Effects of walnut consumption on blood lipids and other cardiovascular risk factors: an updated meta-analysis and systematic review of controlled trials

Impact of walnut consumption on glycemic control and anthropometric indices: a systematic review and meta-analysis of randomized controlled trials

Objectives

Previous studies have led to conflicting results regarding the effect of walnut consumption on glycemic control, and anthropometric indices. This study aimed to evaluate the efficacy of walnut consumption on serum levels of fasting blood sugar (FBS), fasting insulin, hemoglobin A1C (HbA1c), homeostasis model assessment of insulin resistance (HOMA-IR), weight and body mass index (BMI) through a systematic review and meta-analysis of randomized controlled trials (RCTs).

Methods

PubMed, Scopus, Web of Science, and the Cochrane databases were searched up to February 2023. Weighted mean difference (WMD) was analyzed using random effects models to assess the overall effect.

Results

A total of thirty-two RCTs were included in the systematic review and meta-analysis. Walnut supplementation was found to significantly reduce HOMA-IR (WMD = -0.29; 95% CI: -0.57, -0.01, P = 0.04), and body weight (WMD = -0.14 kg; 95% CI: -0.24, -0.04; P = 0.008). However, the meta-analysis showed that walnut supplementation did not have a significant effect on FBS (WMD = 0.62 mg/dL; 95% CI: -0.66, 1.91; P = 0.34), insulin levels (WMD = 1.27 mIU/ml; 95% CI: -0.59, 3.14; P = 0.18), HbA1C (WMD = 0.00%; 95% CI: -0.09, 0.10; P = 0.95), and BMI (WMD = -0.10 kg/m2; 95% CI: -0.40, 0.20; P = 0.50).

Conclusion

In conclusion, this study found a significant reduction in HOMA-IR levels and body weight with walnut supplementation, while other glycemic markers, and obesity-related indices did not change significantly. Future well-designed trials are needed to confirm these results.

Effect of nut consumption on blood lipids: An updated systematic review and meta-analysis of randomized controlled trials

AIMS

Nuts are nutrient-dense foods touted for their health-promoting effects, especially regarding cardiovascular health, yet inconsistencies in the literature remain in relation to their effect on blood lipids. Hence, a systematic review and meta-analysis of randomized controlled trials (RCTs) was conducted to determine the effect of nut intake on blood lipids.

DATA SYNTHESIS

MEDLINE-PubMed and Cochrane databases were searched. 113 unique trials met eligibility criteria (n = 8060 adults with various health status) assessing the effect of a median daily dose of 45.5 g/d of nuts compared to a non-nut control on blood lipid outcomes met inclusion criteria. Overall, nut consumption resulted in moderate reductions in total cholesterol (mean difference, -0.14 mmol/L [95 % confidence interval, -0.18 to -0.10 mmol/L]) and LDL-C (-0.12 mmol/L [-0.14 to -0.09 mmol/L]), with small reductions in triglycerides (-0.05 mmol/L [-0.07 to -0.03 mmol/L]), TC:HDL-C (-0.11 [-0.16 to -0.06]), LDL-C:HDL-C (-0.19 [-0.24 to -0.12]), and apolipoprotein B (-0.04 g/L [-0.06 to -0.02 g/L]). There was no significant impact on HDL-cholesterol or other assessed measures. Certainty of evidence was high for apolipoprotein A, and generally moderate/low for all other outcomes. Sensitivity analysis did not change the evidence on the main outcomes. Significant effect modifications in subgroup analysis were shown for most of the lipid parameters assessed. None of these subgroup effects altered the evidence of heterogeneity for any primary outcome.

CONCLUSIONS

Current evidence provides a good indication that consuming nuts may advantageously affect blood lipids in adults with a mix of health status.

PROSPERO REGISTRATION

PROSPERO identifier, CRD42022358688.

Effect of Nuts on Anthropometric and Glycemic Indexes and Blood Pressure in Secondary Cardiovascular Prevention: A Systematic Review and Meta-analysis of Randomized Controlled Trials

CONTEXT

Nut-enriched diets have a positive impact on cardiovascular risk factors, such as body mass, blood pressure, and fasting blood glucose. However, studies in individuals undergoing secondary cardiovascular prevention show controversial results.

OBJECTIVE

This systematic review with meta-analysis assessed the effect of nut supplementation on anthropometric, glycemic, and blood pressure indices in patients with atherosclerotic cardiovascular disease, as well as the frequency of adverse events.

DATA SOURCES

Six databases were used for the search-PubMed, Cochrane Library, EMBASE, BVS (Biblioteca Virtual da Saude), Web of Science, and ClinicalTrials.gov-until February 2023, with no language restrictions.

DATA EXTRACTION

The Cochrane Handbook for Systematic Reviews of Interventions methodology and the PICOS (Population, Intervention, Comparison, Outcome, Setting/design) strategy were used. Seven independent reviewers were involved in data extraction and resolution of disagreements. Certainty of the evidence was evaluated using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) system.

DATA ANALYSIS

From 5187 records identified, 6 publications containing data referring to 5 randomized clinical trials (n = 436) were included in the final analyses. The nuts evaluated were almonds, pecans, Brazil nuts, and mixed nuts, with portions that varied between 5 g and 85 g (median: 30 g/day). The intervention period varied between 6 and 12 weeks. The nuts had no effect on fasting glucose and anthropometric indices, although the certainty of the evidence for most of these outcomes was low or very low. They also had no effect on systolic (mean difference [MD]: -1.16 mmHg [95% CI, -5.68 to 3.35], I2 = 0%-moderate certainty of evidence) or diastolic (MD: 0.10 mmHg [95% CI, -2.30 to 2.51], I2 = 0%-high certainty of evidence) blood pressure. It was not possible to aggregate data on adverse events.

CONCLUSION

Nut supplementation had no effect on blood pressure, fasting glucose, or anthropometric profile in the context of atherosclerotic cardiovascular disease.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42020163456.

Mediators of the association between nut consumption and cardiovascular diseases: a two-step mendelian randomization study

Previous observational studies have reported inconsistent associations between nut consumption and cardiovascular diseases (CVD). This study aims to identify the causal relationship between different types of nuts consumption and CVD, and to quantify the potential mediating effects of cardiometabolic factors. We utilized Genome-Wide Association Study (GWAS) data to assess the causal effects of nut consumption on CVD using two-sample Mendelian randomization (MR) and a two-step MR analysis. The inverse variance weighted (IVW) method indicated that processed (salted or roasted) peanuts were potentially and positively associated with ischaemic heart disease (IHD) (OR 1.4866; 95%CI 1.0491-2.1065). No causal relationships were found between nuts consumption and other CVD outcomes, including atrial fibrillation, angina, coronary atherosclerosis, coronary heart disease, IHD, myocardial infarction, subarachnoid hemorrhage, intracerebral haemorrhage and stroke. Both MR-Egger and median-based methods yielded similar results to IVW. Furthermore, in the two-step MR analysis, fasting insulin, low-density lipoprotein cholesterol and fasting blood glucose were identified as mediators in the potential causal relationship between processed peanuts and IHD, explaining 16.98%, 6.38% and 4.91% of the mediation, respectively. In total, these mediators accounted for 28.27% of the association between salted or roasted peanuts and IHD.

Effects of walnut kernel pellicle on the composition and properties of enzymatic hydrolysates of walnut meal by peptidomics and bioinformatics

The purpose of this article is to investigate the effects of walnut (Juglans regia L.) kernel pellicle on the composition and properties of enzymatic hydrolysis products of walnut meal using peptidomics and bioinformatics. In this study, a total of 3423 peptide sequences were identified in peeled walnut protein hydrolysates (PWPH) and unpeeled walnut protein hydrolysates (UWPH). Due to the presence of the walnut kernel pellicle, the enzyme cleavage sites of alkaline proteases on walnut precursor proteins were altered, resulting in differences in the number and length of the peptides obtained. Principal component analysis indicates significant differences between PWPH and UWPH. Combined with bioinformatics analysis, it was shown that walnut kernel peeling improved the release of peptides, formed more bioactive peptides, reduced allergenicity, and improved water solubility. Seven peptides with acetylcholinesterase (AChE) inhibitory activity were identified, and the peptide Val-Gly-Ala-Pro-Phe-Asp-Gly-Ala (VGAPFDGA) has the strongest inhibitory activity with an IC50 of 0.38 ± 0.01 mg/mL. These results confirmed that walnut kernel peeling could greatly change the composition of the walnut protein hydrolysates, and seven novel peptides were reported that showed significant AChE inhibitory activity.

Unlocking the Cardiovascular Benefits of Walnuts: Insights on Molecular Mechanism From Animal Studies

The health-promoting benefits of walnut consumption are substantially ascribed to its fatty acid (FA) profile, which is rich in polyunsaturated FA with an exceptionally high n-3 to n-6 ratio. There are also phytonutrients in walnuts that are linked to health welfare. This review article integrates all studies on the effects of walnuts on the cardiovascular system performed on experimental animals, and thus is a source of data on the mechanisms underlying the observed effects. These studies, which are very diverse in experimental design, indicate that a diet enriched with walnuts or treating animals with walnut extract or chemical constituents of walnuts, has many favorable effects on heart and vascular system function. The cardiovascular effect of walnuts depends on the metabolic status of the organism. Among the cardiovascular effects of walnuts is that they improve the FA profile in the circulation and heart in favor of n-3 polyunsaturated FAs. In addition, a favorable effect on triglyceride and cholesterol status, which reduces cardiovascular disease risk, is observed. Intake of walnuts promotes FA catabolism and has anti-inflammatory, antioxidant, and antiarrhythmic effects. Walnuts also have a beneficial effect on vascular tone, accompanied by a decrease in blood pressure and reduced risk for atherosclerosis. In conclusion, studies on experimental animals encourage the consumption of walnuts as a simple, convenient approach to improve cardiovascular health.

Protein Consumption and Risk of CVD Among U.S. Adults: The Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND

Although some randomized trials have reported beneficial effects of protein intake on cardiometabolic risk factors, evidence from prospective studies have not supported a strong link between protein intake and cardiovascular disease (CVD) risk. It is also unclear whether diversity in protein intake plays a role in CVD risk.

OBJECTIVE

We investigated prospective associations of (1) protein intake, overall and by food source and (2) diversity of protein sources with risk of CVD, coronary heart disease (CHD), and stroke.

METHODS

In a multi-ethnic cohort of 5879 U.S. adults (45-84 years), who were free of CVD at baseline, protein intake was assessed at baseline (2000-2002) using a validated 120-item food frequency questionnaire. Two different aspects of protein diversity were assessed including count (number of protein food consumed at least once/week) and dissimilarity (diversity of the attributes of the protein sources consumed). Relationships with incident CVD outcomes through 2019 were assessed using Cox proportional hazards models adjusting for sociodemographic, lifestyle, and comorbidity factors.

RESULTS

During 83,430 person-years, 1045 CVD cases were identified, including 668 CHD and 332 stroke cases. In multivariable models, we found no significant associations between protein intake, overall and by food source, with incident CVD, CHD, or stroke. Protein count, but not protein dissimilarity, was weakly associated with CVD risk. We found no significant associations between diversity of consumption of animal or plant food source and CVD outcomes.

CONCLUSIONS

Our findings suggest protein consumption may not significantly impact CVD risk in middle-aged adults.

Diet Quality and Epigenetic Aging in the Women's Health Initiative

BACKGROUND

Higher diet quality scores are associated with a lower risk for many chronic diseases and all-cause mortality; however, it is unclear if diet quality is associated with aging biology.

OBJECTIVE

This study aimed to examine the association between diet quality and a measure of biological aging known as epigenetic aging.

DESIGN

A cross-sectional data analysis was used to examine the association between three diet quality scores based on self-reported food frequency questionnaire data and five measures of epigenetic aging based on DNA methylation (DNAm) data from peripheral blood.

PARTICIPANTS/SETTING

This study included 4,500 postmenopausal women recruited from multiple sites across the United States (1993-98), aged 50 to 79 years, with food frequency questionnaire and DNAm data available from the Women's Health Initiative baseline visit.

MAIN OUTCOME MEASURES

Five established epigenetic aging measures were generated from HumanMethylation450 Beadchip DNAm data, including AgeAccelHannum, AgeAccelHorvath, AgeAccelPheno, AgeAccelGrim, and DunedinPACE.

STATISTICAL ANALYSES PERFORMED

Linear mixed models were used to test for associations between three diet quality scores (Healthy Eating Index, Dietary Approaches to Stop Hypertension, and alternate Mediterranean diet scores) and epigenetic aging measures, adjusted for age, race and ethnicity, education, tobacco smoking, physical activity, Women's Health Initiative substudy from which DNAm data were obtained, and DNAm-based estimates of leukocyte proportions.

RESULTS

Healthy Eating Index, Dietary Approaches to Stop Hypertension, and alternate Mediterranean diet scores were all inversely associated with AgeAccelPheno, AgeAccelGrim, and DunedinPACE (P < 0.05), with the largest effects with DunedinPACE. A one standard deviation increment in diet quality scores was associated with a decrement (β ± SE) in DunedinPACE z score of -0.097 ± 0.014 (P = 9.70 x 10-13) for Healthy Eating Index, -0.107 ± 0.014 (P = 1.53 x 10-14) for Dietary Approaches to Stop Hypertension, and -0.068 ± 0.013 (P = 2.31 x 10-07) for the alternate Mediterranean diet.

CONCLUSIONS

In postmenopausal women, diet quality scores were inversely associated with DNAm-based measures of biological aging, particularly DunedinPACE.

Effects of mixed nuts as part of a Brazilian Cardioprotective diet on LDL-cholesterol in adult patients after myocardial infarction: a multicenter randomized controlled clinical trial

BACKGROUND

Nuts consumption is related to cardioprotective effects on primary cardiovascular prevention, but studies conducted in secondary prevention are small, scarce and controversial. The objective of this trial was to evaluate the effects of a regional and sustainable cardioprotective diet added or not with an affordable mixed nuts on cardiometabolic features in patients with previous myocardial infarction.

METHODS

DICA-NUTS study is a national, multi-center, and superiority-parallel randomized clinical trial. Males and females over 40 years old diagnosed with previous myocardial infarction in the last 2 to 6 months were included. Patients were allocated into two groups: the Brazilian Cardioprotective diet (DICA Br) supplemented with 30 g/day of mixed nuts (10 g of peanuts; 10 g of cashew; 10 g of Brazil nuts) (intervention group, n = 193); or only DICA Br prescription (control group, n = 195). The primary outcome was low-density lipoprotein cholesterol means (in mg/dL) after 16 weeks. Secondary outcomes were other lipid biomarkers, glycemic and anthropometric data and diet quality.

RESULTS

After adjustment for baseline values, participating study site, time since myocardial infarction and statin treatment regimen (high potency, moderate and low potency/no statins), no significant difference was found between the groups in low-density lipoprotein cholesterol concentrations (intervention-control difference: 3.48 mg/dL [-3.45 to 10.41], P = 0.32). Both groups improved their overall diet quality at the end of the study without differences between them after 16 weeks (intervention-control difference: 1.05 (-0.9 to 2.99); P = 0.29). Other lipids, glycemic profile and anthropometrics were also not different between study groups at the end of the study.

CONCLUSION

Adding 30 g/day of mixed nuts to the DICA Br for 16 weeks did not change lipid, glycemic and anthropometric features in the post-myocardial infarction setting.

TRIAL REGISTRATION

This study is registered on ClinicalTrials.gov website under number NCT03728127 and its World Health Organization Universal Trial Number (WHO-UTN) is U1111-1259-8105.

Effect of nuts on lipid profile and inflammatory biomarkers in atherosclerotic cardiovascular disease: a systematic review and meta-analysis of randomized controlled trials

PURPOSE

Nut-enriched diets are related to improve lipid and inflammatory biomarkers in meta-analyses in the context of primary cardiovascular prevention. However, primary studies on secondary cardiovascular prevention are scarce and controversial. This systematic review and meta-analysis aimed to evaluate the effect of nut supplementation on lipid and inflammatory profiles in individuals with atherosclerotic cardiovascular disease, and the frequency of adverse events.

METHODS

Six databases were used for research: PubMed, EMBASE, BVS, Cochrane Library, Web of Science, and ClinicalTrials.gov, until February 2023, with no language restrictions. We performed random-effects meta-analyses to compare nut-enriched diets vs. control diets for pre-post intervention changes. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system assessed the evidence's certainty.

RESULTS

From the 5187 records identified, eight publications containing data referring to five randomized clinical trials involving 439 participants were included in the final analyses. The nuts evaluated were almonds, pecans, Brazil nuts, and mixed nuts, with doses ranging between 5 g and 85 g (median: 30 g/day). The intervention time varied between 6 and 12 weeks. Compared to nut-free diets, nut intake did not have a statistically significant effect on lipid profile biomarkers, except on the atherogenic index (MD: -0.32 [95% CI -0.58 to -0.06], I2 = 0% - moderate certainty of the evidence). Similarly, there was no effect of nuts on inflammatory profile biomarkers. It was not possible to aggregate data on adverse events.

CONCLUSIONS

Nut supplementation did not change lipid and inflammatory profiles in the secondary cardiovascular prevention setting.

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.

Effect of a Higher-Protein Nut versus Higher-Carbohydrate Cereal Enriched Diet on the Gut Microbiomes of Chinese Participants with Overweight and Normoglycaemia or Prediabetes in the Tū Ora Study

Global increases in metabolic disorders such as type 2 diabetes (T2D), especially within Asian populations, highlight the need for novel approaches to dietary intervention. The Tū Ora study previously evaluated the effects on metabolic health of including a nut product into the diet of a New Zealand cohort of Chinese participants with overweight and normoglycaemia or prediabetes through a 12-week randomised, parallel-group clinical trial. In this current study, we compared the impact of this higher-protein nut bar (HP-NB) versus a higher-carbohydrate cereal bar (HC-CB) on the faecal microbiome by employing both 16S rRNA gene amplicon and shotgun metagenomic sequencing of pre- and post-intervention pairs from 84 participants. Despite the higher fibre, protein, and unsaturated fat content of nuts, there was little difference between dietary groups in gut microbiome composition or functional potential, with the bacterial phylum Firmicutes dominating irrespective of diet. The lack of observed change suggests the dietary impact of the bars may have been insufficient to affect the gut microbiome. Manipulating the interplay between the diet, microbiome, and metabolic health may require a more substantial and/or prolonged dietary perturbation to generate an impactful modification of the gut ecosystem and its functional potential to aid in T2D risk reduction.

Current Insights into the Effects of Dietary α-Linolenic Acid Focusing on Alterations of Polyunsaturated Fatty Acid Profiles in Metabolic Syndrome

The plant-derived α-linolenic acid (ALA) is an essential n-3 acid highly susceptible to oxidation, present in oils of flaxseeds, walnuts, canola, perilla, soy, and chia. After ingestion, it can be incorporated in to body lipid pools (particularly triglycerides and phospholipid membranes), and then endogenously metabolized through desaturation, elongation, and peroxisome oxidation to eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), with a very limited efficiency (particularly for DHA), beta-oxidized as an energy source, or directly metabolized to C18-oxilipins. At this moment, data in the literature about the effects of ALA supplementation on metabolic syndrome (MetS) in humans are inconsistent, indicating no effects or some positive effects on all MetS components (abdominal obesity, dyslipidemia, impaired insulin sensitivity and glucoregulation, blood pressure, and liver steatosis). The major effects of ALA on MetS seem to be through its conversion to more potent EPA and DHA, the impact on the n-3/n-6 ratio, and the consecutive effects on the formation of oxylipins and endocannabinoids, inflammation, insulin sensitivity, and insulin secretion, as well as adipocyte and hepatocytes function. It is important to distinguish the direct effects of ALA from the effects of EPA and DHA metabolites. This review summarizes the most recent findings on this topic and discusses the possible mechanisms.

Nuts and seeds - a scoping review for Nordic Nutrition Recommendations 2023

Background

Nuts and seeds have been part of diets in most of the world for millenniums, and they have also been consumed in the Nordic and Baltic countries for centuries. Consumption of nuts and seeds is linked with various health outcomes. Therefore, when updating the Nordic Nutrition Recommendations (NNR), summarizing the best evidence on key health outcomes from the consumption of nuts and seeds is essential.

Objectives

This study aims to evaluate the updated evidence on the consumption of nuts and seeds and health outcomes regarded relevant for the Nordic and Baltic countries, as well as their dose-response relationship presented in updated systematic reviews and meta-analyses.

Method

The scoping review is built on a de novo systematic review and an umbrella review published in 2022 on the consumption of nuts and seeds and its various health outcomes, including cardiovascular disease and diabetes.

Results

Intake of nuts and seeds is associated with a lower risk of cardiovascular diseases, with evidence assessed as probable. This conclusion is mirrored by evidence from trials on biomarkers for chronic diseases. An intake of a serving of nuts of 28-30 g/day compared to not eating nuts is estimated to translate into approximately 20% relative reduction in the risks of cardiovascular disease and premature deaths. For cancers, consumption of a serving of nuts is inversely associated with cancer mortality. However, for type 2 diabetes, there are mixed and inconclusive results. Additionally, there are inverse associations between nut consumption and respiratory and infectious disease mortality. Allergies for nuts are seen among 1-2% of the population.

Conclusion

Overall, the current evidence supports dietary recommendations to increase nut consumption to a serving of nuts and seeds per day for people without allergies to these foods.

Lifestyle and Lipoprotein(a) Levels: Does a Specific Counseling Make Sense?

Lipoprotein(Lp)(a) is a variant of low-density lipoprotein (LDL), bound to apolipoprotein B100, whose levels are associated with a significant increase in the risk of atherosclerosis-related cardiovascular events, but also to aortic stenosis and atrial fibrillation. Since plasma levels of Lp(a) are commonly considered resistant to lifestyle changes, we critically reviewed the available evidence on the effect of weight loss, dietary supplements, and physical activity on this risk factor. In our review, we observed that relevant body weight loss, a relatively high intake of saturated fatty acids, the consumption of red wine, and intense physical exercise seems to be associated with significantly lower plasma Lp(a) levels. On the contrary, foods rich in trans-unsaturated fatty acids are associated with increased Lp(a) levels. With regard to dietary supplements, coenzyme Q10, L-Carnitine, and flaxseed exert a mild but significant lowering effect on plasma Lp(a).

Important roles of linoleic acid and α-linolenic acid in regulating cognitive impairment and neuropsychiatric issues in metabolic-related dementia

Metabolic syndrome (MetS), which is characterized by insulin resistance, high blood glucose, obesity, and dyslipidemia, is known to increase the risk of dementia accompanied by memory loss and depression. The direct pathways and specific mechanisms in the central nervous system (CNS) for addressing fatty acid imbalances in MetS have not yet been fully elucidated. Among polyunsaturated acids, linoleic acid (LA, n6-PUFA) and α-linolenic acid (ALA, n3-PUFA), which are two essential fatty acids that should be provided by food sources (e.g., vegetable oils and seeds), have been reported to regulate various cellular mechanisms including apoptosis, inflammatory responses, mitochondrial biogenesis, and insulin signaling. Furthermore, inadequate intake of LA and ALA is reported to be involved in neuropathology and neuropsychiatric diseases as well as imbalanced metabolic conditions. Herein, we review the roles of LA and ALA on metabolic-related dementia focusing on insulin resistance, dyslipidemia, synaptic plasticity, cognitive function, and neuropsychiatric issues. This review suggests that LA and ALA are important fatty acids for concurrent treatment of both MetS and neurological problems.

The Cardioprotective Properties of Selected Nuts: Their Functional Ingredients and Molecular Mechanisms

Nuts have been known as a nutritious food since ancient times and can be considered part of our original diet: they are one of the few foods that have been eaten in the same form for thousands of years. They consist of various dry fruits and seeds, with the most common species being almonds (Prunus dulcis), hazelnuts (Corylus avellana), cashews (cashew nuts, Anacardium occidentale), pistachios (Pistacia vera), walnuts (Italian nuts, Juglans regia), peanuts (Arachia hypogaca), Brazil nuts (Bartholletia excels), pecans (Corya illinoinensis), macadamia nuts (Macademia ternifolia) and pine nuts. Both in vitro and in vivo studies have found nuts to possess a range of bioactive compounds with cardioprotective properties, and hence, their consumption may play a role in preventing and treating cardiovascular diseases (CVDs). The present work reviews the current state of knowledge regarding the functional ingredients of various nuts (almonds, Brazil nuts, cashew nuts, hazelnuts, macadamia nuts, peanuts, pecan nuts, pine nuts, pistachios, and walnuts) and the molecular mechanisms of their cardioprotective action. The data indicate that almonds, walnuts and pistachios are the best nut sources of bioactive ingredients with cardioprotective properties.

Can different types of tree nuts and peanuts induce varied effects on specific blood lipid parameters? A systematic review and network meta-analysis

Tree nuts and peanuts have shown cardioprotective effects through the modulation of blood lipid levels. Despite the abundance of scientific evidence available, it remains uncertain whether the type of nut consumed influences these changes. The objective of this study was to evaluate and rank the effects of six types of nuts on total cholesterol (total-c), low-density lipoprotein (LDL-c), triglyceride (TG) and high-density lipoprotein (HDL-c) levels through a systematic search of randomized controlled trials (RCTs), a frequentist network meta-analysis (NMA), and the estimation of SUCRA values. A total of 76 RCTs were ultimately analyzed. The total c for pistachios, almond, and walnuts; LDL-c for cashews, walnuts, and almond; and TG for hazelnuts and walnuts significantly decreased, while only peanuts exhibited a significant increase in HDL-c levels. According to the rankings, the most effective type of nut for reducing total cholesterol was pistachio, cashew for LDL-c, hazelnut for TG, and peanut for increasing HDL-c levels. It should be noted that every type of nut analyzed exhibited a significant positive impact on some parameters, and specific types demonstrated enhanced advantages for particular blood lipids. These results endorse the use of personalized nutritional strategies to address and prevent dyslipidemia.Registration: PROSPERO database CRD42021270779.

Effects of Walnut-Rich Diet on Cation-Handling Proteins in the Heart of Healthy and Metabolically Compromised Male Rats

The transport of cations in the cardiomyocytes, crucial for the functioning of the heart, can be affected by walnut diet due to the high content of polyunsaturated fatty acids. Healthy and metabolically compromised rats (drinking 10% fructose solution) were subjected to a diet supplemented with 2.4 g of walnuts for 6 weeks to investigate the effect on proteins involved in cation transport in the heart cells. Fructose increased the level of the α1 subunit of Na+/K+-ATPase and the phosphorylation of extracellular signal-regulated kinase 1/2 in the heart of control and walnut-eating rats, while elevated L-type calcium channel α (LTCCα), sodium-calcium exchanger 1 (NCX1), and Maxi Kα level were observed only in rats that did not consume walnuts. However, walnuts significantly increased the cardiac content of LTCC, NCX1, and Maxi Kα, as well as Kir6.1 and SUR2B subunits of KATP channel, but only in fructose-naive rats. In animals that drank fructose, a significant increasing effect of walnuts was observed only in Akt kinase phosphorylation, which may be a part of the antiarrhythmic mechanism of decreasing cation currents in cardiomyocytes. The walnut diet-induced increase in LTCC and NCX1 expression in healthy rats may indicate intense cardiac calcium turnover, whereas the effect on Kir6.1 and SUR2B subunits suggests stimulation of KATP channel transport in the cardiac vasculature. The effects of walnuts on the cation-handling proteins in the heart, mostly limited to healthy animals, suggest the possible use of a walnut-supplemented diet in the prevention rather than the treatment of cardiological channelopathies.

Walnut consumption and gut microbial metabolism: Results of an exploratory analysis from a randomized, crossover, controlled-feeding study

BACKGROUND & AIMS

The effect of walnut-related modulation of gut microbiota composition on microbiota functionality is unknown. The aim was to characterize the effect of a walnut-enriched diet (WD), compared to a fatty acid-matched diet devoid of walnuts (WFMD) and a diet where oleic acid replaces alpha-linolenic acid (ORAD), on bacterial gene expression.

METHODS

A 3-period, randomized, crossover, controlled-feeding study was conducted. Participants were provided a 2-week run-in standard western diet (SWD; 50% kcal carbohydrate, 16% protein, 34% fat, 12% SFA). Following the SWD in random sequence order, participants were provided the WD, WFMD, and ORAD (48% carbohydrate; 17% protein; fat 35%; 7% SFA). The WD contained 18% of energy from walnuts (57 g/d/2100 kcal). The WFMD and ORAD were devoid of walnuts; liquid non-tropical plant oils were included in these diets. Metatranscriptomic analyses were performed as an exploratory outcome.

RESULTS

The analytical sample included 35 participants (40% female) with a mean ± SD age of 43 ± 10 y and BMI of 30.3 ± 4.9 kg/m2. The ⍺-diversity of taxa actively expressing genes, assessed by observed species (p = 0.27) and Pielou's Evenness (p = 0.09), did not differ among the diets. The ⍺-diversity of actively expressed genes was greater following the WD compared to the WFMD and ORAD as assessed by the observed genes and Pielou's Evenness metrics (p < 0.05). β-Diversity of the actively expressed genes differed following the WD compared to the WFMD (p = 0.001) and ORAD (p = 0.001); β-diversity did not differ between the WFMD and ORAD. Active composition analyses showed increased Gordonibacter (p < 0.001) activity following the WD vs. the ORAD. Greater expression of many genes was observed following the WD compared to the WFMD and ORAD. Following the WD, greater expression of metabolism-related genes encoding glycine amidinotransferase (GATM; K00613) and arginine deiminase (K01478) was observed compared to the WFMD. Greater expression of glycine amidinotransferase (GATM; K00613) by Gordonibacter was also observed following the WD vs. the WFMD and ORAD.

CONCLUSION

Our results suggest walnut intake may increase endogenous production of homoarginine through gut microbiota-mediated upregulation of GATM, which is a novel mechanism by which walnuts may lower cardiovascular disease risk. However, given the exploratory nature replication is needed.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov (NCT02210767).

Diet composition influences the effect of high fat diets on bone in growing male mice

The effect of diet-induced obesity on bone in rodents is variable, with bone mass increases, decreases, and no impact reported. The goal of this study was to evaluate whether the composition of obesogenic diet may influence bone independent of its effect on body weight. As proof-of-principle, we used a mouse model to compare the skeletal effects of a commonly used high fat 'Western' diet and a modified high fat diet. The modified high fat diet included ground English walnut and was isocaloric for macronutrients, but differed in fatty acid composition and contained nutrients (e.g. polyphenols) not present in the standard 'Western' diet. Eight-week-old mice were randomized into 1 of 3 dietary treatments (n = 8/group): (1) low fat control diet (LF; 10 % kcal fat); (2) high fat 'Western' diet (HF; 46 % kcal fat as soybean oil and lard); or (3) modified high fat diet supplemented with ground walnuts (HF + walnut; 46 % kcal fat as soybean oil, lard, and walnut) and maintained on their respective diets for 9 weeks. Bone response in femur was then evaluated using dual energy x-ray absorptiometry, microcomputed tomography, and histomorphometry. Consumption of both obesogenic diets resulted in increased weight gain but differed in impact on bone and bone marrow adiposity in distal femur metaphysis. Mice consuming the high fat 'Western' diet exhibited a tendency for lower cancellous bone volume fraction and connectivity density, and had lower osteoblast-lined bone perimeter (an index of bone formation) and higher bone marrow adiposity than low fat controls. Mice fed the modified high fat diet did not differ from mice fed control (low fat) diet in cancellous bone microarchitecture, or osteoblast-lined bone perimeter, and exhibited lower bone marrow adiposity compared to mice fed the 'Western' diet. This proof-of-principal study demonstrates that two obesogenic diets, similar in macronutrient distribution and induction of weight gain, can have different effects on cancellous bone in distal femur metaphysis. Because the composition of the diets used to induce obesity in rodents does not recapitulate a common human diet, our finding challenges the translatability of rodent studies evaluating the impact of diet-induced obesity on bone.

A Dietary Model of Partial Meat Replacement with Walnuts Demonstrates Changes in the Nutrient Profile and Quality of the United States Population's Diet

The purpose of the study is to assess the impact of partial meat replacement with walnuts using a dose-escalation approach on nutrient intake and diet quality in the usual US diet. Food modeling was implemented using the nationally representative 2015-2018 National Health and Examination Survey (NHANES), with a focus on non-nut consumers, which included 2707 children and adolescents and 5190 adults. Walnuts replaced meat in a dose-escalating manner (0.5, 1, 1.5, and 2 oz walnuts per day replaced 1, 2, 3, and 4 oz meat, respectively). Diet quality was estimated using the population ratio method of the 2015 Healthy Eating Index. The usual intake of nutrients was estimated using the National Cancer Institute method. Significant differences were determined using non-overlapping 95% confidence intervals. The partial replacement of meat with walnuts demonstrated significant increases in the mean intake of fiber, magnesium, and omega-3 fatty acids and significant decreases in cholesterol and vitamin B12 in the modeled diets for children, adolescents, and adults. Additionally, the partial replacement of meat with walnuts improved overall diet quality. Walnut consumption at 1-2 oz as a replacement for some meat may improve nutrient intake and diet quality across age groups.

Enhanced Elderberry Snack Bars: A Sensory, Nutritional, and Rheological Evaluation

Interest in functional foods is continuously increasing, having the potential to be an ally in reducing cardiometabolic risk factors. This study focuses on developing and evaluating oat- and millet-based snack bars enriched with freeze-dried elderberry powder (FDEBP), aiming to combine great taste with enhanced nutritional value, antioxidant properties, and prebiotic potential. The research encompassed a sensory evaluation, nutritional assessment, and rheological analysis of the snack bars. A hedonic test was conducted to gauge consumer preferences and overall liking, providing insights into taste, texture, and acceptance. Sensory evaluation revealed positive feedback from participants, and acceptance rating scores ranged from 7 to 8.04, the best score recorded by one of the enhanced bars with 1% FDEBP. The rheological analysis determined the bars' dynamic storage modulus (G') and loss modulus (G″), assessing the material's elasticity and mechanical properties. Results showed that the incorporation of 0.5% and 1% FDEBP in the oat and millet snack bars significantly impacted their rheological properties, enhancing structural strength. Nutritional analysis demonstrated that the snack bars provided a complete mix of macronutrients required in a daily diet. The study sheds light on the potential of functional snack bars enriched with FDEBP, offering a delectable way to access essential nutrients and bioactive compounds in a minimally processed form, without the addition of sweeteners or additives, friendly to the gut microbiota.

Perspective: Challenges and Future Directions in Clinical Research with Nuts and Berries

Consumption of nuts and berries are considered part of a healthy eating pattern. Nuts and berries contain a complex nutrient profile consisting of essential vitamins and minerals, fiber, polyunsaturated fatty acids, and phenolics in quantities that improve physiological outcomes. The spectrum of health outcomes that may be impacted by the consumptions of nuts and berries includes cardiovascular, gut microbiome, and cognitive, among others. Recently, new insights regarding the bioactive compounds found in both nuts and berries have reinforced their role for use in precision nutrition efforts. However, challenges exist that can affect the generalizability of outcomes from clinical studies, including inconsistency in study designs, homogeneity of test populations, variability in test products and control foods, and assessing realistic portion sizes. Future research centered on precision nutrition and multi-omics technologies will yield new insights. These and other topics such as funding streams and perceived risk-of-bias were explored at an international nutrition conference focused on the role of nuts and berries in clinical nutrition. Successes, challenges, and future directions with these foods are presented here.

Dietary Recommendations for Ethiopians on the Basis of Priority Diet-Related Diseases and Causes of Death in Ethiopia: An Umbrella Review

Food-based dietary guidelines (FBDG) need to be evidence-based. As part of the development of Ethiopian FBDG, we conducted an umbrella review to develop dietary recommendations. Protein-energy malnutrition (PEM), deficiencies of vitamin A, zinc, calcium, or folate, cardiovascular diseases (CVD), and type 2 diabetes mellitus (T2DM) were selected as a priority. Systematic reviews were eligible if they investigated the impact of foods, food groups, diet, or dietary patterns on priority diseases. After a search, 1513 articles were identified in PubMed, Scopus, and Google Scholar published from January 2014 to December 2021. The results showed that 19 out of 164 systematic reviews reported the impact of diet on PEM or micronutrient deficiencies. Daily 30-90 g whole-grain consumption reduces risk of CVD and T2DM. Pulses improve protein status, and consuming 50-150 g/d is associated with a reduced incidence of CVD and T2DM. Nuts are a good source of minerals, and consuming 15-35 g/d improves antioxidant status and is inversely associated with CVD risk. A daily intake of 200-300 mL of milk and dairy foods is a good source of calcium and contributes to bone mineral density. Limiting processed meat intake to <50 g/d reduces CVD risk. Fruits and vegetables are good sources of vitamins A and C. CVD and T2DM risks are reduced by consuming 200-300 g of vegetables plus fruits daily. Daily sugar consumption should be below 10% of total energy to lower risk of obesity, CVD, and T2DM. Plant-based fat has favorable nutrient profiles and modest saturated fat content. The association of saturated fatty acids with CVD and T2DM is inconclusive, but intake should be limited because of the low-density lipoprotein cholesterol-raising effect. Plant-based diets lower risk of CVD and T2DM but reduce micronutrient bioavailability. The review concludes with 9 key dietary recommendations proposed to be implemented in the Ethiopian FBDG. This review was registered at PROSPERO (CRD42019125490).

Triacylglycerols hydrolysis and hydroxy- and epoxy-fatty acids release during lactic fermentation of plant matrices: An extensive study showing inter- and intra-species capabilities of lactic acid bacteria

This study aims to show that lactic fermentation by selected starters can enrich plant matrices with hydroxy- and oxo-fatty acids. The behavior of 31 lactic acid bacteria strains was investigated during the fermentation of Persian walnut, which was selected as a model growth substrate due to its inherent lipids content. The content of the following free fatty acids increased in the majority of the fermented walnut samples: linoleic, α-linolenic, palmitic, and oleic acids. The increase of diacylglycerols and, especially, monoacylglycerols levels in fermented walnuts confirmed that strain-specific bacterial lipolytic activities hydrolyzed triacylglycerols during walnut fermentation. Twelve hydroxylated or epoxidized derivatives arising from oleic, linoleic, and linolenic fatty acids, in five groups of isomeric compounds, were also identified. In addition to the better-known lactobacilli, certain strains of Weissella cibaria, Leuconostoc mesenteroides, and Enterococcus faecalis emerged for their lipolytic activities and ability to release hydroxy- and epoxy-fatty acids during walnut fermentation.

Metabolomics and Transcriptomics Analyses Reveals the Molecular Regulatory Mechanisms of Walnut (Juglans regia L.) Embryos in Response to Shade Treatment

The walnut is an important nut that has numerous uses worldwide. However, due to dwarf and close plantation methods as well as continuous cloudy or rainy days that occur during periods of walnut oil accumulation, the walnut fruit exhibits varying degrees of stress under low-light conditions. However, the effects of shade on metabolites and genes in walnut embryos remain unclear in the literature. The purpose of this study is to investigate the lipid biosynthesis process that occurs in walnut embryos under shade treatment via the use of metabolomics and transcriptomics analyses. The results indicate that the oil content decreases significantly under shaded conditions, while the protein content increases significantly. The expression levels of fatty acid desaturase 2 (FAD2) and stearoyl-ACP-desaturase (SAD) involved in the lipid biosynthesis mechanism were significantly reduced in the shaded group, which resulted in reductions in oleic (C18:1), linoleic (C18:2), and α-linolenic (C18:3) acids. The reduced oil content was consistent with the downregulation of genes associated with the lipid biosynthesis mechanism. In the amino acid biosynthesis process, the upregulated cysteine synthase (cscK) and anthranilate synthase beta subunit 2 (trpG) genes promoted the accumulation of L-aspartic acid and L-citrulline. The increase in protein content was consistent with the upregulation of genes related to amino acid biosynthesis. Thus, our study provides new insights into the regulatory mechanisms of shade underlying overall walnut fruit quality.

Energy restriction or improvements in diet quality: identifying the best pathway for a longer and healthier life

Obesity is a major risk factor for chronic non-communicable diseases (NCDs) and it has increased to epidemic proportions. Unhealthy diet represents a modifiable risk factor for both obesity and NCDs, however, there is no universal dietary intervention to improve obesity-related NCDs and particularly to reduce the risk for major adverse cardiovascular events. Energy restriction (ER) and diet quality changes, with and without ER, have been widely investigated in preclinical and clinical studies, however, the potential underlying mechanisms driving the benefits of those dietary interventions remain largely unclear. ER affects multiple metabolic, physiological, genetic, and cellular adaptation pathways associated with prolonged lifespan, particularly in preclinical models, while these benefits remain to be established in humans. Moreover, the sustainability of ER and its implementation across the different diseases remains challenging. On the other hand, diet quality with improvements, with or without ER, has been associated with more favorable long-term metabolic and cardiovascular outcomes. This narrative review will describe the role of ER and/or diet quality improvements on the risk for NCDs. It will also discuss the potential mechanisms of action underlying the potential beneficial effects of those dietary approaches.

Nutritional Composition of Plant Protein Beverages on China's Online Market: A Cross-Sectional Analysis

Plant protein beverages are gaining popularity due to various reasons such as lactose intolerance, veganism and health claims. This study aimed to conduct a cross-sectional analysis of plant protein beverages sold online in China, with a focus on assessing their nutritional composition. A total of 251 kinds of plant protein beverages were analyzed, including coconut (n = 58), soy (n = 52), oats (n = 49), walnut (n = 14), almond (n = 11), peanut (n = 5), rice (n = 4), other beans (n = 5), mixed nuts (n = 5) and mixed beverages (n = 48), according to the nutrition label on the commercial package and retailer websites. The results showed that, except for soy beverages, plant protein beverages generally had low protein content, cereal beverages showed relatively high energy and carbohydrate levels, and all plant protein beverages had low sodium content. Additionally, the fortification rate of vitamins and minerals in the analyzed plant protein beverages was found to be extremely low, at only 13.1%. Given the substantial variation in the nutritional composition of plant protein beverages, consumers should pay more attention to the nutrition facts and ingredient information when choosing these beverages.

Nuts and berries from agroforestry systems in temperate regions can form the foundation for a healthier human diet and improved outcomes from diet-related diseases

Agroforestry is a specific type of agroecosystem that includes trees and shrubs with the potential to yield nutrient-rich products that contribute to human health. This paper reviews the literature on the human health benefits of tree nut and berry species commonly associated with agroforestry systems of the United States, considering their potential for preventing certain diet-related diseases. Emphasis is placed on those diseases that are most closely associated with poor outcomes from COVID-19, as they are indicators of confounding health prognoses. Results indicate that tree nuts reduce the risk of coronary heart disease, and walnuts (Juglans species) are particularly effective because of their unique fatty acid profile. Berries that are grown on shrubs have the potential to contribute to mitigation of hypertension, prevention of Type II diabetes, and reduced risk of cardiovascular disease. To optimize human health benefits, plant breeding programs can focus on the traits that enhance the naturally-occurring phytochemicals, through biofortification. Value-added processing techniques should be selected and employed to preserve the phytonutrients, so they are maintained through the point of consumption. Agroforestry systems can offer valuable human health outcomes for common diet-related diseases, in addition to providing many environmental benefits, particularly if they are purposefully designed with that goal in mind. The food system policies in the U.S. might be reoriented to prioritize these food production systems based on the health benefits.

Effect of Walnut Supplementation on Dietary Polyphenol Intake and Urinary Polyphenol Excretion in the Walnuts and Healthy Aging Study

Among all tree nuts, walnuts contain the highest total polyphenols by weight. This secondary data analysis examined the effect of daily walnut supplementation on the total dietary polyphenols and subclasses and the urinary excretion of total polyphenols in a free-living elderly population. In this 2-year prospective, randomized intervention trial (ID NCT01634841), the dietary polyphenol intake of participants who added walnuts daily to their diets at 15% of daily energy were compared to those in the control group that consumed a walnut-free diet. Dietary polyphenols and subclasses were estimated from 24 h dietary recalls. Phenolic estimates were derived from Phenol-Explorer database version 3.6. Participants in the walnut group compared to the control group had a higher intake of total polyphenols, flavonoids, flavanols, and phenolic acids in mg/d (IQR): 2480 (1955, 3145) vs. 1897 (1369, 2496); 56 (42,84) vs. 29 (15, 54); 174 (90, 298) vs. 140 (61, 277); and 368 (246, 569) vs. 242 (89, 398), respectively. There was a significant inverse association between dietary flavonoid intake and urine polyphenol excretion; less urinary excretion may imply that some of the polyphenols were eliminated via the gut. Nuts had a significant contribution to the total polyphenols in the diet, suggesting that a single food like walnuts added to habitual diet can increase the polyphenol intake in a Western population.

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.

Metabolomics and Transcriptomics Provide Insights into Lipid Biosynthesis in the Embryos of Walnut (Juglans regia L.)

Walnut (Juglans regia L.) is an important woody oilseed tree species due to its commercial value. However, the regulation mechanism of walnut oil accumulation is still poorly understood, which restricted the breeding and genetic improvement of high-quality oil-bearing walnuts. In order to explore the metabolic mechanism that regulates the synthesis of walnut oil, we used transcriptome sequencing technology and metabolome technology to comprehensively analyze the key genes and metabolites involved in oil synthesis of the walnut embryo at 60, 90, and 120 days after pollination (DAP). The results showed that the oil and protein contents increased gradually during fruit development, comprising 69.61% and 18.32% of the fruit, respectively, during ripening. Conversely, the contents of soluble sugar and starch decreased gradually during fruit development, comprising 2.14% and 0.84%, respectively, during ripening. Transcriptome sequencing generated 40,631 unigenes across 9 cDNA libraries. We identified 51 and 25 candidate unigenes related to the biosynthesis of fatty acid and the biosynthesis of triacylglycerol (TAG), respectively. The expression levels of the genes encoding Acetyl-CoA carboxylase (ACCase), long-chain acyl-CoA synthetases (LACS), 3-oxoacyl-ACP synthase II (KASII), and glycerol-3-phosphate acyl transfer (GPAT) were upregulated at 60 DAP relative to the levels at 90 and 120 DAP, while the stearoyl-ACP-desaturase (SAD) and fatty acid desaturase 2 (FAD2) genes were highly abundantly expressed during all walnut developmental periods. We found that ABSCISIC ACID INSENSEITIVE3 (ABI3), WRINKLEDl (WRI1), LEAFY COTYLEDON1 (LEC1), and FUSCA3 (FUS3) may be key transcription factors involved in lipid synthesis. Additionally, the metabolomics analysis detected 706 metabolites derived from 18 samples, among which, 4 are implicated in the TAG synthesis, 2 in the glycolysis pathway, and 5 in the tricarboxylic acid cycle (TCA cycle) pathway. The combined analysis of the related genes and metabolites in TAG synthesis showed that phospholipid:diacylglycerol acyltransferase (PDAT) genes were highly abundantly expressed across walnut fruit developmental periods, and their downstream metabolite TAG gradually accumulated with the progression of fruit development. The FAD2 gene showed consistently higher expression during fruit development, and its downstream metabolites 18:2-PC and 18:3-PC gradually accumulated. The ACCase, LACS, SAD, FAD2, and PDAT genes may be crucial genes required for walnut oil synthesis. Our data will enrich public databases and provide new insights into functional genes related to lipid metabolism in walnut.

Effects of Nut Consumption on Blood Lipids and Lipoproteins: A Comprehensive Literature Update

In the present review, we provide a comprehensive narrative overview of the current knowledge on the effects of total and specific types of nut consumption (excluding nut oil) on blood lipids and lipoproteins. We identified a total of 19 systematic reviews and meta-analyses of randomized controlled trials (RCTs) that were available in PubMed from the inception date to November 2022. A consistent beneficial effect of most nuts, namely total nuts and tree nuts, including walnuts, almonds, cashews, peanuts, and pistachios, has been reported across meta-analyses in decreasing total cholesterol (mean difference, MD, -0.09 to -0.28 mmol/L), LDL-cholesterol (MD, -0.09 to -0.26 mmol/L), and triglycerides (MD, -0.05 to -0.17 mmol/L). However, no effects on HDL-cholesterol have been uncovered. Preliminary evidence indicates that adding nuts into the regular diet reduces blood levels of apolipoprotein B and improves HDL function. There is also evidence that nuts dose-dependently improve lipids and lipoproteins. Sex, age, or nut processing are not effect modifiers, while a lower BMI and higher baseline lipid concentrations enhance blood lipid/lipoprotein responses. While research is still emerging, the evidence thus far indicates that nut-enriched diets are associated with a reduced number of total LDL particles and small, dense LDL particles. In conclusion, evidence from clinical trials has shown that the consumption of total and specific nuts improves blood lipid profiles by multiple mechanisms. Future directions in this field should include more lipoprotein particle, apolipoprotein B, and HDL function studies.

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.

Macadamia nut effects on cardiometabolic risk factors: a randomised trial

We sought to examine the effects of daily consumption of macadamia nuts on body weight and composition, plasma lipids and glycaemic parameters in a free-living environment in overweight and obese adults at elevated cardiometabolic risk. Utilising a randomised cross-over design, thirty-five adults with abdominal obesity consumed their usual diet plus macadamia nuts (~15 % of daily calories) for 8 weeks (intervention) and their usual diet without nuts for 8 weeks (control), with a 2-week washout. Body composition was determined by bioelectrical impedance; dietary intake was assessed with 24-h dietary recalls. Consumption of macadamia nuts led to increased total fat and MUFA intake while SFA intake was unaltered. With mixed model regression analysis, no significant changes in mean weight, BMI, waist circumference, percent body fat or glycaemic parameters, and non-significant reductions in plasma total cholesterol of 2⋅1 % (-4⋅3 mg/dl; 95 % CI -14⋅8, 6⋅1) and low-density lipoprotein (LDL-C) of 4 % (-4⋅7 mg/dl; 95 % CI -14⋅3, 4⋅8) were observed. Cholesterol-lowering effects were modified by adiposity: greater lipid lowering occurred in those with overweight v. obesity, and in those with less than the median percent body fat. Daily consumption of macadamia nuts does not lead to gains in weight or body fat under free-living conditions in overweight or obese adults; non-significant cholesterol lowering occurred without altering saturated fat intake of similar magnitude to cholesterol lowering seen with other nuts. Clinical Trial Registry Number and Website: NCT03801837 https://clinicaltrials.gov/ct2/show/NCT03801837?term = macadamia + nut&draw = 2&rank = 1.

Consumption of Nuts and Seeds and Health Outcomes Including Cardiovascular Disease, Diabetes and Metabolic Disease, Cancer, and Mortality: An Umbrella Review

Consumption of nuts and seeds is associated with a range of health outcomes. Summarizing the best evidence on essential health outcomes from the consumption of nuts is essential to provide optimal recommendations. Our objective is to comprehensively assess health outcome associations related to the consumption of nuts and seeds, using a culinary definition including tree nuts and peanuts (registered in PROSPERO: CRD42021258300). Health outcomes of interest include cardiovascular disease, cancer, diabetes, obesity, respiratory disease, mortality, and their disease biomarkers. We present associations for high compared with low consumption, per serving, and dose-response relations. MEDLINE, Embase, Cochrane, and Epistemonikos were searched and screened for systematic reviews and meta-analyses. Evidence was extracted from 89 articles on the consumption of nuts and relevant health outcomes, including 23 articles with meta-analysis on disease and mortality, 66 articles on biomarkers for disease, and 9 articles on allergy/adverse outcomes. Intake of nuts was associated with reduced risk of cardiovascular diseases and related risk factors, with moderate quality of evidence. An intake of 28 g/d nuts compared with not eating nuts was associated with a 21% RR reduction of cardiovascular disease (including coronary heart disease incidence and mortality, atrial fibrillation, and stroke mortality), an 11% risk reduction of cancer deaths, and 22% reduction in all-cause mortality. Nut consumption was also inversely associated with mortality from respiratory diseases, infectious diseases, and diabetes; however, associations between nut consumption and diabetes incidence were mixed. Meta-analyses of trials on biomarkers for disease generally mirrored meta-analyses from observational studies on cardiovascular disease, cancers, and diabetes. Allergy and related adverse reactions to nuts were observed in 1-2% of adult populations, with substantial heterogeneity between studies. Overall, the current evidence supports dietary recommendations to consume a handful of nuts and seeds per day for people without allergies to these foods.

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.

The Effect of Walnut Intake on Lipids: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Cardiovascular diseases (CVD) are the leading causes of death worldwide. Dyslipidemia is a cardiometabolic risk factor of CVD, yet it can be modifiable. Walnuts have been suggested as a dietary intervention to improve the lipid profile. Therefore, we reviewed the literature to assess the evidence linking walnut intake to the improvement of blood lipids, including total cholesterol (TC), low-density lipoprotein (LDL-C) cholesterol, high-density lipoprotein (HDL-C) cholesterol, and triglycerides (TG). PubMed and Embase databases were searched from 2010 up to March 2022. We limited our search to randomized controlled trials conducted on humans and published in English during the specified period. Cochrane's risk of bias tool for interventional studies was used. A random-effects model was used for the meta-analysis, and weighted mean differences were obtained (WMD) Thirteen trials from the U.S., Europe, and Asia were included. Walnut intake was associated with significant reductions in TC (WMD: -8.58 mg/dL), LDL-C (WMD: -5.68 mg/dL), and TG (WMD: -10.94 mg/dL). Walnut consumption was not associated with HDL-C. Subgroup analysis showed that overweight/obese and those with comorbidities had more lipid improvement. A longer trial duration did result in further improvements. However, our results may be prone to bias due to extraneous confounding factors. Additionally, levels of heterogeneity were considerable for some outcomes of interest. Results from this meta-analysis provide evidence for the health benefits of walnuts on blood lipids. Walnuts possibly reduce the risk of CVD; thus, they can be successfully added to a dietary pattern to enhance health benefits.

Impact of α-Linolenic Acid, the Vegetable ω-3 Fatty Acid, on Cardiovascular Disease and Cognition

Given the evidence of the health benefits of plant-based diets and long-chain n-3 (ω-3) fatty acids, there is keen interest in better understanding the role of α-linolenic acid (ALA), a plant-derived n-3 fatty acid, on cardiometabolic diseases and cognition. There is increasing evidence for ALA largely based on its major food sources (i.e., walnuts and flaxseed); however, this lags behind our understanding of long-chain n-3 fatty acids. Meta-analyses of observational studies have shown that increasing dietary ALA is associated with a 10% lower risk of total cardiovascular disease and a 20% reduced risk of fatal coronary heart disease. Three randomized controlled trials (RCTs) [AlphaOmega trial, Prevención con Dieta Mediterránea (PREDIMED) trial, and Lyon Diet Heart Study] all showed benefits of diets high in ALA on cardiovascular-related outcomes, but the AlphaOmega trial, designed to specifically evaluate ALA effects, only showed a trend for benefit. RCTs have shown that dietary ALA reduced total cholesterol, LDL cholesterol, triglycerides, and blood pressure, and epidemiologic studies and some trials also have shown an anti-inflammatory effect of ALA, which collectively account for, in part, the cardiovascular benefits of ALA. A meta-analysis reported a trend toward diabetes risk reduction with both dietary and biomarker ALA. For metabolic syndrome and obesity, the evidence for ALA benefits is inconclusive. The role of ALA in cognition is in the early stages but shows promising evidence of counteracting cognitive impairment. Much has been learned about the health benefits of ALA and with additional research we will be better positioned to make strong evidence-based dietary recommendations for the reduction of many chronic diseases.

Association of nut consumption with CVD risk factors in young to middle-aged adults: The Coronary Artery Risk Development in Young Adults (CARDIA) study

BACKGROUND AND AIMS

Few studies have examined long-term associations of walnut, other nut, and no nut consumption with cardiovascular disease (CVD) risk factors. Results from prospective studies with long-term follow-up can provide further evidence for dietary guideline messaging to consume nuts. Therefore, we examined the associations of walnut, other nut, and no nut consumption with diet quality and CVD risk factors over 30 years of follow-up.

METHODS AND RESULTS

Data were analyzed from 3092 young adults enrolled in the Coronary Artery Risk Development in Young Adults (CARDIA) study. Dietary intake, including walnuts and other nuts, was assessed 3 times over 20 years. CVD risk factors were measured at multiple exams. General linear regression evaluated the associations of walnut, other nut, and no nut consumption with CVD risk factors over 30 years (Y30) of follow-up. The 20-year cumulative mean intake of walnuts (0.74 oz/d), other nuts (1.6 oz/d), or no nut consumption was differentially associated with HEI-2015 and CVD risk factors by Y30. Generally, walnut consumers had significantly higher HEI-2015, lower body mass index, waist circumference, blood pressure, and triglyceride concentration, and gained less weight since baseline than other nut consumers (p ≤ 0.05 for all). Further, walnut consumers had lower fasting blood glucose than no nut consumers (p ≤ 0.05).

CONCLUSION

Study findings that walnut and other nut consumption was associated with better CVD risk factors and diet quality aligns with the 2020-2025 US. Dietary Guidelines for Americans recommendation to consume nuts, such as walnuts, within the context of a healthy diet.

Nut consumption is associated with a shift of the NMR lipoprotein subfraction profile to a less atherogenic pattern among older individuals at high CVD risk

BACKGROUND

Scientific evidence has accumulated on the beneficial effects of nut consumption on cardiovascular risk and cholesterol reduction, but few studies have examined the effects of nuts on advanced measures of lipoprotein atherogenicity determined by nuclear magnetic resonance (NMR) spectroscopy. We analyzed associations between the amount and type of of nuts consumed and advanced measures of lipoprotein atherogenity and insulin resistance in older individuals at high cardiovascular risk.

METHODS

The present observational study was carried out within the framework of the Prevención con Dieta Mediterránea (PREDIMED) trial. Cross-sectional and longitudinal analyses after 1-year of follow-up were conducted in 196 men and women recruited in the PREDIMED-Reus (Spain) center. Dietary intake was assessed using a validated semi-quantitative food questionnaire. Baseline and 1-year fasting plasma lipoprotein and metabolite profiling were performed in plasma using NMR spectra Vantera® Clinical Analyzer. Associations by tertiles of nut consumption between baseline and 1-year changes and advanced measures of lipoprotein atherogenicity, branched chain amminoacids, and measures of insulin resistance were tested by multivariable-adjusted ANCOVA models.

RESULTS

Compared to paticipants in the bottom tertile, those in the top tertile of total nut consumption showed higher levels of large HDL particles and HDL-cholesterol, lower levels of branched-chain amino acids (BCAA) and GlycA, and reduced lipoprotein insulin resistance and diabetes risk index. Participants in the top tertile of walnut consumption disclosed lower levels of very large VLDL, total LDL particles, LDL-cholesterol, and GlycA. Participants in the top tertile of non-walnut nut consumption displayed higher levels of total HDL particles, HDL-cholesterol and apoliporotein A1, lower BCAA and GlycA, and reduced lipoprotein insulin resistance. Participants in the top tertile of 1-year changes in walnut consumption showed increases in medium-sized HDL particles in comparison to the bottom tertile.

CONCLUSIONS

In older individuals at high cardiovascular risk, increasing nut consumption was associated with a shift of the NMR lipoprotein subfraction profile to a less atherogenic pattern, as well as lower circulating concentrations of BCAA and decreased insulin resistance. These results provide novel mechanistic insight into the cardiovascular benefit of nut consumption. Trial registration ISRCTN35739639; registration date: 05/10/2005; recruitment start date 01/10/2003.

Consumption of walnuts suppresses the conversion of palmitic to palmitoleic acid and enhances omega-3 fatty acid metabolism in the heart of fructose-fed rats

Walnut consumption mostly has a positive implication for cardiovascular health. Walnut diet effects on the cardiac fatty acid (FA) metabolism of healthy rats and those with fructose diet-induced metabolic burden were analysed. Both walnuts and fructose increased CD36 transporter level and the nuclear content of some/all of Lipin 1/PPARα/PGC-1 complex partners, as well as cytosolic and nuclear FOXO1. However, fructose, independently of walnuts, increased the content of palmitic (PA), oleic, and vaccenic acid (VA), while in walnut-fed rats failed to increase palmitoleic acid (POA) level and the POA/PA ratio, as well as total MUFA content. In opposite, walnuts reduced the level of PA and VA and increased alpha-linolenic, eicosapentaenoic and docosapentaenoic acid level, regardless of fructose. In conclusion, both fructose and walnuts stimulated the uptake and oxidation of FA in the heart, but the walnuts, opposite to fructose, favourably altered cardiac FA profile in healthy and metabolically compromised rats.

Walnut Intake Interventions Targeting Biomarkers of Metabolic Syndrome and Inflammation in Middle-Aged and Older Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Biomarkers of metabolic syndrome and inflammation are pathophysiological predictors and factors of senescence and age-related diseases. Recent evidence showed that particular diet components, such as walnuts rich in antioxidant bioactive compounds and with a balanced lipid profile, could have positive outcomes on human health. A systematic search in PubMed, EMBASE, Cochrane Library, Scopus, and ClinicalTrials.gov databases was performed to retrieve randomized controlled trials published from the beginning of each database through November 2021, reporting on the outcomes of walnut consumption over 22 metabolic syndrome and inflammatory markers in middle-aged and older adults. The search strategy rendered 17 studies in the final selection, including 11 crossover and 6 parallel trials. The study revealed that walnut-enriched diets had statistically significant decreasing effects for triglyceride, total cholesterol, and LDL cholesterol concentrations on some inflammatory markers and presented no consequences on anthropometric and glycemic parameters. Although further studies and better-designed ones are needed to strengthen these findings, the results emphasize the benefits of including walnuts in the dietary plans of this age group.

The Effect of a Peanut-Enriched Weight Loss Diet Compared to a Low-Fat Weight Loss Diet on Body Weight, Blood Pressure, and Glycemic Control: A Randomized Controlled Trial

The objective of this study was to examine the effect of consuming 35 g of peanuts prior to two main meals per day as part of a weight loss diet, compared to a traditional low-fat weight loss diet, on body weight, markers of glycemic control, and blood pressure in adults at risk of type 2 diabetes over 6 months. A two-arm randomized controlled trial was conducted. Adults (age > 18 years) with a BMI of >26 kg/m2 at risk of type 2 diabetes were randomized to the peanut group or the traditional low-fat-diet group (control). The peanut group was advised to consume 35 g of lightly salted dry-roasted peanuts prior to two main meals per day. Participants in the control group were given education to follow a low-fat diet. Both groups had dietetic counseling to restrict energy intake (women: <5500 kJ/1300 kcal/d; men: <7000 kJ/1700 kcal/d). Outcome assessment occurred at baseline, 3 months, and 6 months. In total, 107 participants were randomized (65% female; mean age 58 ± 14 years, BMI 33 ± 5.4 kg/m2, waist circumference 109 ± 13 cm, AUSDRISK score 15 ± 5 points), and 76 participants completed the study. No between-group difference in body weight (primary outcome) was observed at 6 months (mean difference, −0.12 kg; 95% CI, −2.42, 2.18; p = 0.92). The mean weight loss at 6 months was 6.7 ± 5.1 kg in the cohort (visit p < 0.001). HbA1c, fasting glucose, fasting insulin, 2-h glucose, and HOMA-IR were not different between the groups. Systolic blood pressure was reduced to a greater extent in the peanut group vs. the control group at 6 months (−5.33 mmHg; 95% CI, −9.23, −1.43; p = 0.008). Intake of 35 g of peanuts prior to two main meals per day, in the context of an energy-restricted diet, resulted in weight loss comparable to a traditional low-fat weight loss diet without preloads. Greater systolic blood pressure reductions were observed with peanut intake, which may lower cardiovascular disease risk.

Nuts and Metabolic Syndrome: Reducing the Burden of Metabolic Syndrome in Menopause

Menopause imposes a dramatic fall in estrogens, which is followed by an increase in the proportion of fat. The rising androgen/estrogen ratio along the menopause transition favors the accumulation of central fat, which contributes to insulin resistance and a series of concatenated effects, leading to a higher incidence of metabolic syndrome. The modulatory effect of diet on the metabolic syndrome phenotype has been shown for the Mediterranean diet, and nuts are key determinants of these health benefits. This review of the impact of nuts on the risk factors of the metabolic syndrome cluster examined studies—prioritizing meta-analyses and systemic reviews—to summarize the potential benefits of nut ingestion on the risk of metabolic syndrome associated with menopause. Nuts have a general composition profile that includes macronutrients, with a high proportion of unsaturated fat, bioactive compounds, and fiber. The mechanisms set in motion by nuts have shown different levels of efficacy against the disturbances associated with metabolic syndrome, but a beneficial impact on lipids and carbohydrate metabolism, and a potential, but minimal reduction in blood pressure and fat accumulation have been found.