Beneficial effect of pistachio consumption on glucose metabolism, insulin resistance, inflammation, and related metabolic risk markers: a randomized clinical trial

Glycaemic Response to a Nut-Enriched Diet in Asian Chinese Adults with Normal or High Glycaemia: The Tū Ora RCT

Nut-based products are a good source of high-quality plant protein in addition to mono- and polyunsaturated fatty acids, and may aid low-glycaemic dietary strategies important for the prevention of type 2 diabetes (T2D). In particular, they may be advantageous in populations susceptible to dysglycaemia, such as Asian Chinese. The present study aimed to compare effects of a higher-protein nut bar (HP-NB, also higher in total fibre and unsaturated fats, comprising mixed almonds and peanuts) vs. an isoenergetic higher-carbohydrate cereal bar (HC-CB) within the diet of 101 Chinese adults with overweight and normo- or hyperglycaemia. Ectopic pancreas and liver fat were characterised using magnetic resonance imaging and spectroscopy (MRI/S) as a secondary outcome. Participants were randomized to receive HP-NB or HC-CB daily as a 1 MJ light meal or snack replacement, in addition to healthy eating advice. Anthropometry and clinical indicators of T2D risk were assessed fasted and during an oral glucose tolerance test (OGTT), pre- and post-intervention. No significant difference was observed between diet groups for body weight, body mass index, waist or hip circumference, blood pressure, glucoregulatory markers, lipid profile or inflammatory markers over 12 weeks (all, p > 0.05). No difference was observed between glycaemic subgroups or those with normal versus high ectopic organ fat. Although HP-NB can attenuate postprandial glycaemia following a meal, no effects were observed for either fasting or glucose-mediated outcomes following longer-term inclusion in the habitual diet of Chinese adults with overweight, including at-risk subgroups.

Intake of Pistachios as a Nighttime Snack Has Similar Effects on Short- and Longer-Term Glycemic Control Compared with Education to Consume 1-2 Carbohydrate Exchanges in Adults with Prediabetes: A 12-Wk Randomized Crossover Trial

BACKGROUND

Nut intake is associated with better glycemic control and lower cardiovascular disease (CVD) risk. It remains unclear if nut intake timing affects glycemic control and CVD risk factors. Intake of pistachios as a nighttime snack may attenuate morning glucose production and lower fasting plasma glucose (FPG).

OBJECTIVES

We assessed the effects of a nighttime (after dinner and before bedtime) pistachio snack (57 g/d) on glycemic control markers, vascular health, lipids/lipoproteins, and diet quality compared with education to consume 1-2 carbohydrate (CHO) exchanges (usual care) in individuals with prediabetes.

METHODS

A 2-period, randomized crossover trial was conducted. Participants were provided 57 g/d of dry roasted unsalted pistachios (319 kcal; fat 26 g; CHO 16 g; protein 12 g; fiber 6 g) as a nighttime snack or received usual care for 12 wk. Primary (FPG) and secondary outcomes [hemoglobin A1c (HbA1c), insulin, Homeostatic Model Assessment for Insulin Resistance (HOMA-IR), lipids/lipoproteins, vascular health, and Healthy Eating Index-2015 (HEI-2015)] were measured before and after each condition.

RESULTS

A total of 66 participants (50.9 ± 11.6 y, FPG: 106.2 ± 6.4 mg/dL) were randomly assigned, and 51 participants completed the trial. No between-condition differences in FPG {0.9 mg/dL [95% confidence interval (CI): -1.2, 3.1]}, HbA1c, insulin, HOMA-IR, lipids/lipoproteins, blood pressure, or vascular health were observed. The HEI-2015 score was higher after the pistachio condition [6.8 points (95% CI: 1.5, 12.1)] than after usual care driven by higher component scores for seafood and plant proteins [2.0 points (95% CI: 1.0, 2.9)], refined grains [2.3 points (95% CI: 1.1, 3.5)], and the fatty acid ratio [1.7 points (95% CI: 0.0, 3.5)].

CONCLUSIONS

In adults with prediabetes, consuming 57 g/d of pistachios as a nighttime snack increased diet quality but had similar effects on glycemic markers, lipids/lipoproteins, blood pressure, and vascular health compared with the usual care comparator. Pistachios may be a healthful alternative to carbohydrate-rich nighttime snacks to increase alignment with Dietary Guidelines for Americans. This trial was registered at clinicaltrials.gov as NCT04056208.

Effects of energy-restricted diets with or without nuts on weight, body composition and glycaemic control in adults: a scoping review

Energy-restricted (ER) diets promote weight loss and improve body composition and glycaemic control. Nut consumption also improves these parameters. However, less is known about the combined benefit of these two strategies. This scoping review implemented a systematic search of Medline, Embase and Scopus to identify randomised controlled trials evaluating the effect of ER diets with or without nuts on body mass, body composition and glycaemic control in adults. After reviewing titles and abstracts, twenty-nine full-text articles were screened, resulting in seven studies reported in eight papers that met the inclusion criteria. Energy restriction was achieved by prescribing a set energy target or reducing intake by 1000-4200 kJ from daily energy requirements. Interventions ranged from 4 to 52 weeks in duration and contained 42-84 g/d of almonds, peanuts, pistachios or walnuts. While all studies reported that energy restriction resulted in significant weight loss, the addition of nuts to ER diets demonstrated significantly greater weight loss in only approximately half of the included studies (4/7 studies). There was limited evidence to support additional benefits from nuts for body composition measures or glycaemic control. Although improvements in weight loss and glycaemia were not consistent when nuts were included in ER diets, no study revealed an adverse effect of nut consumption on health outcomes. Future studies could explore the effect of consuming different types and amounts of nuts, combined with various levels of energy restriction on weight, body composition and glycaemic control.

Association of nut consumption with insulin resistance and blood lipid profile in Spanish university students

AIMS

To examine whether nut consumption was associated with insulin resistance and blood lipid parameters in a sample of young healthy adults.

MATERIAL AND METHODS

A cross-sectional study was conducted involving 306 first-year students (aged 18-30 years) from the University of Castilla-La Mancha, Spain. Biochemical variables related to insulin resistance and blood lipid profile (glucose, insulin, HbA1c, total cholesterol (total-c), LDL-c, HDL-c, and triglycerides) were determined from morning fasting blood samples. Nut consumption was estimated using a 137-item Food-Frequency Questionnaire. The associations of walnuts, other nuts and total nut intakes with insulin resistance and lipid profile variables and surrogates were assessed by linear regression analysis. Differences in insulin resistance and lipid profiles between participants meeting or not meeting the nut consumption recommendations were examined by analysis of covariance (ANCOVA). Logistic regressions were used to analyze the likelihood of having higher levels of blood lipids or insulin resistance in participants who met or did not meet the recommended intake of nuts.

RESULTS

There was no association found between nut consumption, whether walnuts or other nut varieties, and insulin resistance and lipid profile variables. Additionally, there were no significant differences in insulin resistance or blood lipid profile variables between university students meeting or not meeting nut consumption recommendations. Finally, stratified analyses based on sex were consistent and did not substantially modify our estimates in the fully adjusted models.

CONCLUSIONS

In conclusion, our results suggest that walnuts, other types of nuts, and total nut consumption did not adversely influence metabolic or lipid profile variables among healthy young adults. Although nuts are recommended among healthy dietary patterns, our findings showed that nut consumption has a null effect on the cardiometabolic risk parameters explored in young healthy adults.

A 4-Week Pecan-Enriched Diet Improves Postprandial Lipid Peroxidation in Aging Adults

Pecans are rich in bioactive compounds known to reduce oxidative stress and provide glucoregulatory benefits. Few studies assessing the effect of a pecan-enriched diet on such health outcomes suggest potential improvements to cardiometabolic health; however, this has not been studied in an older adult population. Thus, we aimed to examine the effect of daily pecan consumption for 4-weeks on fasting and postmeal antioxidant status, oxidative stress, and markers of glycemia in healthy aging adults. In this randomized, parallel, controlled trial, 41 healthy adults (50-75 years) either consumed 68 g of pecans/day (pecan; n = 21) or avoided all nuts (control; n = 20). At pre- (V1) and postintervention visits (V2), blood samples were obtained at fasting, and 30, 60, and 120 min following a high saturated fat meal to assess changes in malondialdehyde, which is a measure of lipid peroxidation, total antioxidant capacity (TAC), glucose, and insulin. Across the intervention, there were no differences in fasting or postprandial TAC, glucose, or insulin for pecan versus control. There was a trend for a difference in fasting lipid peroxidation from V1 to V2 by treatment (P = .06) driven by a slight reduction for pecan versus control (Δpecan: -2.0 ± 1.1 vs. Δcontrol: +0.6 ± 0.8 μM). In addition, postprandial lipid peroxidation was suppressed at V2 for pecan, and this was different from control (pecan areas under the curve (AUC): 10.6 ± 1.3 μM/h to 9.1 ± 1.2 μM/h vs. control AUC: 8.9 ± 1.3 μM/h to 9.2 ± 1.1 μM/h; P = .03). These findings suggest that a 1 month, pecan-enriched diet is protective against postmeal oxidative stress. Longer interventions or a diabetic population may be needed to observe glucoregulatory benefits. Clinical Trial Registration: NCT04385537.

Tree Nut and Peanut Consumption and Risk of Cardiovascular Disease: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Cardiovascular disease (CVD) is the leading cause of death globally. Habitual consumption of tree nuts and peanuts is associated with cardioprotective benefits. Food-based dietary guidelines globally recommend nuts as a key component of a healthy diet. This systematic review and meta-analysis were conducted to examine the relationship between tree nut and peanut consumption and risk factors for CVD in randomized controlled trials (RCTs) (PROSPERO: CRD42022309156). MEDLINE, PubMed, CINAHL, and Cochrane Central databases were searched up to 26 September, 2021. All RCT studies that assessed the effects of tree nut or peanut consumption of any dose on CVD risk factors were included. Review Manager software was used to conduct a random effect meta-analysis for CVD outcomes from RCTs. Forest plots were generated for each outcome, between-study heterogeneity was estimated using the I2 test statistic and funnel plots and Egger's test for outcomes with ≥10 strata. The quality assessment used the Health Canada Quality Appraisal Tool, and the certainty of the evidence was assessed using grading of recommendations assessment, development, and evaluation (GRADE). A total of 153 articles describing 139 studies (81 parallel design and 58 cross-over design) were included in the systematic review, with 129 studies in the meta-analysis. The meta-analysis showed a significant decrease for low-density lipoprotein (LDL) cholesterol, total cholesterol (TC), triglycerides (TG), TC:high-density lipoprotein (HDL) cholesterol, LDL cholesterol:HDL cholesterol, and apolipoprotein B (apoB) following nut consumption. However, the quality of evidence was "low" for only 18 intervention studies. The certainty of the body of evidence for TC:HDL cholesterol, LDL cholesterol:HDL cholesterol, and apoB were "moderate" because of inconsistency, for TG were "low," and for LDL cholesterol and TC were "very low" because of inconsistency and the likelihood of publication bias. The findings of this review provide evidence of a combined effect of tree nuts and peanuts on a range of biomarkers to create an overall CVD risk reduction.

The Association of Lifestyle Patterns with Prediabetes in Adults from Families at High Risk for Type 2 Diabetes in Europe: The Feel4Diabetes Study

The increasing prevalence of prediabetes globally does not bode well for the growing epidemic of type 2 diabetes (T2D) and its complications. Yet there is a lack of studies regarding lifestyle patterns (LPs) and their association with prediabetes. The present study aimed to examine the association of different LPs with the existence of prediabetes in adults from families at high risk for T2D in Europe. In total, 2759 adults (66.3% females) from six European countries were included in this cross-sectional analysis using data from the baseline assessment of the Feel4Diabetes study. Anthropometric, sociodemographic, dietary and behavioral data were assessed, and fasting blood glucose measurements were also obtained. LPs were derived via principal component analysis. Two LPs were derived, explaining 32% of the total variation. LP 1 was characterized by breakfast consumption, high consumption of fruits and berries, vegetables and nuts and seeds, and low consumption of salty snacks and soft drinks with sugar, while LP 2 was characterized by high consumption of salty and sweet snacks, soft drinks with sugar and juice with sugar and sedentary behavior. After adjusting for various confounders, LP 2 was positively associated with the existence of prediabetes (odds ratio = 1.02, 95% CI 1.01-1.04), while LP 1 was not significantly associated with prediabetes. Understanding LPs would provide necessary evidence for planning intervention and education strategies for prediabetes and T2D.

Effects of pistachios on glycaemic control: a systematic review and meta-analysis of randomised controlled trials

To evaluate the effects of pistachio consumption on the glucoregulatory status in individuals with a high risk of CVD, a systematic review and meta-analysis of randomised controlled trials (RCT) were conducted. Online databases including PubMed, Scopus, Web of Science and Cochrane Library were searched from inception until June 2019. Human trials that reported data for fasting blood sugar (FBS), fasting insulin and homeostasis model assessment of insulin resistance (HOMA-IR) were included. Data were pooled using the random effect models and expressed as weighted mean difference (WMD) with 95 % CI. Eight RCTs were included in the analyses. Pistachio consumption, exchanged isocalorically for other foods, decreased FBS (WMD: -5·32 mg/dl, 95 % CI (-7·80, -2·64), P < 0·001) and insulin (WMD: -1·86 µIU/ml, 95 % CI (-3·13, -0·59), P < 0·01) concentrations in individuals with a high risk of CVD. However, no changes were observed in the levels of HOMA-IR between the groups (WMD: -0·66, 95 % CI (-1·89, 0·58), P = 0·30). Pistachio consumption may improve glucoregulatory status in individuals at risk for CVD, as evidenced by reduced FBS and insulin concentrations. However, due to the limited availability of studies with diabetic cases and relatively small sample sizes of available studies, well-designed trials with adequate sample sizes aimed at diabetic populations are recommended.

Believe It or 'Nut': Why It Is Time to Set the Record Straight on Nut Protein Quality: Pistachio (Pistacia vera L.) Focus

There are growing public health movements to transition towards diets that are plant-based. However, confusion exists with concerns that plant-based proteins (including nuts) may be inferior with respect to protein quality. The present publication evaluates the evolution of protein quality concepts and explains the protein science related to pistachios. Pistachio nuts are a plant-based complete protein providing all nine EAAs in addition to an array of nutrients and phytochemicals. They have a PDCAAS of 73 and 81%, (raw and roasted pistachios, respectively), higher than that of many other tree nuts. From an environmental perspective transitioning towards plant-based diets (including nuts) could have potential to reduce total/green water footprints. Dietary guidelines are evolving yet nuts such as pistachios do not always have a clear place within these. Now appears to be a pertinent time to look at protein quality from the perspective of whole daily diets and dietary patterns, factoring in both health and environmental outcomes. Given updated modes of thinking, nuts such as pistachios have an important role to play in terms of providing ready-to-eat, good-quality, plant-based protein within daily diets.

The effect of nuts consumption on circulating oxidized low-density lipoproteins: A systematic review and meta-analysis of randomized controlled trials

This systematic review and meta-analysis evaluated the effect of nuts in decreasing circulating levels of oxidized low-density lipoproteins (ox-LDL). A literature search was performed of major electronic databases (MEDLINE/PubMed, Scopus, and ISI Web of Science) from inception up to November 15th, 2021 to find randomized controlled trials (RCTs) evaluating the effect of different nuts on circulating levels of ox-LDL. The effect size was determined using standardized mean difference (SMD) and corresponding 95% confidence intervals (CI). Evaluation of funnel plot, Begg's rank correlation, and Egger's weighted regression tests were used to assess the presence of publication bias in the meta-analysis. This systematic review and meta-analysis included 15 RCTs involving 997 subjects. Meta-analysis showed that nuts significantly decreased serum levels of ox-LDL. Besides, meta-regression results of the association between confounders such as duration of nuts consumption or delta LDL-cholesterol and levels of ox-LDL, were not significant. The correlation between nuts type and ox-LDL levels was significant in subgroup analyses suggesting the most significant effect of pistachios consumption on reducing the circulating concentrations of ox-LDL. To conclude, nuts consumption decreases the circulating concentrations of ox-LDL which might be beneficial for the prevention and/or progression of ASCVD.

Effect of Nuts on Markers of Inflammation and Oxidative Stress: A Narrative Review

Oxidative stress and inflammation are mediators in the pathophysiology of several non-communicable diseases (NCDs). Tree nuts and peanuts lower risk factors of cardiometabolic disease, including blood lipids, blood pressure and insulin resistance, among others. Given their strong antioxidant/anti-inflammatory potential, it is plausible that nuts may also exert a favorable effect on inflammation and oxidative stress. Evidence from systematic reviews and meta-analyses of cohort studies and randomized controlled trials (RCTs) suggest a modest protective effect of total nuts; however, the evidence is inconsistent for specific nut types. In this narrative review, the state of evidence to date is summarized for the effect of nut intake on biomarkers of inflammation and oxidative stress, and an attempt is made to define the gaps in research while providing a framework for future research. Overall, it appears that some nuts, such as almonds and walnuts, may favorably modify inflammation, and others, such as Brazil nuts, may favorably influence oxidative stress. There is a pressing need for large RCTs with an adequate sample size that consider different nut types, and the dose and duration of nut intervention, while evaluating a robust set of biomarkers for inflammation and oxidative stress. Building a stronger evidence base is important, especially since oxidative stress and inflammation are mediators of many NCDs and can benefit both personalized and public health nutrition.

Nuts and seeds consumption and risk of cardiovascular disease, type 2 diabetes and their risk factors: a systematic review and meta-analysis

Objectives

We aimed to systematically review studies and evaluate the strength of the evidence on nuts/seeds consumption and cardiometabolic diseases and their risk factors among adults.

Methods

A protocol was pre-registered in PROSPERO (CRD42021270554). We searched MEDLINE, Embase, Cochrane Central Register of Controlled Trials and Scopus up to September 20, 2021 for prospective cohort studies and ≥12-week randomized controlled trials (RCTs). Main outcomes were cardiovascular disease (CVD), coronary heart disease (CHD), stroke and type 2 diabetes (T2D), secondary total-/low density lipoprotein (LDL)-cholesterol, blood pressure and glycaemic markers. Data extraction and risk of bias (RoB) assessments (using RoB 2.0 and RoB-NObS) were performed in duplicate. Effect sizes were pooled using random-effects meta-analyses and expressed as relative risk (RR) or weighted mean differences with 95% confidence intervals (CI); heterogeneity quantified as I ². One-stage dose-response analyses assessed the linear and non-linear associations with CVD, CHD, stroke and T2D. The strength of evidence was classified per the World Cancer Research Fund criteria.

Results

After screening 23,244 references, we included 42 papers from cohort studies (28 unique cohorts, 1,890,573 participants) and 18 RCTs (2,266 participants). In the cohorts, mainly populations with low consumption, high versus low total nuts/seeds consumption was inversely associated with total CVD (RR 0.81; 95% CI 0.75, 0.86; I ² = 67%), CVD mortality (0.77; 0.72, 0.82; I ² = 59.3%), CHD (0.82; 0.76, 0.89; I ² = 64%), CHD mortality (0.75; 0.65, 0.87; I ² = 66.9%) and non-fatal CHD (0.85; 0.75, 0.96; I ² = 62.2%). According to the non-linear dose-response analyses, consumption of 30 g/day of total nuts/seeds was associated with RRs of similar magnitude. For stroke and T2D the summary RR for high versus low intake was 0.91 (95% CI 0.85, 0.97; I ² = 24.8%) and 0.95 (0.75, 1.21; I ² = 82.2%). Intake of nuts (median ~50 g/day) lowered total (-0.15 mmol/L; -0.22, -0.08; I ² = 31.2%) and LDL-cholesterol (-0.13 mmol/L; -0.21, -0.05; I ² = 68.6%), but not blood pressure. Findings on fasting glucose, HbA1c and insulin resistance were conflicting. The results were robust to sensitivity and subgroup analyses. We rated the associations between nuts/seeds and both CVD and CHD as probable. There was limited but suggestive evidence for no association with stroke. No conclusion could be made for T2D.

Conclusion

There is a probable relationship between consumption of nuts/seeds and lower risk of CVD, mostly driven by CHD, possibly in part through effects on blood lipids. More research on stroke and T2D may affect the conclusions. The evidence of specific nuts should be further investigated.

Acute feeding with almonds compared to a carbohydrate-based snack improves appetite-regulating hormones with no effect on self-reported appetite sensations: a randomised controlled trial

PURPOSE

Early satiety has been identified as one of the mechanisms that may explain the beneficial effects of nuts for reducing obesity. This study compared postprandial changes in appetite-regulating hormones and self-reported appetite ratings after consuming almonds (AL, 15% of energy requirement) or an isocaloric carbohydrate-rich snack bar (SB).

METHODS

This is a sub-analysis of baseline assessments of a larger parallel-arm randomised controlled trial in overweight and obese (Body Mass Index 27.5-34.9 kg/m²) adults (25-65 years). After an overnight fast, 140 participants consumed a randomly allocated snack (AL [n = 68] or SB [n = 72]). Appetite-regulating hormones and self-reported appetite sensations, measured using visual analogue scales, were assessed immediately before snack food consumption, and at 30, 60, 90 and 120 min following snack consumption. A sub-set of participants (AL, n = 49; SB, n = 48) then consumed a meal challenge buffet ad libitum to assess subsequent energy intake. An additional appetite rating assessment was administered post buffet at 150 min.

RESULTS

Postprandial C-peptide area under the curve (AUC) response was 47% smaller with AL compared to SB (p < 0.001). Glucose-dependent insulinotropic polypeptide, glucagon and pancreatic polypeptide AUC responses were larger with AL compared to SB (18%, p = 0.005; 39% p < 0.001; 45% p < 0.001 respectively). Cholecystokinin, ghrelin, glucagon-like peptide-1, leptin and polypeptide YY AUCs were not different between groups. Self-reported appetite ratings and energy intake following the buffet did not differ between groups.

CONCLUSION

More favourable appetite-regulating hormone responses to AL did not translate into better self-reported appetite or reduced short-term energy consumption. Future studies should investigate implications for longer term appetite regulation.

ANZCTR REFERENCE NUMBER

ACTRN12618001861246 2018.

Nuts as a Dietary Enrichment with Selected Minerals-Content Assessment Supported by Chemometric Analysis

Nuts used as a snack and meal accompaniment supply plant protein and fatty acids that are beneficial for human health; however, they can also provide minerals. The aim of this study was to determine the content of selected elements that are often deficient in the diet (calcium, potassium, magnesium, selenium, and zinc) in nuts and determine whether they can be used to supplement deficiencies in the diet. In this study, we analyzed 10 types of nuts (n = 120 samples) that are consumed and available for sale in Poland. The content of calcium, magnesium, selenium, and zinc was determined by the atomic absorption spectrometry method, and flame atomic emission spectrometry was used for determination of potassium contents. The highest median calcium content was found in almonds (2825.8 mg/kg), the highest potassium content in pistachio nuts (15,730.5 mg/kg), the highest magnesium and selenium contents in Brazil nuts (10,509.2 mg/kg and 4348.7 μg/kg, respectively), and the highest zinc content in pine nuts (72.4 mg/kg). All the tested nuts are a source of magnesium, eight types of tested nuts are a source of potassium, six nut types are a source of zinc, and four nut types are a source of selenium; however, among the tested nuts, only almonds can be considered a source of calcium. Moreover, we found that selected chemometric methods can be useful in the classification of nuts. The studied nuts are valuable products that can be used to supplement the diet with selected minerals and can therefore be labelled as functional products crucial for disease prevention.

Why Should Pistachio Be a Regular Food in Our Diet?

The pistachio is regarded as a relevant source of biologically active components that, compared to other nuts, possess a healthier nutritional profile with low-fat content composed mainly of monounsaturated fatty acids, a high source of vegetable protein and dietary fibre, remarkable content of minerals, especially potassium, and an excellent source of vitamins, such as vitamins C and E. A rich composition in terms of phytochemicals, such as tocopherols, carotenoids, and, importantly, phenolic compounds, makes pistachio a powerful food to explore its involvement in the prevention of prevalent pathologies. Although pistachio has been less explored than other nuts (walnut, almonds, hazelnut, etc.), many studies provide evidence of its beneficial effects on CVD risk factors beyond the lipid-lowering effect. The present review gathers recent data regarding the most beneficial effects of pistachio on lipid and glucose homeostasis, endothelial function, oxidative stress, and inflammation that essentially convey a protective/preventive effect on the onset of pathological conditions, such as obesity, type 2 diabetes, CVD, and cancer. Likewise, the influence of pistachio consumption on gut microbiota is reviewed with promising results. However, population nut consumption does not meet current intake recommendations due to the extended belief that they are fattening products, their high cost, or teething problems, among the most critical barriers, which would be solved with more research and information.

Quantification of Phytochemicals, Cellular Antioxidant Activities and Antiproliferative Activities of Raw and Roasted American Pistachios (Pistacia vera L.)

The consumption of pistachios has been linked to many potential health benefits. Phytochemicals in pistachios, including phenolics, vitamin E and carotenoids, have been considered to make contributions to the health benefits. The objectives of this study were (1) to explore the phytochemical profiles (total phenolics and total flavonoids, including both free and bound forms), selected phytochemicals, vitamin E and carotenoids of raw and roasted pistachios; (2) to determine total antioxidant activity and cellular antioxidant activity (CAA); and (3) to explore antiproliferative activities of pistachio extracts against human breast, liver and colon cancer cells in vitro. Both raw and roasted pistachios contained high total phenolics, at 479.9 ± 10.2 (raw) and 447.9 ± 9.4 (roasted) mg GAE/100 g, respectively, and high flavonoids, at 178.4 ± 10.6 (raw) and 144.1 ± 7.4 (roasted) mg GAE/100 g, respectively. The contributions of the free form to the total phenolics in pistachios were 82% (raw) and 84% (roasted), respectively, and the contributions of the free form to the total flavonoids in pistachios were 65% (raw) and 70% (roasted), respectively. Gentisic acid and catechin were the major phenolics in raw and roasted pistachios, respectively. Both raw and roasted pistachios had similar total antioxidant activity evaluated by Oxygen-Radical-Scavenging Capacity (ORAC) assay, at 7387.9 ± 467 (raw) and 7375.3 ± 602 (roasted) μmol TE/100 g, respectively. Both raw and roasted pistachio extracts exhibited cellular antioxidant activity inhibiting peroxyradical radical-induced oxidation, with CAA values of 77.39 ± 4.25 (wash) and 253.71 ± 19.18 (no wash) μmol QE/100 g of raw pistachios and 115.62 ± 3.02 (wash) and 216.76 ± 6.6 (no wash) μmol QE/100 g of roasted pistachios. Roasted pistachios contained more vitamin E when compared with raw pistachios, while raw pistachios contained more carotenoids than the roasted pistachios. Additionally, the free form of roasted pistachios extracts exhibited superior antiproliferation activity against HepG2, Caco-2 and MDA-MB-231 cancer cells in a dose-dependent manner, with EC₅₀ 34.73 ± 1.64, 36.66 ± 3.3 and 7.41 ± 0.82 mg per mL, respectively. These results provided new knowledge about the phytochemical profiles, antioxidant activity, cellular antioxidant activity and antiproliferative activity of raw and roasted pistachios.

Adherence to the Mediterranean Diet in Pregnancy and Its Benefits on Maternal-Fetal Health: A Systematic Review of the Literature

Introduction

Pregnancy is a transcendent period for the mother and the fetus, characterized by an increase on energy requirements. Mediterranean diet (MD) is considered a healthy eating pattern that can provide the nutritional requirements of pregnancy and protect from the development of obstetric pathologies.

Objective

To know the relationship between adherence to the MD and its maternal-fetal benefits.

Methodology

A systematic review was conducted by identifying articles in the PubMed and Cochrane databases. The publication date of the studies was between 2010 and 2020, and the inclusion criteria established were that the articles were written in English and Spanish and were accessible in full text. Studies concerning assisted reproduction, gene modulation, conference abstracts, systematic reviews, and pilot studies were excluded.

Results

Finally, a total of 14 studies were included in the review. The association between the MD and the reduction of some pathologies of pregnancy, such as gestational diabetes, overweight or obesity, sleep quality, complications of childbirth, urinary tract infections (UTIs), and alterations in fetal growth was demonstrated, as well as perinatal problems, including birth weight, prematurity, gastroschisis, and other childhood problems.

Conclusion

The MD is an optimal diet to consume during pregnancy.

Nuts as a Part of Dietary Strategy to Improve Metabolic Biomarkers: A Narrative Review

Background

Nuts are in the spotlight because of their association with improved health outcomes. We aimed to summarize the findings of previous studies to evaluate the impact of nuts consumption on glycaemic and lipid profile, inflammation, and oxidative stress.

Methods

Electronic searches for observational and intervention studies were undertaken in PubMed, Embase, Web of Science, and Science Direct until 2022 for searching the studies aiming the application of different types of nuts and the beneficial effects of nuts in improving glycemia, dyslipidemia, inflammation, and oxidative stress.

Results

Results from 56 interventional, 9 narrative and 3 systematic reviews, and 12 meta-analysis studies, aiming at the evaluating beneficial effects of different types of nuts on metabolic markers, showed that nut consumption could improve metabolic markers, including glycaemic factors, lipid profile, and inflammatory and oxidative stress parameters in both healthy and individuals with metabolic disorders in a type-, dose- and duration-dependent manner. According to their unique nutrient components, nuts can be known as a part of a healthy diet, resulting in improved metabolic biomarkers.

Conclusion

Considering the efficacy of nuts in improving metabolic markers, incorporation of, incorporating nuts the effectiveness of nuts in improving metabolic markers, incorporating nuts in the diet may prevent the incidence or aggravation of chronic metabolic diseases. Considering the health benefits of the nuts' components, including essential micronutrients, if consumed in the appropriate dose and duration to provide the necessary amount of effective micronutrients to improve health, we will see an improvement in metabolic factors. At the same time, more research is required to determine the optimal type, dose, and duration of nut intervention with regards to metabolic control and reducing the risk of developing metabolic disorders.

Pistachio Nuts (Pistacia vera L.): Production, Nutrients, Bioactives and Novel Health Effects

Epidemiological and clinical studies have indicated positive outcomes related to tree nut consumption. Here, we review the production, nutrient, phytochemical composition and emerging research trends on the health benefits of pistachio nuts (Pistacia vera L.). Pistachios are a good source of protein, fiber, monounsaturated fatty acids, minerals and vitamins, as well as carotenoids, phenolic acids, flavonoids and anthocyanins. Polyphenols in pistachios are important contributors to the antioxidant and anti-inflammatory effect, as demonstrated in vitro and in vivo through animal studies and clinical trials. The antimicrobial and antiviral potential of pistachio polyphenols has also been assessed and could help overcome drug resistance. Pistachio consumption may play a role in cognitive function and has been associated with a positive modulation of the human gut microbiota and beneficial effects on skin health. Pistachio polyphenol extracts may affect enzymes involved in glucose regulation and so type 2 diabetes. Taken together, these data demonstrate the health benefits of including pistachios in the diet. Further studies are required to investigate the mechanisms involved.

Consumption of pistachio nuts positively affects lipid profiles: A systematic review and meta-analysis of randomized controlled trials

We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to evaluate the effects of consuming pistachio nuts on lipid profiles (total cholesterol [TC], low-density lipoprotein cholesterol [LDL-C], high-density lipoprotein cholesterol [HDL-C], and triglyceride [TG]). Databases of PubMed, Scopus, ISI Web of Science, and Cochrane Library were searched from inception to June 2019 to identify RCTs documenting the effects of consuming pistachio nuts on blood lipid profiles in adults. Effect sizes were reported as weighted mean difference (WMD) and 95% confidence interval (CI) using the random-effects models (DerSimonian-Laird method). Twelve eligible RCTs were included. Consumption of pistachio nuts decreased TC (WMD: -7.48 mg/dL; 95% CI, -12.62 to -2.34), LDL-C (WMD: -3.82 mg/dL; 95% CI, -5.49 to -2.16) and TG (WMD: -11.19 mg/dL; 95% CI, -14.21 to -8.17) levels. However, HDL-cholesterol levels (WMD: 2.45 mg/dL; 95% CI, -2.44 to 7.33) did not change following pistachio consumption. Consuming pistachio nuts may improve lipid profiles (TC, LDL-C, TG) in adults and may be protective against cardiometabolic diseases. However, further studies with larger sample sizes are required to confirm these results.

Are fatty nuts a weighty concern? A systematic review and meta-analysis and dose-response meta-regression of prospective cohorts and randomized controlled trials

Nuts are recommended for cardiovascular health, yet concerns remain that nuts may contribute to weight gain due to their high energy density. A systematic review and meta-analysis of prospective cohorts and randomized controlled trials (RCTs) was conducted to update the evidence, provide a dose-response analysis, and assess differences in nut type, comparator and more in subgroup analyses. MEDLINE, EMBASE, and Cochrane were searched, along with manual searches. Data from eligible studies were pooled using meta-analysis methods. Interstudy heterogeneity was assessed (Cochran Q statistic) and quantified (I² statistic). Certainty of the evidence was assessed by Grading of Recommendations Assessment, Development, and Evaluation (GRADE). Six prospective cohort studies (7 unique cohorts, n = 569,910) and 86 RCTs (114 comparisons, n = 5873) met eligibility criteria. Nuts were associated with lower incidence of overweight/obesity (RR 0.93 [95% CI 0.88 to 0.98] P < 0.001, "moderate" certainty of evidence) in prospective cohorts. RCTs presented no adverse effect of nuts on body weight (MD 0.09 kg, [95% CI -0.09 to 0.27 kg] P < 0.001, "high" certainty of evidence). Meta-regression showed that higher nut intake was associated with reductions in body weight and body fat. Current evidence demonstrates the concern that nut consumption contributes to increased adiposity appears unwarranted.

PARP-1-Associated Pathological Processes: Inhibition by Natural Polyphenols

Poly (ADP-ribose) polymerase-1 (PARP-1) is a nuclear enzyme involved in processes of cell cycle regulation, DNA repair, transcription, and replication. Hyperactivity of PARP-1 induced by changes in cell homeostasis promotes development of chronic pathological processes leading to cell death during various metabolic disorders, cardiovascular and neurodegenerative diseases. In contrast, tumor growth is accompanied by a moderate activation of PARP-1 that supports survival of tumor cells due to enhancement of DNA lesion repair and resistance to therapy by DNA damaging agents. That is why PARP inhibitors (PARPi) are promising agents for the therapy of tumor and metabolic diseases. A PARPi family is rapidly growing partly due to natural polyphenols discovered among plant secondary metabolites. This review describes mechanisms of PARP-1 participation in the development of various pathologies, analyzes multiple PARP-dependent pathways of cell degeneration and death, and discusses representative plant polyphenols, which can inhibit PARP-1 directly or suppress unwanted PARP-dependent cellular processes.

Plant-based snacking: research and practical applications of pistachios for health benefits

Pistachio nuts are a nutrient-dense source of good quality plant protein, commonly consumed as a minimally processed snack food or ingredient. The present paper is based on a symposium held during the 13th FENS (Federation of European Nutrition Societies) 2019 conference in Dublin that explored recent research and practical applications of pistachios as a plant-based snack, in particular, for appetite control and healthy weight management; and for glycaemic control during pregnancy. Individual nut types, whilst similar in nutritional composition, have unique characteristics which may have a significant impact on potential health effects. Recognising this, the further purpose here is to explore future research needs for pistachios, based on work completed to date and the discussion that ensued among researchers at this event, in order to advance the full scope of health benefits from pistachios, in particular, taking into account of both sustainability and nutritional health.

Pecan-Enriched Diets Alter Cholesterol Profiles and Triglycerides in Adults at Risk for Cardiovascular Disease in a Randomized, Controlled Trial

BACKGROUND

Research indicates that tree nuts are cardioprotective, but studies on pecans are limited.

OBJECTIVES

We examined the impact of daily pecan consumption on blood lipids and glycemia in adults at-risk for cardiovascular disease (CVD).

METHODS

This was a randomized, controlled trial where 56 adults (BMI ≥28 kg/m2 or hypercholesterolemia) were randomly allocated into a control group (n = 18) or 1 of 2 pecan groups. The ADD group (n = 16) consumed pecans (68 g) as part of a free-living diet. The SUB group (n = 18) substituted the pecans (68 g) for isocaloric foods from their diet. At baseline and 8 wk, a high-fat meal was consumed with 4-h postprandial blood draws to determine changes in blood lipids and glycemia.

RESULTS

There was a significant reduction from baseline to 8 wk in fasting total cholesterol (TC) (204 ± 8.76 to 195 ± 8.12; 205 ± 8.06 to 195 ± 6.94 mg/dL), LDL cholesterol (143 ± 8.09 to 129 ± 7.71; 144 ± 6.60 to 135 ± 6.16 mg/dL), triglycerides (TGs) (139 ± 12.1 to 125 ± 14.6; 133 ± 10.7 to 120 ± 10.3 mg/dL), TC/HDL cholesterol ratio (3.92 ± 0.206 to 3.58 ± 0.175; 4.08 ± 0.167 to 3.79 ± 0.151), non-HDL cholesterol (151 ± 8.24 to 140 ± 7.95; 155 ± 6.87 to 143 ± 6.00 mg/dL), and apolipoprotein B (99.1 ± 5.96 to 93.0 ± 5.35; 104 ± 3.43 to 97.1 ± 3.11 mg/dL) in the ADD and SUB groups, respectively (P ≤ 0.05 for all), with no changes in control. There was a reduction in postprandial TGs (P ≤ 0.01) in ADD, and a reduction in postprandial glucose (P < 0.05) in SUB.

CONCLUSIONS

Pecan consumption improves fasting and postprandial blood lipids in CVD at-risk adults. This trial was registered at clinicaltrials.gov as NCT04376632.

Association of nut consumption with risk of total cancer and 5 specific cancers: evidence from 3 large prospective cohort studies

BACKGROUND

The associations between nut consumption and cancer risk have not been extensively investigated.

OBJECTIVES

We aimed to examine the associations between nut consumption, especially specific types of nuts (peanut, tree nut, walnut, and tree nut other than walnut), and cancer risk.

METHODS

Nut consumption was assessed by FFQ at baseline and updated every 2-4 y in the Nurses' Health Study (1980-2014), the Nurses' Health Study II (1991-2015), and the Health Professionals Follow-up Study (1986-2018). We examined the associations between the intake of total and specific types of nuts and risk of total cancer and common cancers, including lung, colorectal, breast, bladder, and aggressive prostate cancer. Cox proportional-hazards models were used to obtain the HRs and 95% CIs in each cohort as well as pooled.

RESULTS

During 5,873,671 person-years of follow-up in 180,832 women and 45,560 men, we documented 44,561 incident cancer cases. As compared with nonconsumers, the pooled multivariable HRs of total nut consumption for ≥5 times/wk were 0.99 (95% CI: 0.94, 1.04; P-trend = 0.54) for total cancer, 0.88 (95% CI: 0.74, 1.04; P-trend = 0.18) for lung cancer, 1.07 (95% CI: 0.92, 1.26; P-trend = 0.89) for colorectal cancer, 0.90 (95% CI: 0.71, 1.14; P-trend = 0.65) for bladder cancer, 0.96 (95% CI: 0.85, 1.08; P-trend = 0.36) for breast cancer, and 1.18 (95% CI: 0.92, 1.51; P-trend = 0.52) for aggressive prostate cancer.

CONCLUSIONS

In 3 large prospective cohorts, frequent nut consumption was not associated with risk of total cancer and common individual cancers.

Effects of pistachios on anthropometric indices, inflammatory markers, endothelial function and blood pressure in adults: a systematic review and meta-analysis of randomised controlled trials

Evidence suggests that eating nuts may reduce the risk of CVD. This study was intended to pool the data of all randomised controlled trials (RCT) available to determine if pistachios confer a beneficial effect on anthropometric indices, inflammatory markers, endothelial dysfunction and blood pressure. Without language restriction, PubMed, Scopus, Cochrane Library and Web of Science were searched for articles published from the earliest records to June 2019 investigating the effect of pistachio consumption on inflammation, endothelial dysfunction and hypertension. Mean difference (MD) was pooled using a random effects model. The Cochrane risk of bias tool was used to evaluate the quality of the studies. The meta-analysis of thirteen RCT with 563 participants indicated that pistachio consumption significantly decreased systolic blood pressure (SBP) (MD: -2·12 mmHg, 95 % CI -3·65, -0·59, P = 0·007), whereas changes in flow-mediated dilation (MD: 0·94 %, 95 % CI -0·99, 2·86, P = 0·813), diastolic blood pressure (MD: 0·32 mmHg, 95 % CI -1·37, 2·02, P = 0·707), C-reactive protein (MD: 0·00 mg/l, 95 % CI -0·21, 0·23, P = 0·942), TNF-α (MD: -0·09 pg/ml, 95 % CI -0·38, 0·20, P = 0·541), body weight (MD: 0·09 kg, 95 % CI -0·38, 0·69, P = 0·697), BMI (MD: 0·07 kg/m2, 95 % CI -0·16, 0·31, P = 0·553) and waist circumference (MD: 0·77 cm, 95 % CI -0·09, 1·64, P = 0·140) were not statistically significant. This systematic review and meta-analysis suggested the efficacy of pistachio consumption to reduce SBP levels. However, further large-scale studies are needed to confirm these results.

Does a MediDiet with additional extra virgin olive oil (EVOO) and pistachios reduce the incidence of gestational diabetes?

OBJECTIVE

The present study aimed to evaluate gestational diabetes mellitus (GDM) incidence in pregnant women following the Mediterranean diet with additional extra virgin olive oil (EVOO) and pistachios.

METHODS

560 pregnant patients were enrolled in the present study. The Mediterranean diet (MedDiet) was introduced in both the interventional group (IG) and control group (CG). The females received 40 ml of extra virgin olive oil (EVOO) every day along with 25 - 30 gm of roasted pistachios in the interventional group. The incidence of Gestational Diabetes Mellitus (GDM) was recorded along with specific maternal and neonatal outcomes.

MATERIALS AND METHODS

The nutritional and MEDAS scores were not statistically different among the groups at baseline, but the difference was statistically significant and higher in IG at 24-28 weeks (p = 0.001) and 36-38 weeks (p = 0.001). GDM was diagnosed in 51(20.4%) females in the Control group and 34 (13.6%) females in the Interventional group. The MedDiet significantly reduced the GDM incidence (p=0.02) after adjusting the confounding factors.

CONCLUSION

The present study depicts that dietary intervention in pregnant women, including MedDiet and increased consumption of EVOO and pistachios, decreased the incidence of GDM.

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.

Health Benefits Related to Tree Nut Consumption and Their Bioactive Compounds

Long-term studies with regular tree nut consumption have indicated positive outcomes for multiple health benefits. Here, we review the beneficial effects of tree nuts, highlighting the impact on glucose modulation, body weight management, cardiovascular risk, inflammation, oxidative stress, cognitive performance, and gut microbiota. Nuts are important sources of nutrients and phytochemicals, which, together with a healthy lipid profile, could help prevent certain chronic diseases, protect against oxidative stress and inflammation, and improve cognitive performance, thus reducing the impact of aging and neurodegeneration.

Effect of tree nuts on glycemic outcomes in adults with type 2 diabetes mellitus: a systematic review

OBJECTIVE

The objective of this review was to synthesize the best available research evidence regarding the effectiveness of tree nuts on glycemic outcomes in adults with type 2 diabetes mellitus.

INTRODUCTION

There has been an increase in the use of complementary therapy, particularly botanical products, for management of type 2 diabetes mellitus. It has been reported that increasing mono- and polyunsaturated fatty acids in diet effectively lowers the risk of development of type 2 diabetes mellitus. Hence, it was hypothesized that consumption of nuts, which are high in polyunsaturated fatty acids and mono-unsaturated fatty acids, may aid in preventing diabetes and reducing levels of blood glucose by reducing glycemic load by displacing dietary carbohydrates present in diet.

INCLUSION CRITERIA

This systematic review included randomized controlled trials that compared the consumption of any type and form of tree nut with a placebo or any other intervention in adults with type 2 diabetes mellitus. Trials were included if they measured fasting blood glucose, postprandial blood glucose, and/or glycated hemoglobin. Trials that assessed triglyceride levels and weight postintervention were also considered for inclusion. Trials were restricted to the English language.

METHODS

A three step search of PubMed, CINAHL, Embase, Trip database, and Cochrane Central Register of Controlled Trials (CENTRAL) was done in July 2019. To find unpublished studies, ClinicalTrials.gov and Google Scholar were searched. Studies from the search were reviewed against the inclusion criteria by two reviewers. The JBI critical appraisal checklist for randomized controlled trials was used to assess the potential studies for methodological quality. A meta-analysis and subgroup analysis was conducted among trials with the same type of intervention and outcome measures. Results are presented in a narrative format where statistical pooling was not possible.

RESULTS

Fifteen trials were included with a total sample size of 667. Consumption of pistachios demonstrated a significant reduction in triglyceride levels (mmol/L) at three month or earlier follow-up (mean difference [MD] -0.28; confidence interval -0.33, -0.23; P <0.00001). The meta-analysis including all tree nuts combined showed reduction in both fasting blood glucose and glycated hemoglobin (MD -0.26 mmol/L and -0.11% respectively) at three month or earlier follow-up. The subgroup analysis demonstrated MD of -0.45, -0.16, and -0.90 mmol/L in fasting blood glucose following ingestion of walnuts, almonds, and hazelnuts, respectively, and -0.17% in glycated hemoglobin following ingestion of walnuts at three month or earlier follow-up. Although not clinically significant, these figures give an indication that further research with larger sample sizes and longer follow-up may show encouraging results.

CONCLUSIONS

The authors found that pistachio consumption for three months or less significantly reduced triglyceride levels. Other tree nuts (walnuts, almonds, and hazelnuts) reduced fasting blood glucose and glycated hemoglobin levels by varying degrees. Further robust randomized controlled trials with power calculation-based sample size, comparing same type, dose, and method of nut intervention, will provide more evidence. For now, clinical decisions should be based on standard practice local guidelines.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO CRD42019133558.

A higher-protein nut-based snack product suppresses glycaemia and decreases glycaemic response to co-ingested carbohydrate in an overweight prediabetic Asian Chinese cohort: the Tū Ora postprandial RCT

Nut-based products may aid low-glycaemic dietary strategies that are important for diabetes prevention in populations at increased risk of dysglycaemia, such as Asian Chinese. This randomised cross-over trial assessed the postprandial glycaemic response (0-120 min) of a higher-protein nut-based (HP-NB) snack formulation, in bar format (1009 kJ, Nutrient Profiling Score, NPS, -2), when compared with an iso-energetic higher-carbohydrate (CHO) cereal-based bar (HC-CB, 985 kJ, NPS +3). It also assessed the ability to suppress glucose response to a typical CHO-rich food (white bread, WB), when co-ingested. Ten overweight prediabetic Chinese adults (mean, sd: age 47⋅9, 15⋅7 years; BMI 25⋅5, 1⋅6 kg/m2), with total body fat plus ectopic pancreas and liver fat quantified using dual-energy X-ray absorptiometry and magnetic resonance imaging and spectroscopy, received the five meal treatments in random order: HP-NB, HC-CB, HP-NB + WB (50 g available CHO), HC-CB + WB and WB only. Compared with HC-CB, HP-NB induced a significantly lower 30-120 min glucose response (P < 0⋅05), with an approximately 10-fold lower incremental area under the glucose curve (iAUC0-120; P < 0⋅001). HP-NB also attenuated glucose response by approximately 25 % when co-ingested with WB (P < 0⋅05). Half of the cohort had elevated pancreas and/or liver fat, with 13-21 % greater suppression of iAUC0-120 glucose in the low v. high organ fat subgroups across all five treatments. A nut-based snack product may be a healthier alternative to an energy equivalent cereal-based product with evidence of both a lower postprandial glycaemic response and modulation of CHO-induced hyperglycaemia even in high-risk, overweight, pre-diabetic adults.

Prevalence of lipase producer Aspergillus niger in nuts and anti-biofilm efficacy of its crude lipase against some human pathogenic bacteria

Nuts are the natural source of healthy lipids, proteins, and omega-3. They are susceptible to fungal and mycotoxins contamination because of their high nutritional value. Twenty-five species comprising 12 genera were isolated from 80 samples of dried fruits and nuts using the dilution plate method. Peanut recorded the highest level of contamination followed by coconut; almond and raisin were the lowest. Aspergillus was the most prevalent genus and A.niger, was the most dominant species. The morphological identification of the selected A.niger isolates as they were detected in high frequency of occurrence was confirmed by using 18SrRNA sequence. Ochratoxin biosynthesis gene Aopks was detected in the tested isolates. Lipase production by the selected A.niger isolates was determined with enzyme activity index (EAI) ranging from 2.02 to 3.28. A.niger-26 was the highest lipase producer with enzyme activity of 0.6 ± 0.1 U/ml by the trimetric method. Lip2 gene was also detected in the tested isolates. Finally, the antibacterial and antibiofilm efficiency of crude lipase against some human pathogens was monitored. Results exhibited great antibacterial efficacy with minimum bactericidal concentration (MBC) of 20 to 40 µl/100 µl against Escherichiacoli, Pseudomonasaeruginosa, Proteusmirabilis, and Methicillin-resistant Staphylococcusaureus (MRSA). Interestingly, significant anti-biofilm efficacy with inhibition percentages of 95.3, 74.9, 77.1 and 93.6% was observed against the tested pathogens, respectively.

Measuring the health effects of food by metabolomics

Metabolomics of human biological fluids or tissues is used to discover markers for diseases by comparing the metabolome of the patients against healthy individuals. Ultimately, these markers can be used in drug discovery to determine how medications normalize (at least in part) the human metabolome at specific disease stages to homeostatic. Likewise, the health effects of food can be studied. Even metabolomics of the food can be combined with metabolomics of the treated patients to correlate compounds from food with measurable health effects from clinical studies. Various chemometric analyses of these metabolomics data are used to identify markers for diseases and to obtain evidence for health effects. This review discusses recent researches (published from 2013 to 2021) on whether specific dietary intervention to humans suffering from metabolic disorders may improve their pathological status. The scope is limited to those associated with major lifestyle diseases such as diabetes, obesity, and cardiovascular diseases, for which food is thought may have detrimental as well as beneficial effects on human health. It includes metabolites characterization of different biological samples such as the human serum/plasma, urine, saliva, feces, or ileal fluid. Whether the study results supported the claimed health benefits and whether the research was conducted with appropriate study design, was criticized.

Socioeconomic and lifestyle factors modifies the association between nut consumption and metabolic syndrome incidence

BACKGROUND & AIMS

The aim of this study was to evaluate the association of nut consumption and its various types with metabolic syndrome (MetS) risk and to investigate whether lifestyle factors (physical activity and smoking status) and socioeconomic status (education and occupation) modulate the association of nut consumption and the risk of MetS.

METHODS

We prospectively studied 1915 participants of the Tehran Lipid and Glucose study, among whom 591 were diagnosed with MetS during 8.9 years of follow-up. Nut consumption and its various types were assessed using a validated semi-quantitative food frequency questionnaire. Multivariable adjusted Cox regression was used to estimate Hazard Ratios (HRs) for MetS events across tertiles of nut consumption and its various types. Regarding interaction between nut consumption and physical activity levels, education levels, and smoking status on the risk of MetS, using joint classification, the effect modification of lifestyle factors and socioeconomic status on the association between nut consumption (<median and ≥ median) and risk of MetS was assessed by Cox regression.

RESULTS

Nut consumption was inversely associated with MetS risk in multivariable-adjusted models. The highest tertiles of the constituents of nuts including fiber, polyphenol, MUFA and PUFA reduced MetS risk compared with the lowest tertiles, after adjustment for confounders. Among various types of nuts, the multivariable-adjusted HRs of MetS were 0.78 (0.63-0.96) for walnuts, and 0.77 (0.63-0.94) for pistachios, compared with the lowest intake. Among adult population, consuming nuts higher than the median and having moderate to high physical activity levels resulted in significant reduction in the MetS risk (HRs: 0.74, CI: 0.55-0.98 for moderate and HRs: 0.63, CI: 0.47-0.86 for high physical activity level). Participants who did not smoke had lower risk of MetS regardless of their amount of nuts consumption (HRs: 0.67, CI: 0.47-0.94 for intakes < median and HRs: 0.71, CI: 0.53-0.93 for intakes ≥ median). Stratification based on education status resulted in reduction in the risk of MetS in participants consuming nuts ≥ median in both educated and not-educated group (HRs: 0.81, CI: 0.66-0.98 for the non-educated group and HRs: 0.63, CI: 0.47-0.84 for the educated group).

CONCLUSIONS

Incorporating nuts, especially walnuts, into dietary patterns reduced the risk of MetS, especially among individuals with more physical activity levels.

Medicinal Plants and Phytochemicals Regulating Insulin Resistance and Glucose Homeostasis in Type 2 Diabetic Patients: A Clinical Review

Diabetes is a major health problem affecting more than four hundred million adults worldwide. The transition from normal glucose tolerance to type 2 diabetes (T2D) is preceded by increased Insulin resistance (IR), an independent predictor of the development of T2D in high risk (e.g. obese populations, pre-diabetes) individuals. Insulin deficiency resulting from increased IR results in progressive glucose homeostasis dysfunction. Data has shown that IR is affected by many different factors such as genetics, age, exercise, dietary nutrients, obesity, and body fat distribution. One of the most important factors is diet, which plays an essential role in addressing T2D and metabolic syndrome. Nutraceuticals and medicinal plants have been shown to have efficacy in preventing chronic diseases like cancer, non-alcoholic fatty liver disease (NAFLD), cardiovascular disease, diabetes mellitus and metabolic syndrome, likely through the anti-inflammatory properties found in nutraceuticals. However, the effect of these compounds, including traditional plant medicines, herbal formulations or their extracts on IR have not been systematically investigated. The objective of this review was to assess the reported effects of medicinal plants and bioactive natural compounds on IR. The findings confirm that most of the herbal bioactive compounds including resveratrol, garlic, curcumin, cinnamon, ginger, nuts, berberine, anthocyanin, soybean, flaxseed, vegetable oils, and soluble fibers have benefit in their efficacy for decreasing IR, fasting blood sugar (FBS), fasting insulin and HbA1c.

Nutritional Strategies in Prediabetes: A Scoping Review of Recent Evidence

Nutritional therapy has been conventionally recommended for people with prediabetes as a method to delay or halt progression to type 2 diabetes. However, recommended nutritional strategies evolve over time. Hence, we performed a scoping review on recently reported nutritional interventions for individuals with prediabetes. Ovid MEDLINE, PubMed, Embase, Scopus, CINAHL and PsycINFO databases were searched to identify relevant research articles published within the past 10 years. Ninety-five articles involving a total of 11,211 participants were included in this review. Nutritional strategies were broadly classified into four groups: low calorie diet, low glycemic index diet, specific foods, and a combination of diet and exercise. The most frequently assessed outcomes were plasma glucose, serum insulin, serum lipid profile, body mass index and body weight. More than 50% of reported interventions resulted in significant improvements in these parameters. Nutritional interventions have demonstrated feasibility and practicality as an effective option for prediabetes management. However, the intervention variability demonstrates the challenges of a 'one-size-fits-all' approach. Investigations in genetically diverse populations and objective assessment of progression rate to diabetes are necessary to better comprehend the impact of these nutritional strategies in prediabetes.

Effects of baru almond oil (Dipteryx alata Vog.) supplementation on body composition, inflammation, oxidative stress, lipid profile, and plasma fatty acids of hemodialysis patients: A randomized, double-blind, placebo-controlled clinical trial

BACKGROUND

The consumption of nuts and edible seeds is associated with the improvement of the metabolic profile and reduction of cardiovascular diseases. However, the effects of its subproducts, such as oil, are still poorly studied. This study aimed to evaluate the effect of the baru almond oil supplementation on inflammation, oxidative stress, body composition, lipid profile, and plasma fatty acids of hemodialysis patients.

METHODS

In a randomized, double-blind, 12-week placebo-controlled clinical study, hemodialysis patients were supplemented with 5 g of baru oil (BG, n = 17) or 5 g of mineral oil (placebo, BP, n = 12). Body composition, renal function, ultra-sensitive C-reactive protein (us-CRP), oxidative stress, plasma fatty acids, and lipid profile were analysed before and after the intervention.

RESULTS

Patients were aged 50.5 ± 2.2 years and the average time of dialyses was 52,1 ± 42,6 months. The BG decreased us-CRP concentration compared to PG (-1.2 ± 0.2 vs. + 0.8 ± 0.2 mg / L,d = 0.88; p =  0.01). Baru almond oil supplementation was not effective in improving body composition, lipid profile, and oxidative stress.

CONCLUSION

Baru almond oil supplementation decreased us-CRP concentration in patients with chronic kidney disease under hemodialysis treatment.

Pistachios and cardiometabolic risk factors: A systematic review and meta-analysis of randomized controlled clinical trials

BACKGROUND

Previous experimental studies have reported that pistachios can elicit positive effects on lipid profile, blood pressure, and inflammation; however, a meta-analysis of the available evidence has yet to be performed.

OBJECTIVE

the aim of this study was to conduct systematic review and meta-analysis of the effect of pistachio enriched diets on cardiometabolic risk factors, such as weight, BMI, blood pressure, serum lipids, blood glucose, and inflammatory biomarkers.

DESIGN

A literature search was carried out for RCTs in medical databases, including PubMed/MEDLINE, Scopus, and Cochrane databases, with no time limitation up to August 2019, and conducted in accordance with the Preferred Reporting Items of Systematic Reviews and Meta-Analysis guidelines.

RESULTS

11 RCTs, with 506 participants, that reported the effect of pistachios consumption on cardiometabolic risk factors were included in this systematic review and meta-analysis. Our findings indicated that pistachios consumption significantly reduced FBS (WMD: -3.73, 95 % CI: -6.99, -0.46, I² = 99 %), TC/HDL (WMD: -0.46, 95 % CI: -0.76, -0.15, I² = 95 %), LDL/HDL (WMD: -0.24, 95 % CI: -0.38, -0.11, I² = 96 %), HbA1C (WMD: -0.14, 95 % CI: -0.26, -0.02, I² = 60 %), Insulin (WMD: -2.43, 95 % CI: -4.85, -0.001, I² = 58 %), SBP (WMD: -3.10, 95 % CI: -5.35, -0.85, I² = 63 %), and MDA (WMD: -0.36, 95 % CI: -0.49, -0.23, I² = 0%). Importantly, we did not observe adverse effects of pistachios consumption on BMI or blood pressure.

CONCLUSION

This systematic review and meta-analysis demonstrates that pistachios consumption can elicit a beneficial effect on some cardiometabolic risk factors. All previous clinical studies are well designed but some points have still remained unclear including the effects of different pistachios dosages on cardio metabolic risk factors and efficacy of pistachios consumption in preventing endothelial dysfunction. Further examination is required to determine the effect of pistachios consumption on further endothelial function risk factors.

Intake of Nuts or Nut Products Does Not Lead to Weight Gain, Independent of Dietary Substitution Instructions: A Systematic Review and Meta-Analysis of Randomized Trials

Several clinical interventions report that consuming nuts will not cause weight gain. However, it is unclear if the type of instructions provided for how to incorporate nuts into the diet impacts weight outcomes. We performed a systematic review and meta-analysis of published nut-feeding trials with and without dietary substitution instructions to determine if there are changes in body weight (BW) or composition. PubMed and Web of Science were searched through 31 December 2019 for clinical trials involving the daily consumption of nuts or nut-based snacks/meals by adults (≥18 y) for >3 wk that reported BW, BMI, waist circumference (WC), or total body fat percentage (BF%). Each study was categorized by whether or not it contained dietary substitution instructions. Within these 2 categories, an aggregated mean effect size and 95% CI was produced using a fixed-effects model. Quality of studies was assessed through the Cochrane risk-of-bias tool. Fifty-five studies were included in the meta-analysis. In studies without dietary substitution instructions, there was no change in BW [standardized mean difference (SMD): 0.01 kg; 95% CI: -0.07, 0.08; I2 = 0%] or BF% (SMD: -0.05%; 95% CI: -0.19, 0.09; I2 = 0%). In studies with dietary substitution instructions, there was no change in BW (SMD: -0.01 kg; 95% CI: -0.11, 0.09; I2 = 0%); however, there was a significant decrease in BF% (SMD: -0.32%; 95% CI: -0.61%, -0.03%; I2 = 35.4%; P < 0.05). There was no change in BMI or WC for either category of studies. Nut-enriched diet interventions did not result in changes in BW, BMI, or WC in studies either with or without substitution instructions. Slight decreases in BF% may occur if substitution instructions are used, but more research is needed. Limitations included varying methodologies between included studies and the frequency of unreported outcome variables in excluded studies.

The effectiveness of pistachio on glycemic control and insulin sensitivity in patients with type 2 diabetes, prediabetes and metabolic syndrome: A systematic review and meta-analysis

BACKGROUND AND AIMS

Pistachio nuts have been considered to improve dysglycemia. However, there are controversial results. This systematic review and meta-analysis carried out to evaluate the effects of pistachio nuts on glycemic control and insulin sensitivity in patients with type 2 diabetes mellitus (T2DM), prediabetes, and metabolic syndrome.

METHODS

Medline/PubMed, ProQuest, Web of Knowledge, Scopus, Cochrane library, and ScienceDirect were systematically searched to find randomized controlled trials (RCTs). Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) checklist was used to conduct the study.

RESULTS

Six RCTs were included in the review. Treatment with pistachio nuts exerted a significant reduction in fasting blood glucose (FBG) level (OR = 1.7, 95% CI; 1.2-2.4, P = 0.002, I² = 0.0%, P = 0.731) and homeostasis model assessment of insulin resistance (HOMA-IR) index (OR = 1.5, 95% CI; 1.0-2.4, P = 0.043, I² = 0.0%, P = 0.617), but no significant improvement was observed in regard to hemoglobin A1c (HbA1c) level (OR = 1.4, 95% CI; 0.9-2.1 P = 0.089, I² = 0.0%, P = 0.957) and fasting plasma insulin (FPI) level (OR = 1.3, 95% CI; 0.9-1.9, P = 0.133, I² = 0.0%, P = 0.776).

CONCLUSIONS

Pistachio nuts might cause a significant reduction in FBG and HOMA-IR, although HbA1c and FPI might not significantly improve in patients suffering from or at risk of T2DM.

The relationship between pistachio (Pistacia vera L) intake and adiposity: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The aim of the study was to conduct a systematic review to comprehensively evaluate the relationship between pistachio intake and obesity.

METHODS

We searched 6 databases and acquired parameters from randomized controlled trials regarding obesity, including body weight, body mass index (BMI), and waist circumference. A fixed-effect model was applied to the meta-analysis for the weighted mean difference (WMD) between a diet with pistachios and a control diet.

RESULTS

Eleven trials including a total of 1593 subjects met the inclusion criteria. Compared to the group on a control diet, the pistachio diet group showed lower BMI values (WMD: -0.18 kg/m; 95% confidence interval [CI]: -0.26, -0.11 kg/m; I = 29.8%) and no differences in body weight (WMD: -0.22 kg; 95% CI: -0.50, 0.07 kg; I = 0.0%) or waist circumference (WMD: 0.76 cm; 95% CI: -0.11, 1.63 cm; I = 7.0%).

CONCLUSION

A diet with pistachios reduced BMI and had no significant effects on body weight and waist circumference.

Effects of Pistachio Consumption in a Behavioral Weight Loss Intervention on Weight Change, Cardiometabolic Factors, and Dietary Intake

Epidemiological studies have linked regular nut consumption with lower body mass index and reduced likelihood of weight gain in adulthood. Nuts can displace other foods in the diet, and thus, promote a healthier dietary pattern. The purpose of this study was to examine the effect of pistachio nut consumption in overweight/obese adults. This randomized controlled study enrolled non-diabetic overweight/obese adults (n = 100) assigned to a 4-month behavioral weight loss intervention only group (controls) or also prescribed 1.5 oz/day (42 g/day) of pistachios (pistachio group). Outcomes were change in body weight, cardiometabolic factors, and dietary intake. Percent weight change was similar in the two groups (−5.1 [0.5] (mean [SE])% in the control group and −4.9 [0.6]% in the pistachio group, and body mass index (BMI) and waist circumference were reduced in both groups (time effect p ≤ 0.05). The pistachio group (but not the control group) exhibited a significant reduction in both systolic and diastolic blood pressure (time effect p = 0.01). Plasma alpha-carotene, beta-carotene, and lutein concentrations increased significantly in the pistachio group (time effect p < 0.05). Pistachio consumption was associated with increased dietary fiber intake and decreased consumption of sweets. Regular consumption of pistachios was associated with a comparable degree of weight loss, and similar reductions in BMI and waist circumference, in overweight/obese men and women compared to controls, and favorable changes in the diet, in the context of a behavioral weight loss intervention.

Effects of nut and seed consumption on markers of glucose metabolism in adults with prediabetes: a systematic review of randomised controlled trials

The primary aim was to investigate the effects of nut and seed consumption on markers of glucose metabolism in adults with prediabetes. Studies with a randomised controlled trial (RCT) design, comparing the effects of a diet containing nuts or seeds against a diet without nuts or seeds in adults with prediabetes, were considered eligible. Primary outcome measures included fasting plasma glucose (FPG), 2-h plasma glucose during oral glucose tolerance test and glycated Hb (HbA1c) concentrations. Studies were identified by searching PubMed and Scopus electronic databases and by checking full texts and reference lists of relevant records. Risk of bias was assessed using the Cochrane Collaboration's tool. We included five RCT involving 371 adults with prediabetes or at risk of diabetes; three RCT investigated the effects of whole nut consumption and two the effects of ground flaxseed consumption. Consumption of 57 g/d pistachios or mean intake of 60 g/d almonds for 4 months improved FPG and fasting plasma insulin (FPI) concentrations, insulin resistance, cellular glucose uptake in lymphocytes and β-cell function. Consumption of 56 g/d walnuts for 6 months was not found to affect FPG or HbA1c concentrations. Consumption of 13 g/d flaxseed for 3 months improved FPG and FPI concentrations and insulin resistance. In a second study, however, flaxseed consumption was not found to affect markers of glucose metabolism. The risk of bias was generally low, thus the reported results could be reliable. Further investigation of nut and seed consumption effects in the field of prediabetes is warranted.

Comparative effects of different types of tree nut consumption on blood lipids: a network meta-analysis of clinical trials

BACKGROUND

Recent evidence has confirmed that nuts are one of the best food groups at reducing LDL cholesterol and total cholesterol (TC). However, the comparative effects of different types of nuts on blood lipids are unclear.

OBJECTIVES

This network meta-analysis of randomized clinical trials aimed to assess the comparative effects of walnuts, pistachios, hazelnuts, cashews, and almonds on typical lipid profiles.

METHODS

We conducted literature searches to identify studies comparing ≥2 of the following diets-walnut-enriched, pistachio-enriched, hazelnut-enriched, cashew-enriched, almond-enriched, and control diets-for the management of triglycerides (TGs), LDL cholesterol, TC, and HDL cholesterol. Random-effects network meta-analyses, ranking analyses based on the surface under the cumulative ranking (SUCRA) curves, and sensitivity analyses according to the potential sources of heterogeneity across the included studies were performed for each outcome.

RESULTS

Thirty-four trials enrolling 1677 participants were included in this study. The pistachio-enriched diet was ranked best for TG (SUCRA: 85%), LDL cholesterol (SUCRA: 87%), and TC (SUCRA: 96%) reductions. For TG and TC reductions, the walnut-enriched diet was ranked as the second-best diet. Regarding LDL cholesterol reduction, the almond-enriched diet was ranked second best. The pistachio-enriched and walnut-enriched diets were more effective at lowering TG, LDL cholesterol, and TC compared with the control diet. Regarding TG and TC reductions, the pistachio-enriched diet was also more effective than the hazelnut-enriched diet. For TG reduction, the walnut-enriched diet was better than the hazelnut-enriched diet. However, these findings are limited by the low quality of evidence ratings. In addition, the quality of this network meta-analysis was limited by the small number and generally poor reporting of available studies.

CONCLUSIONS

The pistachio-enriched and walnut-enriched diet could be better alternatives for lowering TGs, LDL cholesterol, and TC compared with other nut-enriched diets included in this study. The findings warrant further evaluation by more high-quality studies.This network meta-analysis was registered at www.crd.york.ac.uk/PROSPERO as CRD42019131128.

Nut Consumption in Relation to Cardiovascular Disease Incidence and Mortality Among Patients With Diabetes Mellitus

RATIONALE

The evidence regarding the potential health benefits of nut consumption among individuals with type 2 diabetes mellitus is limited.

OBJECTIVE

To examine intake of total and specific types of nuts, including tree nuts and peanuts, in relation to subsequent risk of cardiovascular disease (CVD), including coronary heart disease and stroke, and all-cause and cause-specific mortality among individuals with diabetes mellitus.

METHODS AND RESULTS

This prospective analysis included 16 217 men and women with diabetes mellitus at baseline or diagnosed during follow-up (Nurses' Health Study: 1980-2014, Health Professionals Follow-Up Study: 1986-2014). Nut consumption was assessed using a validated food frequency questionnaire and updated every 2 to 4 years. During 223 682 and 254 923 person-years of follow-up, there were 3336 incident CVD cases and 5682 deaths, respectively. Higher total nut consumption was associated with a lower risk of CVD incidence and mortality. The multivariate-adjusted hazard ratios (95% CIs) for participants who consumed 5 or more servings of total nuts per week (1 serving=28 g), compared with those who consumed <1 serving per month, were 0.83 (0.71-0.98; P trend=0.01) for total CVD incidence, 0.80 (0.67-0.96; P trend=0.005) for coronary heart disease incidence, 0.66 (0.52-0.84; P trend <0.001) for CVD mortality, and 0.69 (0.61-0.77; P trend <0.001) for all-cause mortality. Total nut consumption was not significantly associated with risk of stroke incidence or cancer mortality. For specific types of nuts, higher tree nut consumption was associated with lower risk of total CVD, coronary heart disease incidence, and mortality because of CVD, cancer, and all causes, whereas peanut consumption was associated with lower all-cause mortality only (all P trend <0.001). In addition, compared with participants who did not change the consumption of total nuts from pre- to post-diabetes mellitus diagnosis, participants who increased consumption of total nuts after diabetes mellitus diagnosis had an 11% lower risk of CVD, a 15% lower coronary heart disease risk, a 25% lower CVD mortality, and a 27% lower all-cause mortality. The associations persisted in subgroup analyses stratified by sex/cohort, body mass index at diabetes mellitus diagnosis, smoking status, diabetes mellitus duration, nut consumption before diabetes mellitus diagnosis, or diet quality.

CONCLUSIONS

Higher consumption of nuts, especially tree nuts, is associated with lower CVD incidence and mortality among participants with diabetes mellitus. These data provide novel evidence that supports the recommendation of incorporating nuts into healthy dietary patterns for the prevention of CVD complications and premature deaths among individuals with diabetes mellitus.

Acute Effect of Pistachio Intake on Postprandial Glycemic and Gut Hormone Responses in Women With Gestational Diabetes or Gestational Impaired Glucose Tolerance: A Randomized, Controlled, Crossover Study

Long-term consumption of pistachios could potentially improves glucose homeostasis. Impaired postprandial glucose, insulin, and glucagon-like peptide-1 (GLP-1) responses have been reported in gestational diabetes mellitus (GDM) patients. The objective of this study was to evaluate the acute effects of two isocaloric test meals, 42 g pistachios and 100 g whole-wheat bread (WWB) on postprandial glucose, insulin, and gut derived incretin levels in Chinese women with gestational impaired glucose tolerance (GIGT) or GDM. Expected glucose and insulin responses were observed after WWB consumption. Isocaloric pistachio intake had minimal effect on blood glucose or insulin. In both GIGT and GDM patients, significant higher GLP-1 levels were observed at 90 and 120 min after pistachio compared to WWB intake. Significant lower gastric inhibitory polypeptide (GIP) levels were observed at 30 and 60 min in GDM patients or 120 min in GIGT patients after pistachio compared to WWB intake. In summary, isocaloric pistachio intake induced significantly lower postprandial glucose, insulin and GIP but higher GLP-1 levels compared to WWB. Our data suggest pistachios are effective alternative to a low-fat, high-carbohydrate food to improve postprandial glucose, insulin, and GLP-1 response in women with GDM and GIGT.