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Omega-3 blood biomarkers relate to brain glucose uptake in individuals at risk of Alzheimer’s disease dementia.

Lázaro, I., O. Grau-Rivera, M. Suárez-Calvet, K. Fauria, C. Minguillón, M. Shekari, C. Falcón, M. García-Prat, J. Huguet, J.L. Molinuevo, J.D. Gispert, A. Sala-Vila, 2024. Omega-3 blood biomarkers relate to brain glucose uptake in individuals at risk of Alzheimer’s disease dementia. Alzheimers Dement (Amst). 16(3):e12596. https://doi.org/10.1002/dad2.12596

Introduction: Brain glucose hypometabolism is a preclinical feature of Alzheimer’s disease (AD). Dietary omega-3 fatty acids promote brain glucose metabolism, but clinical research is incipient. Circulating omega-3s objectively reflect their dietary intake. Methods: This was a cross-sectional study in 320 cognitively unimpaired participants at increased risk of AD dementia. Using lipidomics, we determined blood docosahexaenoic (DHA) and alpha-linolenic (ALA) acid levels (omega-3s from marine and plant origin, respectively). We assessed brain glucose metabolism using [18-F]-fluorodeoxyglucose (FDG) positron emission tomography (PET). Results: Blood ALA directly related to FDG uptake in brain areas known to be affected in AD. Stronger associations were observed in apolipoprotein E ε4 carriers and homozygotes. For DHA, significant direct associations were restricted to amyloid beta-positive tau-positive participants. Discussion: Blood omega-3 directly relate to preserved glucose metabolism in AD-vulnerable brain regions in individuals at increased risk of AD dementia. This adds to the benefits of omega-3 supplementation in the preclinical stage of AD dementia. Highlights: Blood omega-3s were related to brain glucose uptake in participants at risk of Alzheimer’s disease (AD) dementia. Complementary associations were observed for omega-3 from marine and plant sources. Foods rich in omega-3 might be useful in early features of AD.

A cross-sectional study on the association of walnut consumption with obesity and relative fat mass among United States adolescents and young adults in NHANES (2003–2020).

Gletsu-Miller, N., Henschel, B., Tekwe, C.D. and Thiagarajah, K., 2024. A cross-sectional study on the association of walnut consumption with obesity and relative fat mass among United States adolescents and young adults in NHANES (2003–2020). Curr Dev in Nutr. 8(8), p.104407. https://doi.org/10.1016/j.cdnut.2024.104407

Background: Walnuts contain nutrients and phytochemicals that can promote metabolic health. However, the high energy content of walnuts along with other nuts raises the concern that consuming nuts promotes obesity. Objectives: We sought to investigate the associations between consumption of walnuts as well as other nuts and measures of obesity in adolescents and young adults. Methods: This study included 8874 adolescents (12–19 y) and 10,323 young adults (20–39 y) from 8 waves of National Health and Nutrition Examination Survey data (2003–2020). The associations of consumption of 1) walnuts only (WO); 2) walnuts with other nuts (WON); 3) other nuts (ON); and 4) no nuts (NN) with obesity status and relative fat mass (RFM) were assessed using logistic and linear regressions stratified by age group and sex. Sample weights were used in all statistical analyses. Results: The mean daily intake of walnuts was not different between the 2 walnut consumption groups within each age group (adolescents: 2.18 [standard error (SE) 0.14] g; P = 0.917; young adults: 4.23 [0.37] g; P = 0.682). The WON group had the lowest prevalence of obesity (adolescents: 8.3%; young adults: 21.1%) while the NN group had the highest prevalence (adolescents: 24.1%; young adults: 35.4%). The models indicated lower odds of obesity in adolescent girls (odds ratio [OR]: 0.27; P < 0.05) and young adult women (OR: 0.58; P < 0.05) who consumed WON than in those who consumed NN. In both young women and girls, RFM was significantly lower in the WON and ON groups than the NN group (P < 0.001). In young men, WON consumption was also associated with a lower RFM (OR: −1.24; 95% confidence interval: −2.21, −0.28) compared with NN consumption. Conclusions: For adolescent girls and young women, dietary intake of walnuts combined with other nuts has the strongest inverse association with measures of obesity.

Original article: adolescent dietary patterns derived using principal component analysis and neuropsychological functions: a cross-sectional analysis of Walnuts Smart Snack cohort.

Ayala-Aldana, N., A. Pinar-Martí, M. Ruiz-Rivera, S. Fernández-Barrés, D. Romaguera, J. Casanova-Mollà, N. Solà-Valls, J. Julvez, 2024. Original article: adolescent dietary patterns derived using principal component analysis and neuropsychological functions: a cross-sectional analysis of Walnuts Smart Snack cohort. Eur Child Adolesc Psychiatry. 2024 Sep 18. https://doi.org/10.1007/s00787-024-02577-6

A balanced diet is relevant for neuropsychological functioning. We aimed to analyze the association between dietary patterns and neuropsychological outcomes in a sample of healthy adolescents of the Walnuts Smart Snack (WSS) cohort from Barcelona city. We performed principal components analysis (PCA) to determine dietary patterns in the adolescent sample using a food frequency questionnaire (60 items). Multiple linear regression models were performed to analyze the association between PCA dietary patterns with neuropsychological outcomes: Strengths and Difficulties (SDQ) externalizing and internalizing scores, Attention Network Test (ANT) Impulsivity Index and Emotional Recognition Task (ERT) scores. We additionally adjusted the models for child sex, age, body mass index (BMI), physical activity and maternal education. Six dietary patterns were identified in PCA analyses. “low consumption of calorie-dense foods” dietary pattern had a negative association (protective) with the both SDQ outcomes (p value < 0.001) and “Nuts” dietary pattern showed a negative (protective) association with impulsivity index (β1= −24.60, 95% CI = −36.80, −12.41, p value < 0.001). Overall, our main results suggest that healthy dietary patterns, including higher intakes of “nuts” and a preference of “low consumption of calorie-dense foods” dietary patterns, could provide a beneficial association with neuropsychological functions during the adolescence period. The associations may include improvements of externalizing and internalizing problem symptoms, and impulsivity.

Identification of new allergens in macadamia nut and cross-reactivity with other tree nuts in a Spanish cohort.

Gutiérrez-Díaz, G., D. Betancor, J. Parrón-Ballesteros, R.G. Gordo, E.S. Castromil-Benito, E. Haroun, M. Vázquez de la Torre, J. Turnay, M. Villalba, J. Cuesta-Herranz, C. Pastor-Vargas, 2024. Identification of new allergens in macadamia nut and cross-reactivity with other tree nuts in a Spanish cohort. Nutrients. 16(7):947. https://doi.org/10.3390/nu16070947

The consumption of macadamia nuts has increased due to their cardioprotective and antioxidant properties. However, this rise is consistent with an increase in the cases of macadamia nut allergy, leading to severe reactions. Although two Macadamia integrifolia allergens (Mac i 1 and Mac i 2) have been identified in Australian and Japanese patients, the allergenic sensitization patterns in Western European populations, particularly in Spain, remain unclear. For this purpose, seven patients with macadamia nut allergy were recruited in Spain. Macadamia nut protein extracts were prepared and, together with hazelnut and walnut extracts, were used in Western blot and inhibition assays. IgE-reactive proteins were identified using MALDI-TOF/TOF mass spectrometry (MS). Immunoblotting assays revealed various IgE-binding proteins in macadamia nut extracts. Mass spectrometry identified three new allergens: an oleosin, a pectin acetylesterase, and an aspartyl protease. Cross-reactivity studies showed that hazelnut extract, but not walnut extract, inhibited macadamia nut oleosin-specific IgE binding. This suggests that oleosin could be used as marker for macadamia-hazelnut cross-reactivity. The results show an allergenic profile in the Spanish cohort different from that previously detected in Australian and Japanese populations. The distinct sensitization profiles observed highlight the potential influence of dietary habits and environmental factors exposure on allergenicity.