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
