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Research Nut: Pine Nuts

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

Liu, K., S. Hui, B. Wang, K. Kaliannan, X. Guo, L. Liang, 2020. Comparative effects of different types of tree nut consumption on blood lipids: a network meta-analysis of clinical trials. Am J Clin Nutr. 111(1):219-227.

Background: Recent evidence has confirmed that nuts are one of the best food groups at reducing LDL cholesterol and total cholesterol (TC). However, the comparative effects of different types of nuts on blood lipids are unclear. Objectives: This network meta-analysis of randomized clinical trials aimed to assess the comparative effects of walnuts, pistachios, hazelnuts, cashews, and almonds on typical lipid profiles. Methods: We conducted literature searches to identify studies comparing ≥2 of the following diets-walnut-enriched, pistachio-enriched, hazelnut-enriched, cashew-enriched, almond-enriched, and control diets-for the management of triglycerides (TGs), LDL cholesterol, TC, and HDL cholesterol. Random-effects network meta-analyses, ranking analyses based on the surface under the cumulative ranking (SUCRA) curves, and sensitivity analyses according to the potential sources of heterogeneity across the included studies were performed for each outcome. Results: Thirty-four trials enrolling 1677 participants were included in this study. The pistachio-enriched diet was ranked best for TG (SUCRA: 85%), LDL cholesterol (SUCRA: 87%), and TC (SUCRA: 96%) reductions. For TG and TC reductions, the walnut-enriched diet was ranked as the second-best diet. Regarding LDL cholesterol reduction, the almond-enriched diet was ranked second best. The pistachio-enriched and walnut-enriched diets were more effective at lowering TG, LDL cholesterol, and TC compared with the control diet. Regarding TG and TC reductions, the pistachio-enriched diet was also more effective than the hazelnut-enriched diet. For TG reduction, the walnut-enriched diet was better than the hazelnut-enriched diet. However, these findings are limited by the low quality of evidence ratings. In addition, the quality of this network meta-analysis was limited by the small number and generally poor reporting of available studies. Conclusions: The pistachio-enriched and walnut-enriched diet could be better alternatives for lowering TGs, LDL cholesterol, and TC compared with other nut-enriched diets included in this study. The findings warrant further evaluation by more high-quality studies. This network meta-analysis was registered at www.crd.york.ac.uk/PROSPERO as CRD42019131128.

Tree nut snack consumption is associated with better diet quality and CVD risk in the UK adult population: National Diet and Nutrition Survey (NDNS) 2008–2014.

Dikariyanto, V., S.E. Berry, G.K. Pot, L. Francis, L. Smith, W.L. Hall, 2020. Tree nut snack consumption is associated with better diet quality and CVD risk in the UK adult population: National Diet and Nutrition Survey (NDNS) 2008–2014. Public Health Nutrition. 23(17), 3160–3169.

Objectives: To examine associations of tree nut snack (TNS) consumption with diet quality and cardiovascular disease (CVD) risk in UK adults from National Diet and Nutrition Survey (NDNS) 2008–2014. Design: Cross-sectional analysis using data from 4-d food diaries, blood samples and physical measurements for CVD risk markers. To estimate diet quality, modified Mediterranean Diet Score (MDS) and modified Healthy Diet Score (HDS) were applied. Associations of TNS consumption with diet quality and markers of CVD risk were investigated using survey-adjusted multivariable linear regression adjusted for sex, age, ethnicity, socio-economic and smoking status, region of residency and total energy and alcohol intake. Setting: UK free-living population. Subjects: 4738 adults (≥19 years). Results: TNS consumers had higher modified MDS and HDS relative to non-consumers. TNS consumers also had lower BMI, WC, SBP and DBP and higher HDL compared to non-consumers, although a dose-related fully adjusted significant association between increasing nut intake (g per 4184 kJ/1000 kcal energy intake) and lower marker of CVD risk was only observed for SBP. TNS consumption was also associated with higher intake of total fat, mono-, n-3 and n-6 polyunsaturated fatty acids, fibre, vitamin A, thiamin, folate, vitamin C, vitamin E, potassium, magnesium, phosphorus, selenium and iron; and lower intake of saturated fatty acids, trans fatty acids, total carbohydrate, starch, free sugar, sodium and chloride. Conclusions: TNS consumers report better dietary quality and consumption was associated with lower CVD risk factors. Encouraging replacement of less healthy snacks with TNS should be encouraged as part of general dietary guidelines.

Nut consumption and risk of cancer: A meta-analysis of prospective studies.

Long, J., Z. Ji, P. Yuan, T. Long, K. Liu, J. Li, L. Cheng, 2020. Nut consumption and risk of cancer: A meta-analysis of prospective studies. Cancer Epidemiol Biomarkers Prev. doi: 10.1158/1055-9965.EPI-19-1167.

Background: Epidemiologic studies have investigated the association between nut intake and risk for multiple cancers. However, current findings are inconsistent and no definite conclusion has been drawn from prospective studies. We therefore conducted this meta-analysis to evaluate the relationship between nut consumption and risk of cancer. Methods: Prospective studies reporting associations between nut intake and risk for all types of cancer were identified by searching Web of Science and PubMed databases up to June 2019. Risk ratios (RR) and 95% confidence intervals (CI) were extracted and then pooled across the studies using a random-effect model. A dose–response analysis was modeled by performing restricted cubic splines when data were available. Results: Thirty-three studies that included more than 50,000 cancer cases were eligible for the analysis. When comparing the highest with the lowest category of nut intake, high consumption of nuts was significantly associated with decreased risk of overall cancer (RR= 0.90; 95% CI, 0.85–0.95). The protective effect of nut consumption was especially apparent against cancers from the digestive system (RR=0.83; 95% CI, 0.77–0.89). Among different nut classes, significant association was only obtained for intake of tree nuts. We also observed a linear dose–response relationship between nut consumption and cancer: Per 20 g/day increase in nut consumption was related to a 10% (RR=0.90; 95% CI, 0.82–0.99) decrease in cancer risk. Conclusions: Our analysis demonstrated an inverse association of dietary nut consumption with cancer risk, especially for cancers from the digestive system. Impact: This study highlights the protective effect of nuts against cancer.

Metabolic syndrome features and excess weight were inversely associated with nut consumption after 1-year follow-up in the PREDIMED-Plus study.

Julibert, A., M. del Mar Bibiloni, L. Gallardo-Alfaro, M. Abbate, M.Á. Martínez-González, J. Salas-Salvadó, D. Corella, M. Fitó, J.A. Martínez, Á.M. Alonso-Gómez, J. Wärnberg, J. Vioque, D. Romaguera, J. Lopez-Miranda, R. Estruch, F.J. Tinahones, J. Lapetra, L. Serra-Majem, N. Cano-Ibañez, V. Martín-Sánchez, X. Pintó, J.J. Gaforio, P. Matía-Martín, J. Vidal, C. Vázquez, L. Daimiel, E. Ros, C. Sayon-Orea, N. Becerra-Tomás, I.M. Gimenez-Alba, O. Castañer, I. Abete, L. Tojal-Sierra, J. Pérez-López, L. Notario-Barandiaran, A. Colom, A. Garcia-Rios, S. Castro-Barquero, R. Bernal, J.M. Santos-Lozano, C.I. Fernández-Lázaro, P. Hernández-Alonso, C. Saiz, M.D. Zomeño, M.A. Zulet, M.C. Belló-Mora, J. Basterra-Gortari, S. Canudas, A. Goday, J.A. Tur, PREDIMED-PLUS investigators, 2020. Metabolic syndrome features and excess weight were inversely associated with nut consumption after 1-year follow-up in the PREDIMED-Plus study. J Nutr. 00:1–10.

Background: High nut consumption has been previously associated with decreased prevalence of metabolic syndrome (MetS) regardless of race and dietary patterns. Objectives: The aim of this study was to assess whether changes in nut consumption over a 1-y follow-up are associated with changes in features of MetS in a middle-aged and older Spanish population at high cardiovascular disease risk. Methods: This prospective 1-y follow-up cohort study, conducted in the framework of the PREvención con DIeta MEDiterránea (PREDIMED)-Plus randomized trial, included 5800 men and women (55-75 y old) with overweight/obesity [BMI (in kg/m2) ≥27 and <40] and MetS. Nut consumption (almonds, pistachios, walnuts, and other nuts) was assessed using data from a validated FFQ. The primary outcome was the change from baseline to 1 y in features of MetS [waist circumference (WC), glycemia, HDL cholesterol, triglyceride (TG), and systolic and diastolic blood pressure] and excess weight (body weight and BMI) according to tertiles of change in nut consumption. Secondary outcomes included changes in dietary and lifestyle characteristics. A generalized linear model was used to compare 1-y changes in features of MetS, weight, dietary intakes, and lifestyle characteristics across tertiles of change in nut consumption. Results: As nut consumption increased, between each tertile there was a significant decrease in WC, TG, systolic blood pressure, weight, and BMI (P < 0.05), and a significant increase in HDL cholesterol (only in women, P = 0.044). The interaction effect between time and group was significant for total energy intake (P < 0.001), adherence to the Mediterranean diet (MedDiet) (P < 0.001), and nut consumption (P < 0.001). Across tertiles of increasing nut consumption there was a significant increase in extra virgin olive oil intake and adherence to the MedDiet; change in energy intake, on the other hand, was inversely related to consumption of nuts. Conclusions: Features of MetS and excess weight were inversely associated with nut consumption after a 1-y follow-up in the PREDIMED-Plus study cohort. This trial was registered at isrctn.com as ISRCTN89898870.