Effects of walnut oil on lipid profiles in hyperlipidemic type 2 diabetic patients: a randomized, double-blind, placebo-controlled trial

Transcriptome analysis of lipid biosynthesis during kernel development in two walnut (Juglans regia L.) varieties of 'Xilin 3' and 'Xiangling'

BACKGROUND

Walnut is an oilseed tree species and an ecologically important woody tree species that is rich in oil and nutrients. In light of differences in the lipid content, fatty acid composition and key genes expression patterns in different walnut varieties, the key gene regulatory networks for lipid biosynthesis in different varieties of walnuts were intensively investigated.

RESULTS

The kernels of two walnut varieties, 'Xilin 3' (X3) and 'Xiangling' (XL) were sampled at 60, 90, and 120 days post-anthesis (DPA) to construct 18 cDNA libraries, and the candidate genes related to oil synthesis were identified via sequencing and expression analysis. A total of 106 differentially expressed genes associated with fatty acid biosynthesis, fatty acid elongation, unsaturated fatty acid biosynthesis, triglyceride assembly, and oil body storage were selected from the transcriptomes. Weighted gene co-expression network analysis (WGCNA), correlation analysis and quantitative validation confirmed the key role of the FAD3 (109002248) gene in lipid synthesis in different varieties.

CONCLUSIONS

These results provide valuable resources for future investigations and new insights into genes related to oil accumulation and lipid metabolism in walnut seed kernels. The findings will also aid future molecular studies and ongoing efforts to genetically improve walnut.

Chemical Characterization and Beneficial Effects of Walnut Oil on a Drosophila melanogaster Model of Parkinson's Disease

A nutritional approach could be a promising strategy to prevent or decrease the progression of neurodegenerative disorders such as Parkinson's disease (PD). The neuroprotective role of walnut oil (WO) was investigated in Drosophila melanogaster treated with rotenone (Rot), as a PD model, WO, or their combination, and compared to controls. WO reduced mortality and improved locomotor activity impairment after 3 and 7 days, induced by Rot. LC-MS analyses of fatty acid levels in Drosophila heads showed a significant increase in linolenic (ALA) and linoleic acid (LA) both in flies fed with the WO-enriched diet and in those treated with the association of WO with Rot. Flies supplemented with the WO diet showed an increase in brain dopamine (DA) level, while Rot treatment significantly depleted dopamine content; conversely, the association of Rot with WO did not modify DA content compared to controls. The greater intake of ALA and LA in the enriched diet enhanced their levels in Drosophila brain, suggesting a neuroprotective role of polyunsaturated fatty acids against Rot-induced neurotoxicity. The involvement of the dopaminergic system in the improvement of behavioral and biochemical parameters in Drosophila fed with WO is also suggested.

Inhibition of human starch digesting enzymes and intestinal glucose transport by walnut polyphenols

One approach to controlling type 2 diabetes (T2D) is to lower postprandialglucose spikesby slowing down the digestion of carbohydrates and the absorption of glucose in the small intestine. The consumption of walnuts is associated with a reduced risk of chronic diseases such as T2D, suggested to be partly due to the high content of (poly)phenols. This study evaluated, for the first time, the inhibitory effect of a (poly)phenol-rich walnut extract on human carbohydrate digesting enzymes (salivary and pancreatic α-amylases, brush border sucrase-isomaltase) and on glucose transport across fully differentiated human intestinal Caco-2/TC7 monolayers. The walnut extract was rich in multiple (poly)phenols (70 % w/w) as analysed by Folin-Ciocalteau and by LCMS. It exhibited potent inhibition of both human salivary (IC50: 32.2 ± 2.5 µg walnut (poly)phenols (WP)/mL) and pancreatic (IC50: 56.7 ± 1.7 µg WP/mL) α-amylases, with weaker effects on human sucrase (IC50: 990 ± 20 µg WP/mL), maltase (IC50: 1300 ± 80 µg WP/mL), and isomaltase (IC25: 830 ± 60 µg WP/mL) activities. Selected individual walnut (poly)phenols inhibited human salivary α-amylase in the order: 1,3,4,6-tetragalloylglucose > ellagic acid pentoside > 1,2,6-tri-O-galloyl-β-D-glucopyranose, with no inhibition by ellagic acid, gallic acid and 4-O-methylgallic acid. The (poly)phenol-rich walnut extract also attenuated (up to 59 %) the transfer of 2-deoxy-D-glucose across differentiated Caco-2/TC7 cell monolayers. This is the first report on the effect of (poly)phenol-rich extracts from any commonly-consumed nut kernel on any human starch-digesting enzyme, and suggests a mechanism through which walnut consumption may lower postprandial glucose spikes and contribute to their proposed health benefits.

Can daily consumption of enriched fatty acids diet be effective in improving metabolic syndrome? An attractive paradox for walnut kernel

Imagine consuming a daily diet rich in fatty acids to help treat diseases such as hypertension and obesity. This concept presents an attractive paradox. In particular, consuming walnut kernels is beneficial for treating diseases associated with metabolic syndrome (MetS), including type 2 diabetes, cardiovascular disease, dyslipidemia, and obesity. Different parts of the Juglans regia tree (family Juglandaceae), including its leaves, green husks, bark, and septum, have shown promising effects on pathological conditions related to MetS. The therapeutic advantages of consuming walnut kernels for MetS can be attributed to the presence of polyunsaturated fatty acids and polyphenolic compounds such as juglone and ellagic acid. Diets enriched with walnut kernel have a positive impact on MetS complications by reducing diastolic blood pressure, improving blood lipid profiles, lowering fasting blood sugar levels, and increasing insulin sensitivity. The potential cellular mechanisms responsible for these benefits involve activating the cholesterol hemostasis pathway by inhibiting sterol regulatory element-binding proteins (SREBPs), proprotein convertase subtilisin/kexin type 9 (PCSK9), and cholesteryl ester transfer protein (CETP). Furthermore, other by-products of walnuts, such as leaves and green husks, have also demonstrated effectiveness in managing MetS. These findings highlight the potential of incorporating walnut-based products into our diets as a natural approach to combating MetS and its complications.

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.

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.

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.

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.

Effectiveness and Safety of Ayurvedic Medicines in Type 2 Diabetes Mellitus Management: A Systematic Review and Meta-Analysis

Introduction: Many Ayurvedic medicines have the potential for managing type 2 diabetes mellitus (T2DM), with previous systematic reviews demonstrating effectiveness and safety for specific Ayurvedic medicines. However, many of the reviews need updating and none provide a comprehensive summary of all the Ayurvedic medicines evaluated for managing T2DM. Objective: The objective of this systematic review was to evaluate and synthesize evidence on the effectiveness and safety of Ayurvedic medicines for managing T2DM. Inclusion criteria: Published and unpublished RCTs assessing the effectiveness and safety of Ayurvedic medicines for managing T2DM in adults. Methods: The JBI systematic review methodology was followed. A comprehensive search of sources (including 18 electronic databases) from inception to 16 January 2021 was made. No language restrictions were applied. Data synthesis was conducted using narrative synthesis and random effects meta-analyses, where appropriate. Pooled results are reported as mean differences (MD) with 95% confidence intervals (CI). Results: Out of 32,519 records identified from the searches, 219 articles were included in the systematic review representing 199 RCTs (21,191 participants) of 98 Ayurvedic medicines. Overall, in the studies reviewed the methodology was not adequately reported, resulting in poorer methodological quality scoring. Glycated hemoglobin (HbA1c) was reduced using Aegle marmelos (L.) Corrêa (MD -1.6%; 95% CI -3 to -0.3), Boswellia serrata Roxb. (-0.5; -0.7 to -0.4), Gynostemma pentaphyllum (Thunb.) Makino (-1; -1.5 to -0.6), Momordica charantia L. (-0.3; -0.4 to -0.1), Nigella sativa L. (-0.4; -0.6 to -0.1), Plantago ovata Forssk. (-0.9; -1.4 to -0.3), Tinospora cordifolia (Willd.) Hook.f. and Thomson (-0.5; -0.6 to -0.5), Trigonella foenum-graecum L. (-0.6; -0.9 to -0.4), and Urtica dioica L. (-1.3; -2.4 to -0.2) compared to control. Similarly, fasting blood glucose (FBG) was reduced by 4-56 mg/dl for a range of Ayurvedic medicines. Very few studies assessed health-related quality of life (HRQoL). Adverse events were not reported in many studies, and if reported, these were mostly none to mild and predominately related to the gastrointestinal tract. Conclusion: The current evidence suggests the benefit of a range of Ayurvedic medicines in improving glycemic control in T2DM patients. Given the limitations of the available evidence and to strengthen the evidence base, high-quality RCTs should be conducted and reported.

Efficacy of omega-3-rich Camelina sativa on the metabolic and clinical markers in nonalcoholic fatty liver disease: a randomized, controlled trial

OBJECTIVE

Recently, omega-3 fatty acids and antioxidants co-supplementation was considered as alternative treatment in the management of nonalcoholic fatty liver disease (NAFLD). This trial evaluated effects of Camelina sativa oil (CSO) as a rich source of omega-3 fatty acids and antioxidants on anthropometric indices, lipid profile, liver enzymes, and adiponectin in NAFLD patients.

PARTICIPANTS AND METHODS

This triple-blind, placebo-controlled, randomized clinical trial was conducted on 46 NAFLD patients who were randomly assigned to either a CSO supplement or placebo for 12 weeks. Both groups received a loss weight diet. Levels of liver enzymes, adiponectin, lipid profile, atherogenic index, and anthropometric indices were assessed for all patients at baseline and post-intervention.

RESULTS

CSO caused significant differences in weight, BMI, waist circumference, waist-to-hip ratio, triglyceride, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-c), TC/HDL-c, LDL-c/HDL-c, atherogenic index, alanine aminotransferase, and adiponectin concentrations in the CSO group compared with the placebo group (P < 0.046 for all). No significant differences were found in hip circumference, neck circumference, HDL-c, and other liver enzymes in the CSO group compared with the placebo group (P = 0.790, P = 0.091, P = 0.149, P < 0.159 for liver enzymes, respectively).

DISCUSSION AND CONCLUSION

This study showed that CSO supplementation for 12 weeks causes significant changes in all of anthropometric indices (except hip circumference and neck circumference), ALT, lipid profile (except HDL-c), atherogenic index, and adiponectin in NAFLD patients.

The Effect of Dietary Interventions on Hypertriglyceridemia: From Public Health to Molecular Nutrition Evidence

Approximately 25–50% of the population worldwide exhibits serum triglycerides (TG) (≥150 mg/dL) which are associated with an increased level of highly atherogenic remnant-like particles, non-alcoholic fatty liver disease, and pancreatitis risk. High serum TG levels could be related to cardiovascular disease, which is the most prevalent cause of mortality in Western countries. The etiology of hypertriglyceridemia (HTG) is multifactorial and can be classified as primary and secondary causes. Among the primary causes are genetic disorders. On the other hand, secondary causes of HTG comprise lifestyle factors, medical conditions, and drugs. Among lifestyle changes, adequate diets and nutrition are the initial steps to treat and prevent serum lipid alterations. Dietary intervention for HTG is recommended in order to modify the amount of macronutrients. Macronutrient distribution changes such as fat or protein, low-carbohydrate diets, and caloric restriction seem to be effective strategies in reducing TG levels. Particularly, the Mediterranean diet is the dietary pattern with the most consistent evidence for efficacy in HTG while the use of omega-3 supplements consumption is the dietary component with the highest number of randomized clinical trials (RCT) carried out with effective results on reducing TG. The aim of this review was to provide a better comprehension between human nutrition and lipid metabolism.

Effects of nut consumption on blood lipid profile: A meta-analysis of randomized controlled trials

BACKGROUND & AIMS

Several randomized controlled trials (RCTs) have assessed the effects of nut consumption on blood lipid profile. The aim of this study was to conduct a meta-analysis to quantitatively estimate the effects of nut consumption on blood lipid profile.

METHODS AND RESULTS

The PubMed, EMBASE, Cochrane Library, and Google Scholar databases were systematically searched to identify RCTs examining the effects of nut intake on blood total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TGs) from inception until March 2021. A random-effects model was used to pool standardized mean differences (SMDs) and 95% confidence intervals (CIs). Potential publication bias was assessed using Begg's test and Egger's test. Sensitivity analysis was performed to assess the impact of each individual study on the pooled results. The meta-analysis showed that nut consumption had no significant effect on the blood lipid profile. However, there was a significant reduction in TC (SMD: -2.89, 95% CI: -4.80, -0.98, I² = 97.4) for pistachio consumption, and cashew consumption significantly increased HDL-C (SMD: 0.24, 95% CI: 0.04, 0.43, I² = 0.0) compared with that in controls. There was no significant publication bias in the meta-analysis. The sensitivity analysis showed that removing one study at a time did not change the significance of the results.

CONCLUSION

There was no overall effect of nut consumption on lipid profile, and the results may vary depending on nut type. We found that pistachio consumption may reduce TC levels, while cashew consumption increases HDL-C.

REGISTRY NUMBER

PROSPERO CRD42021249147.

Determination of Metals in Walnut Oils by Means of an Optimized and Validated ICP-AES Method in Conventional and Organic Farming Type Samples

Agricultural products are indispensable for equilibrated diets since they discharge minerals and several bioactive constituents. Considering the increasing demand for organic products, research has been conducted over recent years to investigate whether organically grown food products are chemically different compared to those produced with conventional farming. In this work, a novel inductively coupled plasma atomic emission spectrometric method was developed and validated for the determination of nutrient and toxic elements in walnut oils produced with conventional and organic farming. The method presented good linearity (r2 > 0.9990) for each element at the selected emission line. The limits of detection and limits of quantification ranged between 0.09 μg g−1 to 2.43 μg g−1 and 0.28 μg g−1 to 8.1 μg g−1, respectively. Method accuracy and was assessed by analyzing the certified reference materials BCR 278-R and spiked walnut oil samples. The determined metals were quantified, and the results were analyzed by Student’s t-test to investigate the differences in the elemental profile of the walnut oils according to type of farming (conventional or organic).

Screening of Antagonistic Bacteria from Endophytes against Walnut Blight Pathogen Xanthomonas arboricola pv. juglandis

Walnut blight caused by Xanthomonas arboricola pv. juglandis (Xaj) is the most important bacterial disease in walnut production worldwide. To seek biocontrol agents against Xaj, we screened 152 endophytic bacteria isolated from 87 plants. Through dual-culture method screening, we obtained four antagonistic bacteria, ATE17, BME17, CIE17, and OFE17 which were isolated from Amaranthus tricolor, Bambusa multiplex, Canna indica, and Osmanthus fragrans plants respectively. The inhibition ratios of ATE18, BME17, CIE18, and OFE17 against Xaj on plates were 1.5, 1.6, 1.3, and 1.6, respectively. These indicated they have good biocontrol potential for walnut bacterial blight. Subsequently, the four endophytic bacteria were identified by morphology, Gram staining, Microbial Identification System (fatty acid methyl ester analysis), as well as 16S rDNA and gyrB sequencing. It turns out that all four strains were identified as Bacillus sp. Furthermore, the two strains BME17 and OFE17 can suppress multiple plant fungal pathogens and bacterial pathogens on plates.

One-year dietary supplementation with walnuts modifies exosomal miRNA in elderly subjects

PURPOSE

Epidemiological studies and clinical trials support the association of nut consumption with a lower risk of prevalent non-communicable diseases, particularly cardiovascular disease. However, the molecular mechanisms underlying nut benefits remain to be fully described. MicroRNAs (miRNAs) are post-transcriptional regulators of gene expression and play a pivotal role in health and disease. Exosomes are extracellular vesicles released from cells and mediate intercellular communication. Whether nut consumption modulates circulating miRNAs (c-miRNAs) transported in exosomes is poorly described.

METHODS

Cognitively healthy elderly subjects were randomized to either control (n = 110, abstaining from walnuts) or daily supplementation with walnuts (15% of their total energy, ≈30-60 g/day, n = 101) for 1-year. C-miRNAs were screened in exosomes isolated from 10 samples, before and after supplementation, and identified c-miRNA candidates were validated in the whole cohort. In addition, nanoparticle tracking analysis and lipidomics were assessed in pooled exosomes from the whole cohort.

RESULTS

Exosomal hsa-miR-32-5p and hsa-miR-29b-3p were consistently induced by walnut consumption. No major changes in exosomal lipids, nanoparticle concentration or size were found.

CONCLUSION

Our results provide novel evidence that certain c-miRNAs transported in exosomes are modulated by walnut consumption. The extent to which this finding contributes to the benefits of walnuts deserves further research.

Integrated Analysis of Seed microRNA and mRNA Transcriptome Reveals Important Functional Genes and microRNA-Targets in the Process of Walnut (Juglans regia) Seed Oil Accumulation

Walnut (Juglans regia) is known as a promising woody oil crop with abundant polyunsaturated fatty acids in its kernel. However, the regulation mechanism of walnut oil accumulation and fatty acid metabolism is still poorly understood, which restricted the breeding and genetic improvement of high-quality oil-bearing walnuts. To reveal the molecular mechanism of walnut oil accumulation, considering the potential regulation of microRNA (miRNA) in seed development, in this study, the oil content of walnut kernel on the 80th, 100th and 120th day after flowering (DAF) was tested and the corresponding proportions are 11.51%, 40.40% and 53.20%. Between DAF of 80th~120th, the content of stearic acid and oleic acid tended to increase, but the proportion of other fatty acids tended to decrease. Meanwhile, comparative transcriptome and sRNA-seq analysis on three stages (80th, 100th and 120th DAF), found 204 conserved miRNAs and 554 novel miRNAs in walnut kernels, among which 104 key genes related to walnut oil accumulation were screened. The phospholipid:diacylglycerol acyltransferase metabolic pathway may contribute more to oil accumulation in walnut. 16 miRNA-mRNA regulatory modules related to walnut oil accumulation and fatty acid synthesis were constructed. 8 known miRNAs and 9 novel miRNAs regulate 28 genes involved in fatty acid (FA) metabolism and lipid synthesis. Among them, jre-miRn105, jre-miRn434, jre-miR477d and jre-miR156a.2 are key miRNAs that regulate walnut FA synthesis. Jre-miRn411 and jre-miR399a.1 are closely related to oil accumulation. These data provide new insights and lay the foundation for subsequent studies on walnut FA synthesis and oil accumulation.

Characteristics and Antioxidant Potential of Cold-Pressed Oils-Possible Strategies to Improve Oil Stability

The relations of the antiradical capacity to oxidative stability parameters and the contents of fatty acids, sterols, tocopherols, phenols, flavonoids, chlorophyll, Cu, and Fe were assessed in 33 cold-pressed seed oils: Walnut (7 brands of oils), rosehip (3), camelina (6), milk thistle (5), flax (6), and pumpkin (6). The antiradical capacity of oils depended strongly on tocopherol contents with a synergistic effect with polyphenols. The efficacy of tocopherols in cold-pressed oils was accompanied by a negative correlation of their antioxidant capacity with the peroxide value increase after 3 months of shelf life. This study also showed a positive correlation between the content of phytosterols and the antiradical capacity in the lipophilic fraction of cold-pressed oils rich in n-3 polyunsaturated fatty acids (PUFAs). Multiple regression analysis identified groups of antioxidants naturally occurring in cold-pressed oils in relation to their fatty acid composition, which added to the cold-pressed oils could provide possible strategies to improve their stability. Achieving high stability is primarily a result of high phytosterol content exceeding the molar ratio of 1:100 for total phytosterols to α-linolenic acid. However, the molar ratios of tocopherols to linoleic acid below 1:2000 and polyphenols to linoleic acid below 1:3000 does not prevent oxidation in oils with the predominance of linoleic acid.

Beneficial effects of walnut (Juglans regia L.) oil-derived polyunsaturated fatty acid prevents a prooxidant status and hyperlipidemia in pregnant rats with diabetes

BACKGROUND

Gestational diabetes mellitus has a long-term effect on pregnant women. Walnut (Juglans regia L.) oil-derived polyunsaturated fatty acid (PUFA) possesses multifarious pharmacological activities. This study investigated the beneficial effects of walnut oil-derived PUFA on glucose metabolism, pregnancy outcomes, oxidative stress, and lipid metabolism in gestational diabetes mellitus.

METHODS

The GDM rat model was generated by intraperitoneal injection of streptozotocin (40 mg/kg) on gestational day (GD) 6, GD7 and GD8. The differences between groups were estimated using one-way ANOVA followed by the Tukey's multiple comparison test for post-hoc analysis.

RESULTS

The results indicated that PUFA could mitigate GDM in pregnant diabetic rats, as embodied by the decrease of fasting blood glucose and the increase of plasma insulin and hepatic glycogen levels. Also, PUFA could suppress oxidative stress in pregnant diabetic rats, as reflected by the decrease of malondialdehyde content, an increase of superoxide dismutase, catalase and gutathione peroxidase activities. PUFA could also mitigate the abnormal changes of lipid profiles in plasma and hepatic tissue. Moreover, the relative mRNA expression of sterol regulatory element-binding transcription factor-1, stearoyl-CoA desaturase-1, fatty acid synthase, and acetyl-coenzyme A carboxylase, was suppressed by PUFA in pregnant diabetic rats.

CONCLUSIONS

These results suggested that PUFA supplementation during pregnancy is beneficial in preventing diabetic complications in pregnant rats.

Effect of Tree Nuts Consumption on Serum Lipid Profile in Hyperlipidemic Individuals: A Systematic Review

Many epidemiological studies have regularly connected nuts intake with decreased risk for coronary heart disease. The primary mechanism by which nuts protect against cardiovascular disease is through the improvement of lipid and apolipoprotein profile. Therefore, numerous dietary intervention studies investigated the impact of nut consumption on blood lipid levels. Many studies have shown that nut intake can enhance the lipid profile in a dose-response way among individuals with increased serum lipids. This systematic review examines the effectiveness of nuts on the lipid profile among patients with dyslipidemia from different age groups. A total of 29 interventional studies from 5 databases met the inclusion criteria. In all, 20 studies were randomized controlled clinical trials, whereas 9 were crossover-controlled clinical trials. Participants included in the studies were different in terms of age, sex and, serum lipid profile. The studies were inconsistent in the type of tree nuts, duration, dose, and the nut forms. All studies indicated changes in the lipid profile after the intervention particularly on the total cholesterol, high-density lipoprotein, low-density lipoprotein, triglycerides, total cholesterol/high-density lipoprotein. Interventional periods ranged from 3 weeks up to 12 months with doses ranged from 15 to 126 gm. In conclusion, this review provides an evidence of favorable effect of nuts consumption of serum lipid profile.

Effects of walnut oil on metabolic profile and transcription factors in rats fed high-carbohydrate-/-fat diets

The aim of this study was to examine the effects of walnut oil (WO) on metabolic profile and transcription factors in rats fed high carbohydrate (HCD) and high-fat diet (HFD). Forty-two male rats were divided in to six groups: (a) Control, (b) WO (20 mg/kg BW), (c) HCD (20% of sucrose), (d) HCD + WO (e) HFD (42% of calories as fat), and (f) HFD + WO. HFD and HCD intake increased final body weights by 19% and 23% and visceral fat weights by 3- and 5-fold, respectively (p < .05 for all). In addition, serum glucose, total cholesterol, triglyceride, and free fatty acids (FFA) insulin, leptin, and MDA levels increased in rats fed with HFD and HCD. WO supplementation improved these metabolic parameters (p < .05 for all). HFD + WO and HCD + WO treated groups had a significant reduction in serum and liver malondialdehyde (MDA) levels by 12% or 15% (p < .05 for both). In addition, WO supplementation lowered the levels of hepatic nuclear factor kappa B (NF-κB) and NADPH oxidase subunit p22^phox , whereas increased the endothelial-NO synthase (e-NOS), nuclear factor erythroid 2-related factor-2, and sirtuin-1 levels. In conclusion, WO supplementation could alleviate the adverse impacts of both HCD and HFD in the rats. PRACTICAL APPLICATIONS: This study suggests that WO intake can modulate carbohydrate metabolism and increase antioxidant capacity. These properties might be partially mediated through the regulation of the transcription factors and some proteins involved in energy metabolism, as well as a balance of oxidative stress, and insulin sensitivity.

Comparison of the Effects of Brazil Nut Oil and Soybean Oil on the Cardiometabolic Parameters of Patients with Metabolic Syndrome: A Randomized Trial

Recent evidence suggests that replacing saturated fat with unsaturated fat is beneficial for cardiovascular health. This study compared the effects of Brazil nut oil (BNO) and soybean oil (SO) supplementation for 30 days on anthropometric, blood pressure, biochemical, and oxidative parameters in patients with metabolic syndrome (MS). Thirty-one patients with MS were randomly allocated to receive 30 sachets with 10 mL each of either BNO (n = 15) or SO (n = 16) for daily supplementation. Variables were measured at the beginning of the study and after 30 days of intervention. No change in anthropometric and blood pressure variables were observed (p > 0.05). Total (p = 0.0253) and low-density lipoprotein (p = 0.0437) cholesterol increased in the SO group. High-density lipoprotein cholesterol decreased (p = 0.0087) and triglycerides increased (p = 0.0045) in the BNO group. Malondialdehyde levels decreased in the BNO group (p = 0.0296) and total antioxidant capacity improved in the SO group (p = 0.0110). Although the addition of oils without lifestyle interventions did not affect anthropometric findings or blood pressure and promoted undesirable results in the lipid profile in both groups, daily supplementation of BNO for 30 days decreased lipid peroxidation, contributing to oxidative stress reduction.

Global longitudinal strain as an Indicator of cardiac Iron overload in thalassemia patients

Background and objective

Cardiac involvement due to iron overload is the most common cause of morbidity and mortality in patients with thalassemia, and many patients remain asymptomatic until the late stages. Therefore, early detection of heart problems in such patients at subclinical stages can improve the prognosis of these patients. We investigated the role of speckled tracking (SI) and tissue Doppler echocardiography (TDI) in early detection of iron overload in these patients.

Methods

52 thalassemic patients who were receiving regular blood transfusion with normal global LV function were examined by two- and three-dimensional echocardiography. Cardiac MRI was done and T2* images were considered as the non-invasive gold standard for evaluating cardiac iron deposition. Serum ferritin level was assessed and the relationships between serum ferritin levels and echo finding with cardiac MRI T₂^* was investigated.

Results

No significant relationship was seen between serum ferritin levels and cardiac MRI T₂^*. Among the echocardiographic findings, septal systolic myocardial velocity (P = 0.002 and r = 0.43) and global strain (GLS) (P = 0.000 and r = 0.60) were significantly associated with T₂^*. A GLS < 19.5 could predict a T₂^* level below 20 by 82.14% sensitivity and 86.36% specificity (area under the curve = 0.87; p < 0.0001).

Conclusion

While serum ferritin level and ejection fraction are not useful candidates, GLS may be used as a valuable marker to screen thalassemia patients for myocardial iron deposition, using a cut off value below − 19.5. This approach may facilitate the cardiac follow up, reduce the costs, and contribute to preventing deterioration of cardiac function in countries with limited availability of cardiac MRI.

Plant Foods, Antioxidant Biomarkers, and the Risk of Cardiovascular Disease, Cancer, and Mortality: A Review of the Evidence

Although a high intake of plant foods such as fruits, vegetables, whole grains, nuts, and legumes has been recommended for chronic disease prevention, it has been unclear what is the optimal amount of intake of these foods and whether specific subtypes are particularly beneficial. The evidence from several recently published meta-analyses on plant foods and antioxidants and various health outcomes is reviewed as well as more recently published studies. In meta-analyses of prospective studies, inverse associations were observed between intake of fruits, vegetables, whole grains, and nuts and the risk of coronary artery disease, stroke, cardiovascular disease overall, total cancer, and all-cause mortality. The strongest reductions in risk were observed at an intake of 800 g/d for fruits and vegetables, 225 g/d for whole grains, and 15-20 g/d for nuts, respectively. Whole-grain and nut consumption was also inversely associated with mortality from respiratory disease, infections, and diabetes. Stronger and more linear inverse associations were observed between blood concentrations of antioxidants (vitamin C, carotenoids, vitamin E) and cardiovascular disease, cancer, and all-cause mortality than for dietary intake. Most studies that have since been published have been consistent with these results; however, further studies are needed on subtypes of plant foods and less common causes of death. These results strongly support dietary recommendations to increase intake of plant foods, and suggest optimal intakes for chronic disease prevention may be ∼800 g/d for intakes of fruits and vegetables, 225 g/d for whole grains, and 15-20 g/d for nuts. Diets high in plant foods could potentially prevent several million premature deaths each year if adopted globally.

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

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

Potential of Fatty Oils from Traditional Chinese Medicine in Cancer Therapy: A Review for Phytochemical, Pharmacological and Clinical Studies

Cancer management is a worldwide challenge. In addition to effective cancer therapies like chemotherapy, radiotherapy and surgery, treatment based on traditional Chinese medicine (TCM) and combined TCM with western medicine has gradually gained attention in Oriental countries. One potential TCM approach using extracted fatty oils, containing fatty acids which are important active ingredients with a variety of pharmacological activities, makes significant contributions to cancer treatment. The strategies of treating cancer with the fatty oils of TCM were classified into “Fuzheng”, which usually associates with improving immunity, represented by coix seed oil. The other classification is “Quxie”, which relates to inducing apoptosis of cancer cells, and is represented by Brucea javanica oil. Compared with other active substances, the literature about anticancer fatty oils is relatively limited, and most of them focus on the composition and other biological activities without a systematic review. Therefore, based on the theories of “Fuzheng” and “Quxie” in TCM, in this paper, the anticancer effects of fatty oils have been reviewed. The chemical composition, anticancer mechanism, listed drugs, studying dosage form and clinical application of fatty oils have also been discussed. In summary, since there are different types and abundance of fatty oils among botanicals, anticancer effects of fatty oils can be achieved through two TCM theory-based strategies. We hoped that this review paper can reveal the anticancer potential of fatty oils and provide a reference for future related studies.

Walnuts change lipoprotein composition suppressing TNFα-stimulated cytokine production by diabetic adipocyte

Walnut consumption can provide both vascular and metabolic health benefits, and walnut-induced changes in lipoprotein particle chemical payloads may be responsible for these health benefits. To explore this possibility with a focus on metabolic health, this study investigated the impact of walnut consumption on lipoprotein lipid composition and changes in LDL anti-inflammatory properties, as reported by inflamed adipocyte. Hypercholesterolemic, postmenopausal females were treated with 40 g/day (i.e., 1.6 servings/day; n=15) of walnuts for 4 weeks. Fatty acids and their oxygenated metabolites, i.e., oxylipins, were quantified in isolated lipoproteins. Human primary adipocytes were exposed to LDL and TNFα-stimulated adipokine production was measured. Walnut treatment elevated α-linolenic acid and its epoxides in all lipoproteins and depleted mid-chain alcohols in VLDL and LDL, but not HDL. Walnuts also reduced TNFα-induced diabetic adipocyte production of IL-6 (-48%, P=.0006) and IL-8 (-30%, P=.01), changes inversely correlated with levels of α-linolenic acid-derived epoxides but not α-linolenic acid itself. In conclusion, modest walnut consumption can alter lipoprotein lipid profiles and enhance their ability to inhibit TNFα-dependent pro-inflammatory responses in human diabetic primary adipocytes. Moreover, this study suggests the oxylipins, rather than the parent fatty acids, mediate LDL action of adipocytes.

Almond oil for patients with hyperlipidemia: A randomized open-label controlled clinical trial

BACKGROUND

Cardiovascular diseases currently account for nearly half of non-communicable diseases. It was shown that enjoying a handful of nuts every day can significantly reduce the risk of developing heart diseases as they contain a variety of nutrients and other bioactive substances contributing to lowering the risk of heart diseases and controlling the cholesterol. The aim of this study was to determine the effect of almond oil on the lipid profile of patients with hyperlipidemia.

METHODS

Ninety-seven patients were divided into the intervention (n = 49) and control (n = 48) groups. The intervention group received 10 ml of almond oil two times daily for 30 days. There was no intervention for the control group. The serum lipoproteins were measured before and after the study.

RESULTS

The total cholesterol and LDL levels decreased significantly in the intervention group (treatment difference = -16.12 ± 26.16, P = 0.009; treatment difference = -20.88 ± 18.4, p < 0.001 respectively). But regular almond oil consumption did not significantly affect the triglyceride and HDL in this sample of hyperlipidemic patients.

CONCLUSION

Consumption of almond could reduce the total cholesterol and LDL in dyslipidemic patients.

Comparison of the effect of omega-3 supplements and fresh fish on lipid profile: a randomized, open-labeled trial

Background

Dietary fish is a rich source of Omega-3 poly-unsaturated fatty acids (PUFAs). These compounds may have protective effect against cardiovascular events possibly by modifying lipid profiles. Consequently, fish oil supplements are produced commercially to complement low fish intake. It is not clear if both interventions have similar effects. The aim of this trial was to compare the anti-hyperlipidemic effect of omega3 fatty acid supplements with fresh fish.

Method

A total of 106 patients with hyperlipidemia were randomized. One group received 2 g/day of omega-3 capsules for a period of 8 weeks and the other group received a mean of 250 g trout fish twice weekly (for dinner and lunch) for the same time period. The effects of these diets on the lipid profile after the intervention were compared between the two groups.

Results

Data from 48 patients in fish oil group and 47 patients from fish group was used for final analysis. In both groups, total cholesterol, non-HDL cholesterol, triglyceride (TG) levels, and Castelli I index (total cholesterol/HDL ratio) were reduced significantly following the treatment; however, dietary-fish intake had a more pronounced effect (−85.08 ± 74.82 vs. −30.75 ± 89.00, P < 0.001; 75.06 ± 35.43 vs. −16.93 ± 40.21, P < 0.001; −66.55 ± 30.79 vs. −12.7 ± 35.48, P = 0.003; and −0.77 ± 1.39 vs. −3.02 ± 1.85, P < 0.001; respectively). HDL level was increased in both groups with a higher effect in dietary fish group (4.47 ± 7.83 vs. 8.51 ± 8.79, P = 0.022). Atherogenic (Log [TG/HDL ratio]) and Castelli II (LDL/HDL ratio) indices did not change in fish oil group while were reduced significantly by fresh fish consumption (−0.04 ± 0.27 vs. −0.26 ± 0.17, P < 0.001; and 0.15 ± 0.7 vs. -1.32 ± 1.15, P < 0.001, respectively). LDL level was increased in the supplementation group, while it was significantly reduced in the dietary-fish group (+18.7 ± 24.97 vs. −22.75 ± 27.28, P < 0.001).

Conclusion

Consumption of fresh fish seems to be superior in positively modifying the lipid profiles which may have important translations in the occurrence of cardiovascular events.

Metabolic and Blood Pressure Effects of Walnut Supplementation in a Mouse Model of the Metabolic Syndrome

There is extensive evidence that walnut consumption is protective against cardiovascular disease and diabetes in the healthy population, but the beneficial effects of walnut consumption in individuals with the metabolic syndrome (MetS) remain uncertain. We compared a range of cardio-metabolic traits and related tissue gene expression associated with 21 weeks of dietary walnut supplementation in a mouse model of MetS (MetS-Tg) and wild-type (WT) mice (n = 10 per genotype per diet, equal males and females). Compared to standard diet, walnuts did not significantly alter food consumption or body weight trajectory of either MetS-Tg or WT mice. In MetS-Tg mice, walnuts were associated with reductions in oral glucose area under the curve (gAUC, standard diet 1455 ± 54, walnut 1146 ± 91, p = 0.006) and mean arterial blood pressure (MAP, standard diet 100.6 ± 1.9, walnut 73.2 ± 1.8 mmHg, p < 0.001), with neutral effects on gAUC and MAP in WT mice. However, in MetS-Tg mice, walnuts were also associated with trends for higher plasma cholesterol (standard diet 4.73 ± 0.18, walnut 7.03 ± 1.99 mmol/L, p = 0.140) and triglyceride levels (standard diet 2.4 ± 0.5, walnut 5.4 ± 1.6 mmol/L, p = 0.061), despite lowering cholesterol and having no effect on triglycerides in WT mice. Moreover, in both MetS-Tg and WT mice, walnuts were associated with significantly increased liver expression of genes associated with metabolism (Fabp1, Insr), cell stress (Atf6, Ddit3, Eif2ak3), fibrosis (Hgf, Sp1, Timp1) and inflammation (Tnf, Ptpn22, Pparg). In conclusion, dietary walnuts were associated with modest favourable effects in WT mice, but a combination of beneficial and adverse effects in MetS-Tg mice, and up-regulation of hepatic pro-fibrotic and pro-inflammatory genes in both mouse strains.

Effect of Amygdalus scoparia kernel oil consumption on lipid profile of the patients with dyslipidemia: a randomized, open-label controlled clinical trial

Background

Amygdalus scoparia kernel (ASK) oil is traditionally used for Hyperlipidemia. Compared to olive oil, it has higher proportion of unsaturated to saturated fatty acid besides exhibiting higher index of oxidative stability. The lipid-lowering effects of ASK oil however, has not been investigated yet. This study is the first one to evaluate such effects in patients with dyslipidemia.

Results

Serum triglyceride levels significantly decreased in the intervention compared to control group (24.80 ± 51.70 vs 3.13 ± 44.80, p-value = 0.03). Serum total cholesterol, LDL and HDL cholesterol levels did not change significantly (p = 0.28 and p = 0.68 and p = 0.10 respectively).

Materials and Methods

In a double arm, open-label, randomized controlled trial,101 hyperlipidemic patients were recruited. The designation of hyperlipidemia was upon meeting either of the three criteria: having serum low-density lipoprotein (LDL) cholesterol level 130-190 (mg/dl), serum triglyceride level 150-400 (mg/dl), and serum high-density lipoprotein (HDL) cholesterol level less than 50 (mg/dl) for women and 40 (mg/dl) for men. Patients who have ever been prescribed with an antihyperlipidemic medication were excluded. They were randomly assigned to intervention group, receiving the ASK oil, for 60 days and control group. Serum lipid measurements were repeated at the end of the intervention period.

Conclusions

ASK oil supplementation may have a positive effect in reducing serum triglyceride level in patients with dyslipidemia without significant effect on serum cholesterol levels.