Nijssen, K.M., R.P. Mensink, J. Plat, D. Ivanov, H. Preissl, P.J. Joris, 2024. Mixed nut consumption improves brain insulin sensitivity: a randomized, single-blinded, controlled, crossover trial in older adults with overweight or obesity. Am J Clin Nutr. 119(2):314-323. https://doi.org/10.1016/j.ajcnut.2023.12.010
Background: Improving brain insulin sensitivity, which can be assessed by measuring regional cerebral blood flow (CBF) responses to intranasal insulin, may prevent age-related metabolic and cognitive diseases. Objectives: This study aimed to investigate longer-term effects of mixed nuts on brain insulin sensitivity in older individuals with overweight/obesity. Methods: In a randomized, single-blinded, controlled, crossover trial, 28 healthy adults (mean ± standard deviation: 65 ± 3 years; body mass index: 27.9 ± 2.3 kg/m2) received either daily 60-g mixed nuts (15 g of walnuts, pistachio, cashew, and hazelnuts) or no nuts (control) for 16 weeks, separated by an 8-week washout period. Throughout the study, participants were instructed to adhere to the Dutch food-based dietary guidelines. During follow-up, brain insulin action was assessed by quantifying acute effects of intranasal insulin on regional CBF using arterial spin labeling magnetic resonance imaging. Furthermore, effects on peripheral insulin sensitivity (oral glucose tolerance test), intrahepatic lipids, and cardiometabolic risk markers were assessed. Results: Body weight and composition did not change. Compared with control, mixed nut consumption improved regional brain insulin action in 5 clusters located in the left (difference in CBF responses to intranasal insulin: -4.5 ± 4.7 mL/100 g/min; P < 0.001; -4.6 ± 4.8 mL/100 g/min; P < 0.001; and -4.3 ± 3.6 mL/100 g/min; P = 0.007) and right occipital lobes (-4.3 ± 5.6 mL/100 g/min; and -3.9 ± 4.9 mL/100 g/min; P = 0.028). A fifth cluster was part of the left frontal lobe (-5.0 ± 4.6 mL/100 g/min; P < 0.001). Peripheral insulin sensitivity was not affected. Intrahepatic lipid content (-0.7%-point; 95% CI: -1.3%-point to -0.1%-point; P = 0.027), serum low-density lipoprotein cholesterol concentration (-0.24 mmol/L; 95% CI: -0.44 to -0.04 mmol/L; P = 0.019), and systolic blood pressure (-5 mm Hg; 95% CI: -8 to -1 mm Hg; P = 0.006) were lower after the mixed nut intervention. Conclusions: Longer-term mixed nut consumption affected insulin action in brain regions involved in the modulation of metabolic and cognitive processes in older adults with overweight/obesity. Intrahepatic lipid content and different cardiometabolic risk markers also improved, but peripheral insulin sensitivity was not affected.
Nijssen, K.M.R., M.A. Chavez-Alfaro, P.J. Joris, J. Plat, R.P. Mensink, 2024. Effects of longer-term mixed nut consumption on lipoprotein particle concentrations in older adults with overweight or obesity. Nutrients. 17(1):8. https://doi.org/10.3390/nu17010008
Background: Recently, we reported that longer-term mixed nut intake significantly reduced serum total and low-density lipoprotein (LDL)-cholesterol, but these markers may not fully capture lipoprotein-related cardiovascular disease (CVD) risk. Objectives: This randomized, controlled, single-blinded, crossover trial in older adults with overweight or obesity examined the effects of longer-term mixed nut consumption on lipoprotein particle size, number, and lipid distribution. Methods: Twenty-eight participants (aged 65 ±3years; BMI 27.9 ± 2.3 kg/m2) completed two 16-week periods (control [no nuts] vs. mixed nuts (60 g/day: 15g of walnuts, pistachios, cashews, and hazelnuts), separated by an 8-week washout. Plasma lipoprotein particle numbers, sizes, and lipid distributions across subclasses were analyzed using high-throughput nuclear magnetic resonance (NMR) spectroscopy. Results: Mixed nut consumption significantly reduced Apolipoprotein B (ApoB) concentrations (−0.07 g/L; p = 0.009), total cholesterol (−0.27 mmol/L; p = 0.047), non-HDL cholesterol (−0.28 mmol/L; p = 0.022), and total triacylglycerol (TAG) (−0.27 mmol/L; p = 0.008). Total very large-density lipoprotein (VLDL) particle numbers decreased by 24 nmol/L (p < 0.001), with reductions observed across all VLDL subclasses. Total LDL particle numbers (p = 0.044), specifically intermediate-density lipoprotein (IDL) (p = 0.002) and large LDL particles (p = 0.015), were also reduced, while HDL particle numbers and sizes were unaffected. The mixed nut intervention significantly reduced cholesterol concentrations across all VLDL subclasses and IDL (all p < 0.01), with no changes in LDL or HDL subclasses. TAG concentrations showed reductions across all lipoprotein subclasses (all p < 0.05). Conclusions: Longer-term mixed nut consumption may lower CVD risk in older adults and favorable shifts in ApoB-containing lipoprotein subclasses towards a less atherogenic profile.
Sumislawski, K., A. Widmer, R.R. Suro, M.E. Robles, K. Lillegard, D. Olson, J.R. Koethe, H.J. Silver, 2023. Consumption of tree nuts as snacks reduces metabolic syndrome risk in young adults: a randomized trial. Nutrients. 15(24):5051. doi: 10.3390/nu15245051.
Metabolic syndrome (MetSx) and its chronic disease consequences are major public health concerns worldwide. Between-meal snacking may be a modifiable risk factor. We hypothesized that consuming tree nuts as snacks, versus typical carbohydrate snacks, would reduce risk for MetSx in young adults. A prospective, randomized, 16-week parallel-group diet intervention trial was conducted in 84 adults aged 22-36 with BMI 24.5 to 34.9 kg/m2 and ≥1 MetSx clinical risk factor. Tree nuts snacks (TNsnack) were matched to carbohydrate snacks (CHOsnack) for energy (kcal), protein, fiber, and sodium content as part of a 7-day eucaloric menu. Difference in change between groups was tested by analysis of covariance using general linear models. Multivariable linear regression modeling assessed main effects of TNsnack treatment and interactions between TNsnack and sex on MetSx score. Age, BMI, and year of study enrollment were included variables. There was a main effect of TNsnack on reducing waist circumference in females (mean difference: -2.20 ± 0.73 cm, p = 0.004) and a trend toward reduced visceral fat (-5.27 ± 13.05 cm2, p = 0.06). TNsnack decreased blood insulin levels in males (-1.14 ± 1.41 mIU/L, p = 0.05) and multivariable modeling showed a main effect of TNsnack on insulin. Main effects of TNsnack on triglycerides and TG/HDL ratio were observed (p = 0.04 for both) with TG/HDL ratio reduced ~11%. A main effect of TNsnack (p = 0.04) and an interaction effect between TNsnack and sex (p < 0.001) on total MetSx score yielded 67% reduced MetSx score in TNsnack females and 42% reduced MetSx score in TNsnack males. To our knowledge, this is the first randomized parallel-arm study to investigate cardiometabolic responses to TNsnacks versus typical CHOsnacks among young adults at risk of MetSx. Our study suggests daily tree nut consumption reduces MetSx risk by improving waist circumference, lipid biomarkers, and/or insulin sensitivity-without requiring caloric restriction.
Lopez-Neyman, S. M., N. Zohoori, K.S. Broughton, D.C. Miketinas, 2023. Association of tree nut consumption with cardiovascular disease and cardiometabolic risk factors and health outcomes in US adults: NHANES 2011-2018. Curr. Dev. Nutr. 7(10):102007. https://doi.org/10.1016/j.cdnut.2023.102007
Background: Tree nuts are nutrient dense, and their consumption has been associated with improvements in health outcomes. Objective: To estimate the usual tree nut intake and examine the association between tree nut consumption and cardiometabolic (CM) health outcomes in a nationally representative sample of US adults. Methods: Cross-sectional data were analyzed from a sample of 18,150 adults aged ≥ 20y who provided at least one reliable 24-h dietary recall and had complete data for the variables of interest in the NHANES 2011-2018. Tree nut consumers were defined as those consuming ≥ ¼ ounce/d (7.09 g). The National Cancer Institute Method was used to estimate the usual tree nut intake among consumers. Measurement error calibrated regression models were used to assess the association between tree nut consumption and each health outcome of interest. Results: Approximately 8% of all participants (n = 1238) consumed tree nuts and had a mean ± SE usual intake of 39.5 ± 1.8 g/d. Tree nut consumers were less likely to have obesity (31% vs. 40%, P < 0.001) and low high-density lipoprotein cholesterol (22% vs. 30%, P < 0.001) compared with nonconsumers. Moreover, tree nut consumers had a lower mean waist circumference (WC) (97.1 ± 0.7 vs. 100.5 ± 0.3 cm, P < 0.001) and apolipoprotein B (87.5 ± 1.2 vs. 91.8 ± 0.5 mg/dL, P = 0.004) than nonconsumers. After adjusting models for demographics and lifestyle covariates, the difference in WC between average intake (33.7 g/d) and low threshold intake (7.09/g) of tree nuts was -1.42 ± 0.58 cm (P = 0.005). Conclusions: Most US adults do not consume tree nuts, yet modest consumption was associated with decreased prevalence of cardiovascular disease and CM risk factors and improvement for some health outcome measures.
Mandalari, G., T. Gervasi, D.W. Rosenberg, K.G. Lapsley, D.J. Baer, 2023. Effect of nuts on gastrointestinal health. Nutrients. 15(7):1733. https://doi.org/10.3390/nu15071733
Nuts are high nutrient-dense foods containing healthy lipids, dietary fiber, and bioactive phytochemicals, including vitamins and minerals. Although the beneficial effect of nut consumption on different chronic diseases has been well documented, especially in relation to their cardiometabolic benefits, less scientific evidence is available on their possible beneficial effects on gastrointestinal health. In this narrative review, we summarize the most important findings and new research perspectives in relation to the importance of nut consumption on gastrointestinal health. The integrity of the cell wall structure, cell size and particle size after mastication are known to play a crucial role in energy, nutrient and bioactive release from nuts during digestion, therefore affecting bioaccessibility. Other mechanisms, such as cell wall composition, thickness and porosity, as well as stability of the membranes surrounding the oil bodies within the cell, are also important for energy extraction. As the undigested nutrients and phytochemicals are delivered to the colon, effects on gut microbiota composition are predicted. Although the overall effect of nut consumption on microbial alpha- and beta-diversity has been inconsistent, some scientific evidence suggests an increase in fecal butyrate after almond consumption, and a beneficial role of walnuts on the prevention of ulcerative colitis and protection against the development of gastric mucosal lesions.
Nijssen, K.M.R., R.P. Mensink, J. Plat, P.J. Joris, 2023. Longer-term mixed nut consumption improves brain vascular function and memory: A randomized, controlled crossover trial in older adults. Clin Nutr. 42(7):1067-1075. https://doi.org/10.1016/j.clnu.2023.05.025
Background: Nut consumption may reduce age-related cognitive decline, but underlying mechanisms are unclear. Objective: To investigate in older adults longer-term effects of mixed nut consumption on brain vascular function, which may underlie improvements in cognitive performance. Methods: Twenty-eight healthy individuals (age [mean ± SD]: 65 ± 3 years; BMI: 27.9 ± 2.3 kg/m2) were included in a randomized, single-blinded, cross-over trial with a 16-week intervention (60 g/d mixed nuts: walnuts, pistachio, cashew, and hazelnuts) and control period (no nuts), separated by 8 weeks of washout. Participants followed the Dutch food-based dietary guidelines. At the end of each period, cerebral blood flow (CBF), a marker of brain vascular function, was quantified using arterial spin labeling magnetic resonance imaging. Effects on endothelial function, arterial stiffness, and the retinal micro vasculature were also assessed. Cognitive performance was measured using the Cambridge Neuropsychological Test Automated Battery. Results: Body weight remained stable during the study. As compared to the control period, the mixed nut intervention resulted in a higher regional CBF in the right frontal and parietal lobes (treatment effect: 5.0 ± 6.5 mL/100 g/min; P < 0.001), left frontal lobe (5.4 ± 7.1 mL/100 g/min; P < 0.001), and bilateral prefrontal cortex (5.6 ± 6.6 mL/100 g/min; P < 0.001). Carotid artery reactivity (0.7 PP; 95% CI: 0.2 to 1.2; P = 0.007), brachial flow-mediated vasodilation (1.6 PP; 95% CI: 1.0 to 2.2; P < 0.001) and retinal arteriolar calibers were higher (2 µm; 95% CI: 0 to 3; P = 0.037), and carotid-to-femoral pulse wave velocity lower (− 0.6 m/s; 95% CI: −1.1 to −0.1; P = 0.032). Further, visuospatial memory (− 4 errors [16%]; 95%CI: −8 to 0; P = 0.045) and verbal memory (+1 correct [16%]; 0 to 2; P = 0.035) improved, but executive function and psychomotor speed did not change. Conclusions: Longer-term mixed nut consumption as part of a healthy diet beneficially affected brain vascular function, which may relate to the observed beneficial effects on memory in older adults. Moreover, different characteristics of the peripheral vascular tree also improved.
Baer, D.J., M. Dalton, J. Blundell, G. Finlayson, F.B. Hu, 2023. Nuts, Energy Balance and Body Weight. Nutrients. 15(5):1162. doi: 10.3390/nu15051162.
Over several decades, the health benefits of consuming nuts have been investigated, resulting in a large body of evidence that nuts can reduce the risk of chronic diseases. The consumption of nuts, being a higher-fat plant food, is restricted by some in order to minimize weight gain. In this review, we discuss several factors related to energy intake from nuts, including food matrix and its impact on digestibility, and the role of nuts in regulating appetite. We review the data from randomized controlled trials and observational studies conducted to examine the relationship between nut intake and body weight or body mass index. Consistently, the evidence from RCTs and observational cohorts indicates that higher nut consumption does not cause greater weight gain; rather, nuts may be beneficial for weight control and prevention of long-term weight gain. Multiple mechanisms likely contribute to these findings, including aspects of nut composition which affect nutrient and energy availability as well as satiety signaling.
Yang, J., R. Lee, Z. Schulz, A. Hsu, J. Pai, S. Yang, S.M. Henning, J. Huang, J.P. Jacobs, D. Heber, Z. Li., 2023. Mixed nuts as healthy snacks: effect on tryptophan metabolism and cardiovascular risk factors. Nutrients. 15, 569; https://doi.org/10.3390/nu15030569.
We recently demonstrated that the consumption of mixed tree nuts (MTNs) during caloric restriction decreased cardiovascular risk factors and increased satiety. Tryptophan (Trp) metabolism has been indicated as a factor in cardiovascular disease. Here, we investigated the effect of MTNs on Trp metabolism and the link to cardiovascular risk markers. Plasma and stool were collected from 95 overweight individuals who consumed either MTNs (or pretzels) daily as part of a hypocaloric weight loss diet for 12 weeks followed by an isocaloric weight maintenance program for an additional 12 weeks. Plasma and fecal samples were evaluated for Trp metabolites by LC–MS and for gut microbiota by 16S rRNA sequencing. Trp–kynurenine metabolism was reduced only in the MTNs group during weight loss (baseline vs. week 12). Changes in Trp–serotonin (week 24) and Trp–indole (week 12) metabolism from baseline were increased in the MTNs group compared to the pretzel group. Intergroup analysis between MTN and pretzel groups does not identify significant microbial changes as indicated by alpha diversity and beta diversity. Changes in the relative abundance of genus Paludicola during intervention are statistically different between the MTNs and pretzel group with p < 0.001 (q = 0.07). Our findings suggest that consumption of MTNs affects Trp host and microbial metabolism in overweight and obese subjects.
Oliveras, T., I. Lázaro, F. Rueda, G. Cediel, D.L. Bhatt, M. Fitó, F. Madrid-Gambin, O.J. Pozo, W.S. Harris, C. García-García, A. Sala-Vila, A. Bayés-Genís, 2022. Circulating linoleic acid at the time of myocardial infarction and risk of primary ventricular fibrillation. Sci. Rep. 12(1):4377. https://doi.org/10.1038/s41598-022-08453-0
Primary ventricular fibrillation (PVF) is a major driver of cardiac arrest in the acute phase of ST-segment elevation myocardial infarction (STEMI). Enrichment of cardiomyocyte plasma membranes with dietary polyunsaturated fatty acids (PUFA) reduces vulnerability to PVF experimentally, but clinical data are scarce. PUFA status in serum phospholipids is a valid surrogate biomarker of PUFA status in cardiomyocytes within a wide range of dietary PUFA. In this nested case-control study (n = 58 cases of STEMI-driven PVF, n = 116 control non-PVF STEMI patients matched for age, sex, smoking status, dyslipidemia, diabetes mellitus and hypertension) we determined fatty acids in serum phospholipids by gas-chromatography, and assessed differences between cases and controls, applying the Benjamini-Hochberg procedure on nominal P-values to control the false discovery rate (FDR). Significant differences between cases and controls were restricted to linoleic acid (LA), with PVF patients showing a lower level (nominal P = 0.002; FDR-corrected P = 0.027). In a conditional logistic regression model, each one standard deviation increase in the proportion of LA was related to a 42% lower prevalence of PVF (odds ratio = 0.58; 95% confidence interval, 0.37, 0.90; P = 0.02). The association lasted after the inclusion of confounders. Thus, regular consumption of LA-rich foods (nuts, oils from seeds) may protect against ischemia-driven malignant arrhythmias.
Key Area: Heart Health
Mateos, R., M.D. Salvador, G. Fregapane, L. Goya, 2022. Why Should Pistachio Be a Regular Food in Our Diet? Nutrients. 14(15):3207. https://doi.org/10.3390/nu14153207
The pistachio is regarded as a relevant source of biologically active components that, compared to other nuts, possess a healthier nutritional profile with low-fat content composed mainly of monounsaturated fatty acids, a high source of vegetable protein and dietary fibre, remarkable content of minerals, especially potassium, and an excellent source of vitamins, such as vitamins C and E. A rich composition in terms of phytochemicals, such as tocopherols, carotenoids, and, importantly, phenolic compounds, makes pistachio a powerful food to explore its involvement in the prevention of prevalent pathologies. Although pistachio has been less explored than other nuts (walnut, almonds, hazelnut, etc.), many studies provide evidence of its beneficial effects on CVD risk factors beyond the lipid-lowering effect. The present review gathers recent data regarding the most beneficial effects of pistachio on lipid and glucose homeostasis, endothelial function, oxidative stress, and inflammation that essentially convey a protective/preventive effect on the onset of pathological conditions, such as obesity, type 2 diabetes, CVD, and cancer. Likewise, the influence of pistachio consumption on gut microbiota is reviewed with promising results. However, population nut consumption does not meet current intake recommendations due to the extended belief that they are fattening products, their high cost, or teething problems, among the most critical barriers, which would be solved with more research and information.
