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Research Nut: Pine Nuts

Upcycling commercial nut byproducts for food, nutraceutical, and pharmaceutical applications: A comprehensive review.

Alasalvar, C., G. Huang, B.W. Bolling, P.A. Jantip, R.B. Pegg, X.K. Wong, S.K. Chang, E. Pelvan, A.C. de Camargo, G. Mandalari, A. Hossain, F. Shahidi, 2025. Upcycling commercial nut byproducts for food, nutraceutical, and pharmaceutical applications: A comprehensive review. Food Chem. 467:142222. https://doi.org/10.1016/j.foodchem.2024.142222

This article presents a comprehensive overview of upcycling commercial nut byproducts (such as almond, Brazil nut, cashew, hazelnut, macadamia, peanut (also known as a legume), pecan, pine nut, pistachio, and walnut) for food, nutraceutical, and pharmaceutical applications. Upcycling nut byproducts, namely husk/hull, hard shell, brown skin, defatted flour/meal/cake, pine cone, cashew nut shell liquid, cashew apple, walnut septum, and dreg/okara, has great potential, not only to reduce/minimise waste, but also to fit within the circular economy concept. Each byproduct has its own unique functional properties, which can bring significant value. These byproducts can be used as value-added ingredients to promote better health and well-being, due to their rich sources of diverse bioactive components/phytochemicals, polysaccharides, fibre, lignin, prebiotics, oils, proteins, bioactive peptides, minerals, and vitamins, among other components. This comprehensive review provides a basis for future research and development of product applications for nut byproducts. More studies are needed on novel product development to valorise nut byproducts.

Consumption of tree nuts as snacks stimulates changes in plasma fatty acid profiles and adipose tissue gene expression in young adults at risk for metabolic syndrome

Widmer, A., K. Lillegard, K. Wood, M. Robles, R. Fan, F. Ye, J.R. Koethe, H.J. Silver, 2025. Consumption of tree nuts as snacks stimulates changes in plasma fatty acid profiles and adipose tissue gene expression in young adults at risk for metabolic syndrome. Clinical Nutrition. (48)25 – 34. https://doi.org/10.1016/j.clnu.2025.03.002.

Background and aims: The prevalence of metabolic syndrome has been increasing in young adults, concomitant with the occurrence of increased abdominal adiposity. We previously reported that consuming tree nuts, as replacement for typical high-carbohydrate snacks, reduces visceral fat and waist circumference in young adults who have one or more metabolic syndrome risk factors. We aimed to investigate the effects of tree nuts snack consumption on plasma and adipose tissue fatty acid profiles along with changes in the expression of adipose tissue genes involved in thermogenesis, glycemia, adipocyte signaling, lipolysis, and immunity. Methods: A randomized parallel-arm 16-week intervention trial was conducted in 84 adults aged 22-36 years. Participants in both groups were provided with caloric goals for weight maintenance, daily menus, and pre-portioned snacks at every other week visits with study registered dietitians. Changes in dietary fatty acid intakes, plasma and abdominal subcutaneous adipose tissue (SAT) triglycerides fatty acid profiles using gas-liquid chromatography, and the expression of 241 genes in abdominal SAT were evaluated. Results: Consuming tree nuts snacks increased mono- and polyunsaturated fatty acid intakes yielding a 9-fold greater dietary unsaturated to saturated fat ratio. The tree nuts snack group also had significantly greater improvements in plasma 16:1/16:0 ratio; plasma phospholipids oleic and gamma linolenic acid content; plasma diglycerides, triglycerides, and cholesterol esters oleic acid content; and total plasma monounsaturated fatty acids. While abdominal SAT only showed trends for increased oleic acid content and unsaturated to saturated fat ratio, the tree nuts snacks participants had altered expression of 13 genes in abdominal SAT that have roles in nutrient sensing, energy homeostasis, and vulnerability to obesity. Conclusions: Replacing typical high-carbohydrate snacks with tree nuts results in more favorable dietary, plasma, and adipose tissue fatty acid profiles that could aid in preventing the development of excess adiposity and cardiometabolic disease states including metabolic syndrome.

Association of tree nut consumption with cardiovascular disease and cardiometabolic risk factors and health outcomes in US adults: NHANES 2011-2018.

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.

Nuts, Energy Balance and Body Weight.

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.

Circulating linoleic acid at the time of myocardial infarction and risk of primary ventricular fibrillation.

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

Nut consumption in association with overall mortality and recurrence/disease-specific mortality among long-term breast cancer survivors.

Cong, W., K. Gu, F. Wang, H. Cai, W. Zheng, P. Bao, X.-O. Shu, 2022. Nut consumption in association with overall mortality and recurrence/disease-specific mortality among long-term breast cancer survivors. International Journal of Cancer.doi.org/10.1002/ijc.33824.

High nut consumption is associated with reduced total and certain cause-specific mortality in general populations. However, its association with cancer outcomes among long-term breast cancer survivors remains unknown. We examined the associations of nut consumption (including peanuts and tree nuts), assessed at 5-year postdiagnosis, with overall survival (OS) and disease-free survival (DFS) among 3449 long-term breast cancer survivors from the Shanghai Breast Cancer Survival Study, applying Cox regression analysis. During a median follow-up of 8.27 years post dietary assessment, there were 374 deaths, including 252 breast cancer deaths. Among 3274 survivors without previous recurrence at the dietary assessment, 209 developed breast cancer-specific events, that is, recurrence, metastasis or breast cancer mortality. At 5-year post dietary assessment (ie, 10-year postdiagnosis), regular nut consumers had higher OS (93.7% vs 89.0%) and DFS (94.1% vs 86.2%) rates. After multivariable adjustment, nut consumption was positively associated with OS (Ptrend = .022) and DFS (Ptrend = .003) following a dose-response pattern, with hazard ratios (95% confidence interval) of 0.72 (0.52-1.05) for OS and 0.48 (0.31-0.73) for DFS, for participants with greater than median nut intake compared with nonconsumers. The associations did not vary by nut type. Stratified analyses showed that the associations were more evident among participants with a higher total energy intake for OS (Pinteraction = .02) and among participants with early stage (I-II) breast cancers for DFS (Pinteraction = .04). The nut-DFS associations were not modified by estrogen receptor/progesterone receptor status or other known prognostic factors. In conclusion, nut consumption was associated with better survival, particularly DFS, among long-term breast cancer survivors.

The effects of peanuts and tree nuts on lipid profile in type 2 diabetic patients: A systematic review and meta-analysis of randomized, controlled-feeding clinical studies.

Xia, J.Y., J.H. Yu, D.F. Xu, C. Yang, H. Xia, G.J. Sun, 2021. The effects of peanuts and tree nuts on lipid profile in Type 2 diabetic patients: A systematic review and meta-analysis of randomized, controlled-feeding clinical studies. Front. Nutr. https://doi.org/10.3389/fnut.2021.765571

Background: Type 2 diabetes mellitus was found to be associated with metabolic disorders, particularly abnormal glucose and lipid metabolism. Dietary food choices may have profound effects on blood lipids. The primary objective of this study was to examine the effects of peanuts and tree nuts intake on lipid profile in patients with type 2 diabetes. Methods: According to preferred reporting items for systematic reviews and meta-analysis guidelines, we performed a systematic search of randomized controlled clinical trials and systematic reviews published in PubMed, Web of Science, Embase, Scopus, and Cochrane library, from inception through June 2021. Studies in populations with type 2 diabetes, which compare nuts or peanuts to a controlled-diet group were included. We used the mean difference with 95% CIs to present estimates for continuous outcomes from individual studies. In addition, we used the GRADEpro tool to evaluate the overall quality of evidence. Results: Sixteen studies involving 1,041 participants were eligible for this review. The results showed that peanuts and tree nuts supplementation did not induce significant changes in low-density lipoprotein-cholesterol (LDL-C) (mean difference = −0.11; 95%CI: −0.25 – 0.03, p = 0.117) and high-density lipoprotein-cholesterol (HDL-C) (mean difference = 0.01; 95%CI: −0.01 – 0.04, p = 0.400) in patients with type 2 diabetics. In addition, we found that peanuts and tree nuts intake may cause a significantly reduction in total cholesterol (TC) (mean difference = −0.14; 95%CI: −0.26 – −0.02, p = 0.024) and triglyceride (TG) (mean difference = −0.10; 95%CI: −0.17 – −0.02, p = 0.010). In the subgroup analysis, a significantly greater reduction in TC was observed in studies which duration was <12 weeks (mean difference = −0.22; 95%CI: −0.37 – −0.08, p = 0.002). The quality of the body of evidence was “moderate” for TC and TG, the quality of evidence for LDL-C and HDL-C were “low.” Conclusion: Our findings suggest that consuming peanuts and tree nuts might be beneficial to lower TC concentration and TG concentration in type 2 diabetics subjects. Furthermore, peanuts and tree nuts supplementation could be considered as a part of a healthy lifestyle in the management of blood lipids in patients with type 2 diabetes. Given some limits observed in the current studies, more well-designed trials are still needed.

Are fatty nuts a weighty concern? A systematic review and meta-analysis and dose–response meta-regression of prospective cohorts and randomized controlled trials.

Nishi, S.K., E. Viguiliouk, S. Blanco Mejia, C.W.C. Kendall, R.P. Bazinet,  A.J. Hanley, E.M. Comelli, J. Salas Salvado, D.J.A. Jenkins, J.L. Sievenpiper, 2021. Are fatty nuts a weighty concern? A systematic review and meta-analysis and dose–response meta-regression of prospective cohorts and randomized controlled trials. Obes Rev. doi: 10.1111/obr.13330.

Nuts are recommended for cardiovascular health, yet concerns remain that nuts may contribute to weight gain due to their high energy density. A systematic review and meta-analysis of prospective cohorts and randomized controlled trials (RCTs) was conducted to update the evidence, provide a dose-response analysis, and assess differences in nut type, comparator and more in subgroup analyses. MEDLINE, EMBASE, and Cochrane were searched, along with manual searches. Data from eligible studies were pooled using meta-analysis methods. Interstudy heterogeneity was assessed (Cochran Q statistic) and quantified (I2 statistic). Certainty of the evidence was assessed by Grading of Recommendations Assessment, Development, and Evaluation (GRADE). Six prospective cohort studies (7 unique cohorts, n = 569,910) and 86 RCTs (114 comparisons, n = 5873) met eligibility criteria. Nuts were associated with lower incidence of overweight/obesity (RR 0.93 [95% CI 0.88 to 0.98] P < 0.001, “moderate” certainty of evidence) in prospective cohorts. RCTs presented no adverse effect of nuts on body weight (MD 0.09 kg, [95% CI -0.09 to 0.27 kg] P < 0.001, “high” certainty of evidence). Meta-regression showed that higher nut intake was associated with reductions in body weight and body fat. Current evidence demonstrates the concern that nut consumption contributes to increased adiposity appears unwarranted.

The association between left ventricular hypertrophy and consumption of nuts, including peanuts, pine nuts, and almonds.

Park, S.K., C.-M. Oh, J.G. Kang, H.S. Seok, J.Y. Jung, 2021. The association between left ventricular hypertrophy and consumption of nuts, including peanuts, pine nuts, and almonds. Nutr Metab Cardiovasc Dis. 31(1):76-84.

Background and aims: Studies have reported that nut consumption is potentially beneficial in preventing cardiovascular disease. However, data are insufficient regarding the association between nut consumption and left ventricular hypertrophy (LVH). Methods and results: In the Kangbuk Samsung Health Study, the participants were 34,617 men and 12,257 women who completed a food-frequency questionnaire for nut consumption and received echocardiography. Nut consumption was evaluated only for peanuts, pine nuts, and almonds defining 15g as one serving/servings dose. Multivariable adjusted odds ratio (OR) and 95% confidence interval (CI) for LVH were evaluated according to the consumption frequency of one serving dose of nut. The frequency of nut consumption was categorized into five groups (<1/month, 1/month-1/week, 1-2/week, 2-4/week, and ≥4/week). The subgroup analysis was conducted by dividing the participants into the following two groups: the nonhypertensive/nondiabetic group and hypertensive or diabetic group. In women, nut consumption ≥2/week had the lower multivariable adjusted OR and 95% CI for LVH (2-4/week: 0.46 [0.26-0.81] and ≥4/week: 0.48 [0.25-0.92]) when compared with nut consumption <1/month. This association was identically observed in the subgroup analysis for women without hypertension and diabetes mellitus (DM) and women with hypertension or DM. However, men did not show the significant association. Conclusion: In women, nut consumption ≥2/week was associated with the decreased probability of LVH. Further research studies should investigate whether the beneficial effect of nut consumption on LV structure results in better cardiovascular prognosis.

Nut consumption and type 2 diabetes risk: a systematic review and meta-analysis of observational studies.

Becerra-Tomás, N., I. Paz-Graniel, P. Hernández-Alonso, D.J.A. Jenkins, C.W.C. Kendall, J.L. Sievenpiper, J. Salas-Salvadó, 2021. Nut consumption and type 2 diabetes risk: a systematic review and meta-analysis of observational studies. Am J Clin Nutr 00:1–12.

Background: Previous meta-analyses, with some methodological controversies, have assessed the relation between nut consumption and type 2 diabetes (T2D) risk and pointed to contradictory results, making desirable the performance of an updated meta-analysis. Objectives: We aimed to systematically review and meta-analyze all the published studies investigating the relations of total nuts and different types of nuts—i.e., walnuts, peanuts, peanut butter, and total tree nuts—with the prevalence and incidence of T2D. Methods: A systematic search was conducted in the PubMed and Cochrane databases through 12 August, 2020. The inverse variance method with fixed-effect models was used to pool data across studies, expressed as risk ratios (RRs) or ORs and 95% CIs for prospective cohort and cross-sectional studies, respectively. The Cochran Q test and I 2 statistics were used to test and quantify heterogeneity, respectively. Dose-response meta-analysis was also conducted. Results: Eight studies (5 prospective and 3 cross-sectional) were included in the quantitative synthesis. Meta-analyses of crosssectional studies and prospective cohort studies, comparing the highest with the lowest categories, revealed a nonsignificant association between total nut consumption and T2D. Meta-analyses of prospective cohort studies showed an inverse association between peanut butter consumption and T2D incidence (RR: 0.87; 95% CI: 0.77, 0.98; I 2 = 50.6%; Pheterogeneity = 0.16), whereas no association was observed between peanuts or tree nuts and T2D. There was no evidence of a linear dose-response or nonlinear dose-response gradient for total nut and peanut consumption in prospective cohort studies. The certainty of the evidence using NutriGrade was very low for all the exposures. Conclusions: Current results do not demonstrate an association of total nut, peanut, or tree nut consumption with T2D. Peanut butter consumption may be inversely associated with this disease. This review protocol was registered at www.crd.york.ac.uk/prospero/ as CRD42020149756.