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.
Nikodijevic, C.J., Y.C. Probst, S.-Y. Tan, E.P. Neale, 2024. Metabolisable energy from nuts and patterns of nut consumption in the Australian population: a secondary analysis of the 2011–12 National Nutrition and Physical Activity Survey. J Hum Nutr Diet. 37: 538–549. https://doi.org/10.1111/jhn.13278
Background: Nut intake is not associated with increased body weight, which may be explained by their metabolisable energy, among other factors. Therefore, total energy intake may be overestimated among nut consumers. This study aimed to describe the metabolisable energy from nuts and nut consumption patterns in the Australian population. Methods: A nut‐specific database was expanded to include metabolizable energy of nuts (based on nut type and form) and applied to the 2011–12 National Nutrition and Physical Activity Survey (NNPAS). Participants were Australians aged 2 years and older from the 2011–12 NNPAS (n = 12,153, with n = 4,765 nut consumers). Mean metabolisable energy intake was compared with mean energy intake using Atwater factors in nut consumers. Additionally, nut consumption patterns were explored, including the proportion of nuts consumed at meals and snacks. Results: Among nut consumers, mean metabolisable energy from nuts based only on nut type was 241.2 (95% confidence interval [CI]: 232.0, 250.5) kJ/day and mean metabolisable energy considering both nut type and form was 260.7(95% CI: 250.2, 271.2) kJ/day. Energy intake from nuts using Atwater factors was 317.6 (95% CI: 304.8, 330.3) kJ/day. Nuts were more likely to be consumed at snack occasions, with approximately 63% of nut intake occurring as a snack. Conclusion: Application of metabolisable energy to the 2011–12 NNPAS has a significant impact on calculation of energy intake from nuts. Nut consumption patterns identified a majority of nut consumption occurring as snacks. These findings may inform strategies to support nut consumption in Australia.
Goldberg, M.R., M.Y. Appel, K. Tobi, M.B. Levy, N. Epstein-Rigbi, M. Holmqvist, J. Östling, L. Nachshon, J. Lidholm, A. Elizur, 2024. Validation of the NUT CRACKER diagnostic algorithm and prediction for cashew and pistachio co-allergy. J Allergy Clin Immunol Pract. 12(5):1273-1282.
Background: Because of the high cross-sensitization among tree nuts, the NUT CRACKER (Nut Co-reactivity-Acquiring Knowledge for Elimination Recommendations) study proposed a diagnostic algorithm to minimize the number of required oral food challenges (OFCs). Objective: To validate the algorithm for cashew and pistachio allergy and determine markers for allergic severity. Methods: Patients (n = 125) with a median age of 7.8 (interquartile range, 5.9-11.2) years with suspected tree nut allergy were evaluated prospectively with decision tree points on the basis of skin prick test (SPT), basophil activation test (BAT), and knowledge of the coincidence of allergies. Validation of allergic status was determined by OFC. Markers of clinical severity were evaluated using the combined original and prospective cohort (n = 187) in relationship to SPT, BAT, and Ana o 3-sIgE. Results: Reactivity to cashew in SPT, BAT, and Ana o 3-sIgE and the incidence of abdominal pain on challenge were significantly higher in dual-allergic cashew/pistachio patients (n = 82) versus single cashew allergic patients (n = 18) (P = .001). All 3 diagnostic tests showed significant inverse correlation with log10 reaction doses for positive cashew OFC. The algorithm reduced overall the total number of OFCs by 72.0%, with a positive predictive value and negative predictive value of 93.0% and 99.0%, respectively. Cashew false-positives were observed primarily in hazelnut-allergic patients (P = .026). In this population, Ana o 3-specific IgE could diagnose cashew allergy with a sensitivity of more than 90% and a specificity of more than 95%. Conclusions: The NUT CRACKER diagnostic algorithm was validated and reduced the number of diagnostic OFCs required. Markers for severity phenotypes may guide oral immunotherapy protocols, improving the risk/benefit ratio for patients.
Cuadrado, C., C. Arribas, A. Sanchiz, M.M. Pedrosa, P. Gamboa, D. Betancor, C. Blanco, B. Cabanillas, R. Linacero, 2024. Effects of enzymatic hydrolysis combined with pressured heating on tree nut allergenicity. Food Chem. 451:139433. https://doi.org/10.1016/j.foodchem.2024.139433
Hazelnut, pistachio and cashew are tree nuts with health benefits but also with allergenic properties being prevalent food allergens in Europe. The allergic characteristics of these tree nuts after processing combining heat, pressure and enzymatic digestion were analyzed through in vitro (Western blot and ELISA) and in vivo test (Prick-Prick). In the analyzed population, the patients sensitized to Cor a 8 (nsLTP) were predominant over those sensitized against hazelnut seed storage proteins (Sprot, Cor a 9 and 14), which displayed higher IgE reactivity. The protease E5 effectively hydrolyzed proteins from hazelnut and pistachio, while E7 was efficient for cashew protein hydrolysis. When combined with pressured heating (autoclave and Controlled Instantaneous Depressurization (DIC)), these proteases notably reduced the allergenic reactivity. The combination of DIC treatment before enzymatic digestion resulted in the most effective methodology to drastically reduce or indeed eliminate the allergenic capacity of tree nuts.
