Umbrella Review of Systematic Reviews and Meta-Analyses on the Consumption of Different Food Groups and the Risk of Overweight and Obesity
Background/objectives: Dietary choices play an essential role in energy balance and weight gain. This systematic umbrella review investigates the association between the intake of various food groups (whole grains, refined grains, fruits, vegetables, nuts, legumes, fish, eggs, total dairy, red meat, white meat, processed meat, added sugar, and sugar-sweetened beverages) and their associations to the risk of obesity and being overweight. Methods: We systematically searched Medline, Embase, Web of Science, and Epistemonikos for systematic reviews and meta-analyses. A total of 2925 articles were screened, and 13 articles were included in our analysis. Results: For each food group, data included a mean of 166,100 participants and 36,760 cases, ranging from 19,885 participants and 7183 cases for red meat to 520,331 participants and 91,256 cases for nuts. Heterogeneity was high for most of the food groups except for whole grains and sugar-sweetened beverages. The quality of the most comprehensive meta-analyses was high for all food groups, except for processed meats, which was of low quality. High intakes of whole grains, legumes, nuts, and fruits are associated with a reduced risk of overweight and obesity. In contrast, high intakes of red meat and sugar-sweetened beverages are associated with increased risk of overweight and obesity. No significant results were found for the remaining food groups, and no meta-analysis was found for fish, eggs, white meat, and added sugars. Conclusions: Diets rich in whole grains, legumes, nuts, and fruits are associated with a lower risk of developing obesity and being overweight. In contrast, diets high in red meat and sugar-sweetened beverages are associated with an increased risk of overweight and obesity.
https://doi.org/10.3390/nu17040662
Nut Consumption Is Associated with Cognitive Status in Southern Italian Adults
Background: Nut consumption has been considered a potential protective factor against cognitive decline. The aim of this study was to test whether higher total and specific nut intake was associated with better cognitive status in a sample of older Italian adults. Methods: A cross-sectional analysis on 883 older adults (>50 y) was conducted. A 110-item food frequency questionnaire was used to collect information on the consumption of various types of nuts. The Short Portable Mental Status Questionnaire was used to assess cognitive status. Multivariate logistic regression analyses were performed to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for the association between nut intake and cognitive status after adjusting for potential confounding factors. Results: The median intake of total nuts was 11.7 g/day and served as a cut-off to categorize low and high consumers (mean intake 4.3 g/day vs. 39.7 g/day, respectively). Higher total nut intake was significantly associated with a lower prevalence of impaired cognitive status among older individuals (OR = 0.35, CI 95%: 0.15, 0.84) after adjusting for potential confounding factors. Notably, this association remained significant after additional adjustment for adherence to the Mediterranean dietary pattern as an indicator of diet quality, (OR = 0.32, CI 95%: 0.13, 0.77). No significant associations were found between cognitive status and specific types of nuts.
https://doi.org/10.3390/nu17030521
Effect of Cashew Nut Consumption on Biomarkers of Copper and Zinc Status in Adolescents with Obesity: A Randomized Controlled Trial
Background: Children and adolescents with obesity have altered serum copper (Cu) and zinc (Zn) levels, which are associated with oxidative stress, inflammation, and health outcomes. The inclusion of cashew nuts in an adequate diet may provide health benefits and help improve the mineral status of individuals with obesity. Objective: To evaluate the effects of cashew nut consumption on biomarkers of Cu and Zn status in adolescents with obesity. Methods: This was a randomized controlled trial conducted in adolescents. The participants were divided into a control group (CON) and a cashew nut group (CASN). The CASN group received 30 g/day of roasted cashew nuts for 12 weeks, and both groups received nutritional counseling during the study. Anthropometric, dietary, and biochemical parameters (Zn, Cu, and superoxide dismutase (SOD)) were assessed at the baseline and at the end of the study. Association tests, within-group and between-group mean comparisons, and analyses of variation between study periods (Δ T12-T0) were performed. Results: The sample consisted of 81 adolescents who completed the intervention period, resulting in 54 in the CASN group and 27 in the CON group. After the intervention, the CASN group presented a decrease in plasma Cu (p = 0.004) and an increase in SOD (p = 0.030). Both groups showed an increase in plasma Zn (p < 0.050) and a decrease in the Cu/Zn ratio (p < 0.001). CASN had a negative effect on the Cu concentration, which was significantly different from that of CON (p = 0.004). Conclusions: The consumption of cashew nuts for 12 weeks reduced plasma Cu levels in adolescents with obesity. Nutritional counseling may have contributed to the increase in plasma Zn levels in all the study participants.
https://doi.org/10.3390/nu17010163
Effects of Longer-Term Mixed Nut Consumption on Lipoprotein Particle Concentrations in Older Adults with Overweight or Obesity
Background: Recently, we reported that longer-term mixed nut intake significantly reduced serum total and low-density lipoprotein (LDL)-cholesterol, but these markers may not fully capture lipoprotein-related cardiovascular disease (CVD) risk. Objectives: This randomized, controlled, single-blinded, crossover trial in older adults with overweight or obesity examined the effects of longer-term mixed nut consumption on lipoprotein particle size, number, and lipid distribution. Methods: Twenty-eight participants (aged 65 ± 3 years; BMI 27.9 ± 2.3 kg/m2) completed two 16-week periods (control [no nuts] vs. mixed nuts (60 g/day: 15 g of walnuts, pistachios, cashews, and hazelnuts), separated by an 8-week washout. Plasma lipoprotein particle numbers, sizes, and lipid distributions across subclasses were analyzed using high-throughput nuclear magnetic resonance (NMR) spectroscopy. Results: Mixed nut consumption significantly reduced Apolipoprotein B (ApoB) concentrations (−0.07 g/L; p = 0.009), total cholesterol (−0.27 mmol/L; p = 0.047), non-HDL cholesterol (−0.28 mmol/L; p = 0.022), and total triacylglycerol (TAG) (−0.27 mmol/L; p = 0.008). Total very large-density lipoprotein (VLDL) particle numbers decreased by 24 nmol/L (p < 0.001), with reductions observed across all VLDL subclasses. Total LDL particle numbers (p = 0.044), specifically intermediate-density lipoprotein (IDL) (p = 0.002) and large LDL particles (p = 0.015), were also reduced, while HDL particle numbers and sizes were unaffected. The mixed nut intervention significantly reduced cholesterol concentrations across all VLDL subclasses and IDL (all p < 0.01), with no changes in LDL or HDL subclasses. TAG concentrations showed reductions across all lipoprotein subclasses (all p < 0.05). Conclusions: Longer-term mixed nut consumption may lower CVD risk in older adults and favorable shifts in apoB-containing lipoprotein subclasses towards a less atherogenic profile.
https://doi.org/10.3390/nu17010008
Tree Nut Allergy in Children—What Do We Know? —A Review
Food allergy represents a significant public health concern, with its prevalence increasing in recent decades. Tree nuts are among major allergenic foods, and allergies to them are frequently linked to severe and potentially life-threatening reactions. Data on the prevalence and natural history of tree nut allergy are limited. Primary nut allergy typically presents with rapid-onset IgE-mediated symptoms. Diagnosis can be confirmed by demonstrating a positive skin prick test (SPT), specific IgE (sIgE), or through an oral food challenge. Component-resolved diagnostics (CRD) can identify those with a high risk of anaphylaxis. The main management strategy involves avoiding the culprit allergen and treating symptoms after accidental exposure. New therapeutic options, such as sublingual immunotherapy, oral food immunotherapy, with or without omalizumab, and other monoclonal antibodies, are being investigated to modify tree nut allergy. Tree nut allergy is a lifelong disease with a low likelihood of resolution. The aim of this paper is to present the current data on the prevalence, diagnosis, natural history, and management options for tree nut allergy.
https://doi.org/10.3390/nu16233978
Regulation of Intestinal Inflammation by Walnut-Derived Bioactive Compounds
Walnuts (Juglans regia L.) have shown promising effects in terms of ameliorating inflammatory bowel disease (IBD), attributed to their abundant bioactive compounds. This review comprehensively illustrates the key mechanisms underlying the therapeutic potential of walnuts in IBD management, including the modulation of intestinal mucosa permeability, the regulation of inflammatory pathways (such as NF-kB, COX/COX2, MAPCK/MAPK, and iNOS/NOS), relieving oxidative stress, and the modulation of gut microbiota. Furthermore, we highlight walnut-derived anti-inflammatory compounds, such as polyunsaturated fatty acids (PUFA; e.g., ω-3 PUFA), tocopherols, phytosterols, sphingolipids, phospholipids, phenolic compounds, flavonoids, and tannins. We also discuss unique anti-inflammatory compounds such as peptides and polysaccharides, including their extraction and preparation methods. Our review provides a theoretical foundation for dietary walnut supplementation in IBD management and provides guidance for academia and industry. In future, research should focus on the targeted isolation and purification of walnut-derived anti-inflammatory compounds or optimizing extraction methods to enhance their yields, thereby helping the food industry to develop dietary supplements or walnut-derived functional foods tailored for IBD patients. https://doi.org/10.3390/nu16162643
The Effects of Almond Consumption on Cardiovascular Health and Gut Microbiome: A Comprehensive Review
The consumption of almonds has been associated with several health benefits, particularly concerning cardiovascular and intestinal health. In this comprehensive review, we compile and deliberate studies investigating the effects of almond consumption on cardiovascular disease (CVD) risk factors and gut health. Almonds are rich in monounsaturated fats, fiber, vitamins, minerals, and polyphenols, which contribute to their health-promoting properties. Regular intake of almonds has been shown to improve lipid profiles by reducing LDL cholesterol and enhancing HDL functionality. Additionally, almonds aid in glycemic control, blood pressure reduction, and chronic inflammation amelioration, which are critical for cardiovascular health. The antioxidant properties of almonds, primarily due to their high vitamin E content, help in reducing oxidative stress markers. Furthermore, almonds positively influence body composition by reducing body fat percentage and central adiposity and enhancing satiety, thus aiding in weight management. Herein, we also contemplate the emerging concept of the gut–heart axis, where almond consumption appears to modulate the gut microbiome, promoting the growth of beneficial bacteria and increasing short-chain fatty acid production, particularly butyrate. These effects collectively contribute to the anti-inflammatory and cardioprotective benefits of almonds. By encompassing these diverse aspects, we eventually provide a systematic and updated perspective on the multifaceted benefits of almond consumption for cardiovascular health and gut microbiome, corroborating their broader consideration in dietary guidelines and public health recommendations for CVD risk reduction. https://doi.org/10.3390/nu16121964
Identification of New Allergens in Macadamia Nut and Cross-Reactivity with Other Tree Nuts in a Spanish Cohort
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.
https://doi.org/10.3390/nu16070947
Bean and Nut Intake Were Protective Factors for Comorbid Hypertension and Hyperuricemia in Chinese Adults: Results from China Nutrition and Health Surveillance (2015-2017)
This study aimed to describe the prevalence of comorbid hypertension and hyperuricemia (HH) and detected the dietary factors for HH in Chinese adults aged 18 to 64 years. All of the data were collected from the China Nutrition and Health Surveillance 2015–2017, with a stratified, multistage, random sampling method on a national scale. A total of 52,627 adult participants aged 18~64 years from the CNHS 2015–2017 were included in this study. HH was identified as SUA level cut-offs for males and females of 420 μmol/L and 360 μmol/L, respectively, with mean systolic blood pressure ≥140 mmHg and/or mean diastolic blood pressure ≥ 90 mmHg and/or received antihypertensive treatment within two weeks. The differences in HH prevalence between or among the subgroups were compared by the Rao–Scott chi-square test. The correlations between HH and covariates or metabolic factors were detected by a weighted two-level multivariate survey logistic regression. The total weighted sufficient intake ratios of beans and nuts, vegetables, and red meat were 59.1%, 46.6%, and 64.8%, respectively. The weighted prevalence of HH in the total participants was 4.7% (95% CI: 4.3–5.0%). The positive effects of bean and nut on HH were observed. The participants who had sufficient bean and nut intake showed lower risk for HH (for the total participants: OR = 0.734, 95% CI = 0.611–0.881). The prevalence of HH might have been a public health problem, and bean and nut intake might be a protective factor for HH in the Chinese population. https://doi.org/10.3390/nu16020192
A Dietary Model of Partial Meat Replacement with Walnuts Demonstrates Changes in the Nutrient Profile and Quality of the United States Population's Diet
The purpose of the study is to assess the impact of partial meat replacement with walnuts using a dose-escalation approach on nutrient intake and diet quality in the usual US diet. Food modeling was implemented using the nationally representative 2015-2018 National Health and Examination Survey (NHANES), with a focus on non-nut consumers, which included 2707 children and adolescents and 5190 adults. Walnuts replaced meat in a dose-escalating manner (0.5, 1, 1.5, and 2 oz walnuts per day replaced 1, 2, 3, and 4 oz meat, respectively). Diet quality was estimated using the population ratio method of the 2015 Healthy Eating Index. The usual intake of nutrients was estimated using the National Cancer Institute method. Significant differences were determined using non-overlapping 95% confidence intervals. The partial replacement of meat with walnuts demonstrated significant increases in the mean intake of fiber, magnesium, and omega-3 fatty acids and significant decreases in cholesterol and vitamin B12 in the modeled diets for children, adolescents, and adults. Additionally, the partial replacement of meat with walnuts improved overall diet quality. Walnut consumption at 1-2 oz as a replacement for some meat may improve nutrient intake and diet quality across age groups. https://doi.org/10.3390/nu15214518