to cohort study results suggesting small benefits of walnut consumption on body weight. There was no overall consistent direction of effect for cardiovascular function, markers of glucose metabolism, or inflammation- and hemostatic-related factors.

CONCLUSIONS

Evidence published since 2017 is consistent with previous research suggesting that walnut consumption improves lipid profiles and is associated with reduced CVD risk. Evidence is accumulating in other areas, such as cognitive health, although more research is needed to draw firm conclusions.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD4202122.

Biological Role of Nutrients, Food and Dietary Patterns in the Prevention and Clinical Management of Major Depressive Disorder

Major Depressive Disorder (MDD) is a growing disabling condition affecting around 280 million people worldwide. This complex entity is the result of the interplay between biological, psychological, and sociocultural factors, and compelling evidence suggests that MDD can be considered a disease that occurs as a consequence of an evolutionary mismatch and unhealthy lifestyle habits. In this context, diet is one of the core pillars of health, influencing multiple biological processes in the brain and the entire body. It seems that there is a bidirectional relationship between MDD and malnutrition, and depressed individuals often lack certain critical nutrients along with an aberrant dietary pattern. Thus, dietary interventions are one of the most promising tools to explore in the field of MDD, as there are a specific group of nutrients (i.e., omega 3, vitamins, polyphenols, and caffeine), foods (fish, nuts, seeds fruits, vegetables, coffee/tea, and fermented products) or dietary supplements (such as S-adenosylmethionine, acetyl carnitine, creatine, amino acids, etc.), which are being currently studied. Likewise, the entire nutritional context and the dietary pattern seem to be another potential area of study, and some strategies such as the Mediterranean diet have demonstrated some relevant benefits in patients with MDD; although, further efforts are still needed. In the present work, we will explore the state-of-the-art diet in the prevention and clinical support of MDD, focusing on the biological properties of its main nutrients, foods, and dietary patterns and their possible implications for these patients.

Gender-Based Differences in the Consumption of Food Rich in Fibre and Its Relationship with Perceived Mood Status: A Cross-Sectional Study

It is unclear whether gender-based differences in dietary fibre intake exist in the relationship between daily fibre consumption and the prevalence of mood disorders. This study aims to examine the effects of dietary fibre consumption on mood status between genders in Saudi Arabia. A total of 359 Saudi participants completed the survey. The data showed that women consumed 14 g fibre/day and had a mild depression score, while men consumed 12 g/day and had very severe stress. The consumption of low-to-moderate servings of fruit or very low servings of nuts and seeds was associated with stress in men. Moderate levels of depression among women were likely to occur with low-to-moderate servings of nuts and seeds. Moderate-to-high stress levels among women appeared to be associated with low-to-moderate servings of vegetables, while depressed men consumed vegetables in low-to-moderate servings. However, anxious women who experienced mild levels consumed low-to-moderate servings of vegetables, and those with a mild-to-moderate level of anxiety consumed low-to-moderate servings of bread, whole grains, and cereals. The preliminary results showed that the consumption of 12 g fibre/day is not enough to relieve stress among men, while 14 g/day reduces the level of depression to mild among women. Fibre-rich foods, e.g., vegetables, nuts and seeds, fruit, bread, cereals and legumes, lower the degree of negative moods, but this is not only attributed to fibre, as there are other influential nutrients.

Walnut intake, cognitive outcomes and risk factors: a systematic review and meta-analysis

BACKGROUND

Walnuts contain nutrients that are associated with improved cognitive health. To our knowledge, no review has systematically examined the effects of walnuts on cognitive function and risk for cognitive decline.

OBJECTIVE

To conduct a systematic review and meta-analysis evaluating the effects of walnut intake on cognition-related outcomes and risk-factors for cognitive decline in adults.

METHODS

Medline®, Commonwealth Agricultural Bureau, and Cochrane Central Register of Controlled Trials were searched for randomized controlled trials (RCTs) and observational studies published until April 2020 on walnut intake, cognition (e.g. cognitive function, stroke, and mood), and selected risk factors for cognitive decline (e.g. glucose homeostasis and inflammation). Risk-of-bias and strength-of-evidence assessments were conducted using standard validated tools. Random-effects meta-analyses were conducted when ≥3 studies reported quantitative data for each outcome.

RESULTS

32 RCT and 7 observational study publications were included. Meta-analysis of cognition-related outcomes could not be conducted due to heterogeneity of tests. None of the 5 cognition RCTs found significant effects of walnuts on overall cognition, although 3 studies found improvements on subdomains and/or subgroups. All 7 observational studies found significant associations and a dose-response relationship between walnut intake and cognition-related outcomes. Meta-analyses of 27 RCTs reporting glucose homeostasis and inflammation outcomes, selected risk factors for cognitive decline, did not show significant effects of walnut intake.

CONCLUSIONS

Due to the non-uniformity of tests for cognition-related outcomes, definitive conclusions regarding the effect of walnut consumption on cognition could not be reached. Additionally, evidence does not show associations between walnut intake and glucose homeostasis or inflammation, cognitive decline risk-factors. High-quality studies with standardized measures are needed to clarify the role of walnuts in cognitive health.KEY MESSAGESThis is a systematic review and meta-analysis of 5 randomized clinical trials and 7 observational study articles of the impact of walnut intake on cognition decline and 27 randomized clinical trials of the effect of walnut intake on risk factors for cognitive decline including glucose homeostasis and inflammation.The non-uniformity of tests performed to measure cognitive function in the various studies did not allow for a meta-analysis of these studies. A definitive conclusion could therefore not be reached regarding the effect of walnut intake on cognitive decline.The evidence available does not show an association between walnut intake and glucose homeostasis or inflammation.

Effect of Marital Status on Depression and Mortality among Patients with Chronic Kidney Disease from National Health and Nutrition Examination Survey 2005-2014

BACKGROUND

The relationship between marital status and CKD is rarely studied. We aimed to explore the effect of marital status on the depression and mortality of patients with CKD.

METHODS

The data sources came from the NHANES database during 2005-2014 and 3,865 participants were included in this study. We used logistic regression models to examine the relationship between marital status and depression of CKD patients. The Cox proportional hazard models were used to evaluate the association between marital status and mortality of CKD patients.

RESULTS

In terms of depression in CKD patients, unmarried patients had a worse situation than married patients. Meanwhile, after adjusting the covariables, unmarried patients had increased risk of depression (OR = 1.26, 95% CI: 1.01-1.57) compared with married CKD patients, especially in males (OR = 1.45, 95% CI: 1.02-2.06) and patients with more than college education level (OR = 12.4, 95% CI: 3.75-41.02). There was a significant relationship between marital status and mortality of general CKD patients (HR = 1.36, 95% CI: 1.17-1.58). Moreover, marriage showed a protective effect against death among male patients, patients with school graduate or less and more than college educational level, patients with high income, and patients in different estimated glomerular filtration rate groups.

CONCLUSIONS

The use of large numbers of participants has revealed the effect of marital status on CKD patients. Unmarried ones had a higher risk of depression than married ones among CKD patients. Meanwhile, the risk of death was higher in unmarried ones than married ones among CKD patients in this study.

Nuts: Natural Pleiotropic Nutraceuticals

Common nuts (tree nuts and peanuts) are energy-dense foods that nature has gifted with a complex matrix of beneficial nutrients and bioactives, including monounsaturated and polyunsaturated fatty acids, high-quality protein, fiber, non-sodium minerals, tocopherols, phytosterols, and antioxidant phenolics. These nut components synergize to favorably influence metabolic and vascular physiology pathways, ameliorate cardiovascular risk factors and improve cardiovascular prognosis. There is increasing evidence that nuts positively impact myriad other health outcomes as well. Nut consumption is correlated with lower cancer incidence and cancer mortality, and decreased all-cause mortality. Favorable effects on cognitive function and depression have also been reported. Randomized controlled trials consistently show nuts have a cholesterol-lowering effect. Nut consumption also confers modest improvements on glycemic control, blood pressure (BP), endothelial function, and inflammation. Although nuts are energy-dense foods, they do not predispose to obesity, and in fact may even help in weight loss. Tree nuts and peanuts, but not peanut butter, generally produce similar positive effects on outcomes. First level evidence from the PREDIMED trial shows that, in the context of a Mediterranean diet, consumption of 30 g/d of nuts (walnuts, almonds, and hazelnuts) significantly lowered the risk of a composite endpoint of major adverse cardiovascular events (myocardial infarction, stroke, and death from cardiovascular disease) by ≈30% after intervention for 5 y. Impressively, the nut-supplemented diet reduced stroke risk by 45%. As they are rich in salutary bioactive compounds and beneficially impact various health outcomes, nuts can be considered natural pleiotropic nutraceuticals.

The Relationship of Tree Nuts and Peanuts with Adiposity Parameters: A Systematic Review and Network Meta-Analysis

The network meta-analysis and systematic review conducted aim to comparatively assess the effects of tree nuts and peanuts on body weight (BW), body mass index (BMI), waist circumference (WC), and body fat percentage (BF%). A systematic search up to 31 December 2020 was performed. A random-effects network meta-analysis was conducted following the PRISMA-NMA statement. A total of 105 randomized controlled trials (RCTs) with measures of BW (n = 6768 participants), BMI (n = 2918), WC (n = 5045), and BF% (n = 1226) were included. The transitivity assumption was met based on baseline characteristics. In the comparisons of nut consumption versus a control diet, there was no significant increase observed in any of the adiposity-related measures examined except for hazelnut-enriched diets, which raised WC. Moreover, almond-enriched diets significantly reduced WC compared to the control diet and to the pistachio-, mixed nuts-, and hazelnut-enriched diets. In subgroup analyses with only RCTs, designed to assess whether nut consumption affected weight loss, almonds were associated with reduced BMI and walnuts with reduced %BF. The evidence supports that: (1) tree nut and peanut consumption do not influence adiposity, and (2) compared to a control diet, the consumption of almond-enriched diets was associated with a reduced waist circumference.

Walnuts, Long-Chain Polyunsaturated Fatty Acids, and Adolescent Brain Development: Protocol for the Walnuts Smart Snack Dietary Intervention Trial

Background: Adolescence, when the most complex behaviors are refined to adult sophistication, represents a major window of opportunity and vulnerability for neuropsychological development. To support and protect this complex and active brain growth, different nutritional components considered essential need to be acquired from the diet. For instance, omega-3 fatty acids are mainly obtained from seafood, seeds, and walnuts. Known for their rich lipid profile, walnuts contain sizable amounts of an essential fatty acid, alpha-linolenic acid (ALA), the vegetable omega-3 fatty acid that is the precursor of two longer-chain omega-3 polyunsaturated fatty acids (omega-3 PUFA): docosahexaenoic (DHA) and eicosapentaenoic (EPA) acids. While there is growing evidence of neuropsychological improvements in the young developing brain associated with omega-3 PUFA intake, few studies have examined whether consuming walnuts during adolescence entails similar beneficial effects. There is a need to further explore the ways in which walnuts influence youthful brain function, particularly for the long-term. Thus, we designed the WALNUTs study (WSS), a population-based randomized controlled trial conducted in adolescents in Barcelona, Spain. We hypothesize that walnut intake will increase omega-3 PUFA tissue availability (particularly ALA) to a level that enhances the neuropsychological development during adolescence. Methodology/Design: We conducted a 6-month population-based randomized controlled trial in teenagers (n = 800) and we aimed to determine the effectiveness of the intervention (four walnuts per day, or 30 kernel g, ~1.5g of ALA) in enhancing brain neuropsychological and socio-emotional development compared to a control group with no walnut intervention. Before randomization, different neuropsychological tests were recorded for all participants, and blood samples (in a subsample of participants) were collected to measure omega-3 PUFA levels at baseline, and all again, after randomization and the intervention. The data is now collected and we will conduct linear regression models to assess the effect of the intervention. Discussion: The WALNUTs (WSS) study results will allow us to better understand the role of plant-based omega-3 PUFA intake from regular walnut consumption on neuropsychological development during adolescence. Results could be translated into nutritional public health recommendations targeting teenagers. Trial Registration: ClinicalTrials.gov, U.S. National Library of Medicine, National Institutes of Health # NCT02590848. Retrospectively registered 29/10/2015.

An Almond-Based Low Carbohydrate Diet Improves Depression and Glycometabolism in Patients with Type 2 Diabetes through Modulating Gut Microbiota and GLP-1: A Randomized Controlled Trial

Background: Alow carbohydrate diet (LCD) is more beneficial for the glycometabolism in type 2 diabetes (T2DM) and may be effective in reducing depression. Almond, which is a common nut, has been shown to effectively improve hyperglycemia and depression symptoms. This study aimed to determine the effect of an almond-based LCD (a-LCD) on depression and glycometabolism, as well as gut microbiota and fasting glucagon-like peptide 1 (GLP-1) in patients with T2DM. Methods: This was a randomized controlled trial which compared an a-LCD with a low-fat diet (LFD). Forty-five participants with T2DM at a diabetes club and the Endocrine Division of the First and Second Affiliated Hospital of Soochow University between December 2018 to December 2019 completed each dietary intervention for 3 months, including 22 in the a-LCD group and 23 in the LFD group. The indicators for depression and biochemical indicators including glycosylated hemoglobin (HbA1c), gut microbiota, and GLP-1 concentration were assessed at the baseline and third month and compared between the two groups. Results: A-LCD significantly improved depression and HbA1c (p < 0.01). Meanwhile, a-LCD significantly increased the short chain fatty acid (SCFAs)-producing bacteria Roseburia, Ruminococcus and Eubacterium. The GLP-1 concentration in the a-LCD group was higher than that in the LFD group (p < 0.05). Conclusions: A-LCD could exert a beneficial effect on depression and glycometabolism in patients with T2DM. We speculate that the role of a-LCD in improving depression in patients with T2DM may be associated with it stimulating the growth of SCFAs-producing bacteria, increasing SCFAs production and GPR43 activation, and further maintaining GLP-1 secretion. In future studies, the SCFAs and GPR43 activation should be further examined.

The Association of Race/Ethnicity, Dietary Intake, and Physical Activity with Depression

OBJECTIVE

This study investigated the association of race/ethnicity, dietary intake, and physical activity with depression and potential other barriers associated with the use of mental health services among depressed people.

METHODS

We used the nationally representative data, 2011-2016 National Health and Nutrition Examination Survey. Depression status was defined using a Patient Health Questionnaire. Multivariable logistic regressions were conducted on depression status and the use of mental health specialists among depressed adults, accounting for the complex sampling design.

RESULTS

The prevalence of depression was 8.3% with substantial racial/ethnic differences (8.0% for white, 3.1% for Asian, 9.2% for black, 7.6% for Mexican Hispanics, 13.0% for other Hispanics). Good/acceptable diet and a high level of physical activity were negatively associated with depression. Among depressed people, no significant racial/ethnic differences were observed in using mental health specialists.

CONCLUSION

Prevalence for depression was lower among people who have good or acceptable diet and moderate physical activity. These modifiable factors as well as race/ethnicity should be incorporated into psychotherapeutic interventions to improve depression.

Effect of a 12-Week Almond-Enriched Diet on Biomarkers of Cognitive Performance, Mood, and Cardiometabolic Health in Older Overweight Adults

Long term nut consumption is associated with reduced risk of coronary heart disease and better cognitive function. This study examined supplementing habitual diets with almonds or carbohydrate-rich snack foods (providing 15% energy) on biomarkers of cardiovascular and metabolic health, mood and cognitive performance. Participants (overweight/obese, 50-80 years) were randomised to an almond-enriched diet (AED) or isocaloric nut-free diet (NFD) for 12 weeks. Body weight, blood lipids, glucose, insulin, blood pressure (BP), arterial stiffness, cell adhesions molecules, C reactive protein (CRP), mood, and cognitive performance (working memory primary outcome), dietary profiles and energy intake/expenditure were measured at baseline and Week 12 in 128 participants (n = 63 AED, n = 65 NFD). Compared with NFD, AED was associated with altered macro and micronutrient profiles, but no differences in energy intake or expenditure. The AED significantly reduced triglycerides and SBP but there were no other changes in cardiometabolic biomarkers, mood, or cognitive performance. The inclusion of almonds in the diet improves aspects of cardiometabolic health without affecting cognitive performance or mood in overweight/obese adults.

Legume and nut consumption in relation to depression, anxiety and psychological distress in Iranian adults

PURPOSE

Although considerable research has been devoted to the link between consumption of legume and nuts and metabolic abnormalities, few studies have examined legume and nut consumption in relation to psychological disorders. The current study aimed to examine the association of legume and nut consumption with depression, anxiety and psychological distress in Iranian adults.

METHODS

This cross-sectional study was carried out among 3172 adult participants aged 18-55 years. Assessment of legume and nut consumption was conducted using a validated dish-based 106-item semi-quantitative food frequency questionnaire. The Iranian validated version of Hospital Anxiety and Depression Scale (HADS) was used to examine psychological health. Scores of 8 or more on either subscale in the questionnaire were considered to indicate the presence of depression or anxiety. Data on psychological distress were collected using the General Health Questionnaire (GHQ), in which the score of 4 or more was considered as having psychological distress.

RESULTS

The mean age of participants was 36.5 ± 7.9 years. In the fully adjusted model, men in the top quintile of legume and nut consumption were 66% less likely to be anxious than those in the bottom quintile (OR 0.34; 95% CI 0.14-0.82). However, such significant relationship was not observed among women (OR 1.06; 95% CI 0.63-1.77). We failed to find any other significant association between legume and nut consumption and depression or psychological distress after adjustment for potential confounders either in men or women.

CONCLUSIONS

We found that consumption of legume and nuts was associated with lower odds of anxiety in men, but not in women. No other significant association was seen among participants. Legume and nut consumption might be promising and, along with medications, could be used to prevent, control or delay psychological disorders.

Beneficial Effects of Walnuts on Cognition and Brain Health

Oxidative stress and neuroinflammation have important roles in the aging process, mild cognitive impairment (MCI), Alzheimer’s disease (AD), and other brain disorders. Amyloid beta protein (Aβ) is the main component of amyloid plaques in the brains of people with AD. Several studies suggest that Aβ increases the generation of free radicals in neurons, which leads to oxidative damage and cell death. Aβ can also induce neuroinflammation by increasing pro-inflammatory cytokines and enzymes. Walnuts contain several components that have antioxidant and anti-inflammatory effects. Animal and human studies from our and other groups suggest that supplementation with walnuts in the diet may improve cognition and reduce the risk and/or progression of MCI and AD. In the transgenic AD mouse model (AD-tg), we have reported the beneficial effects of a diet with walnuts on memory, learning, motor coordination, anxiety, and locomotor activity. Human clinical trials have also suggested an association of walnut consumption with better cognitive performance and improvement in memory when compared to baseline in adults. Our recent study in AD-tg mice has shown that a walnut-enriched diet significantly improves antioxidant defense and decreases free radicals’ levels, lipid peroxidation, and protein oxidation when compared to a control diet without walnuts. These findings suggest that a diet with walnuts can reduce oxidative stress by decreasing the generation of free radicals and by boosting antioxidant defense, thus resulting in decreased oxidative damage to lipids and proteins. An in vitro study with synthetic Aβ showed that walnut extract can inhibit Aβ fibrillization and solubilize the preformed Aβ fibrils, suggesting an anti-amyloidogenic property of walnuts. Because it takes many years for cognitive impairment and dementia to develop, we suggest that early and long-term dietary supplementation with walnuts may help to maintain cognitive functions and may reduce the risk of developing, or delay the onset and/or slow the progression of, MCI and dementia by decreasing Aβ fibrillization, reducing oxidative damage, increasing antioxidant defense, and decreasing neuroinflammation. Furthermore, several animal and human studies have suggested that walnuts may also decrease the risk or progression of other brain disorders such as Parkinson’s disease, stroke, and depression, as well as of cardiovascular disease and type 2 diabetes. Together, these reports suggest the benefits of a walnut-enriched diet in brain disorders and in other chronic diseases, due to the additive or synergistic effects of walnut components for protection against oxidative stress and inflammation in these diseases.

Health Benefits of Nut Consumption in Middle-Aged and Elderly Population

Aging is considered the major risk factor for most chronic disorders. Oxidative stress and chronic inflammation are two major contributors for cellular senescence, downregulation of stress response pathways with a decrease of protective cellular activity and accumulation of cellular damage, leading in time to age-related diseases. This review investigated the most recent clinical trials and cohort studies published in the last ten years, which presented the influence of tree nut and peanut antioxidant diets in preventing or delaying age-related diseases in middle-aged and elderly subjects (≥55 years old). Tree nut and peanut ingestion has the possibility to influence blood lipid count, biochemical and anthropometric parameters, endothelial function and inflammatory biomarkers, thereby positively affecting cardiometabolic morbidity and mortality, cancers, and cognitive disorders, mainly through the nuts' healthy lipid profile and antioxidant and anti-inflammatory mechanisms of actions. Clinical evidence and scientific findings demonstrate the importance of diets characterized by a high intake of nuts and emphasize their potential in preventing age-related diseases, validating the addition of tree nuts and peanuts in the diet of older adults. Therefore, increased consumption of bioactive antioxidant compounds from nuts clearly impacts many risk factors related to aging and can extend health span and lifespan.