Nut consumption and body weight

Genetic engineering and genome editing technologies as catalyst for Africa's food security: the case of plant biotechnology in Nigeria

Many African countries are unable to meet the food demands of their growing population and the situation is worsened by climate change and disease outbreaks. This issue of food insecurity may lead to a crisis of epic proportion if effective measures are not in place to make more food available. Thus, deploying biotechnology towards the improvement of existing crop varieties for tolerance or resistance to both biotic and abiotic stresses is crucial to increasing crop production. In order to optimize crop production, several African countries have implemented strategies to make the most of this innovative technology. For example, Nigerian government has implemented the National Biotechnology Policy to facilitate capacity building, research, bioresource development and commercialization of biotechnology products for over two decades. Several government ministries, research centers, universities, and agencies have worked together to implement the policy, resulting in the release of some genetically modified crops to farmers for cultivation and Commercialization, which is a significant accomplishment. However, the transgenic crops were only brought to Nigeria for confined field trials; the manufacturing of the transgenic crops took place outside the country. This may have contributed to the suspicion of pressure groups and embolden proponents of biotechnology as an alien technology. Likewise, this may also be the underlying issue preventing the adoption of biotechnology products in other African countries. It is therefore necessary that African universities develop capacity in various aspects of biotechnology, to continuously train indigenous scientists who can generate innovative ideas tailored towards solving problems that are peculiar to respective country. Therefore, this study intends to establish the role of genetic engineering and genome editing towards the achievement of food security in Africa while using Nigeria as a case study. In our opinion, biotechnology approaches will not only complement conventional breeding methods in the pursuit of crop improvements, but it remains a viable and sustainable means of tackling specific issues hindering optimal crop production. Furthermore, we suggest that financial institutions should offer low-interest loans to new businesses. In order to promote the growth of biotechnology products, especially through the creation of jobs and revenues through molecular farming.

A Randomized, Crossover Trial Assessing Appetite, Energy Metabolism, Blood Biomarkers, and Ad Libitum Food Intake Responses to a Mid-Morning Pecan Snack vs. an Equicaloric High-Carbohydrate Snack in Healthy Volunteers with Overweight/Obesity

BACKGROUND

The differential effects of pecans versus other popular snack foods on appetite and blood markers of metabolism and satiety have not been well studied. This study investigated the effects of a single mid-morning snack of pecans or tortilla chips on subjective appetite, food intake, blood measures of hormones and metabolites, and resting energy expenditure.

METHODS

Twenty participants with overweight and obesity were enrolled in a within-participants, randomized crossover trial. Participants had indwelling catheters placed for blood sampling and were fed a standardized breakfast, followed two hours later by a 250 kcal snack of either pecans or tortilla chips, and then by a self-selected lunch. Visual analog scale (VAS) appetite measures, blood markers, and energy expenditure were taken at intervals after food consumption.

RESULTS

VAS ratings, energy, food intake and macronutrient composition did not differ between treatment conditions, but glucose and insulin were significantly more elevated after tortilla chips. Free fatty acids (FFA), triglycerides (TG), peptide YY (PYY), and glucagon-like peptide-1 (GLP-1) were higher after consuming pecans compared to tortilla chips.

CONCLUSIONS

Pecan consumption improves postprandial glucose and insulin profiles which would be beneficial to individuals at risk of developing type 2 diabetes. Further studies are needed to investigate whether increased relative secretion of PYY and GLP-1 after eating pecans versus tortilla chips may affect subjective appetite and energy intake if consumed chronically.

Almond supplementation on appetite measures, body weight, and body composition in adults: A systematic review and dose-response meta-analysis of 37 randomized controlled trials

BACKGROUND AND OBJECTIVE

Almond consumption has an inverse relationship with obesity and factors related to metabolic syndrome. However, the results of available clinical trials are inconsistent. Therefore, we analyzed the results of 37 randomized controlled trials (RCTs) and evaluated the association of almond consumption with subjective appetite scores and body compositions.

METHODS

Net changes in bodyweight, body mass index (BMI), waist circumference (WC), fat mass (FM), body fat percent, fat-free mass (FFM), waist-to-hip ratio (WHR), visceral adipose tissue (VAT), and subjective appetite scores were used to calculate the effect size, which was reported as a weighted mean differences (WMD) and 95% confidence interval (CI).

RESULTS

This meta-analysis was performed on 37 RCTs with 43 treatment arms. The certainty in the evidence was very low for appetite indices, body fat percent, FFM, VAT, and WHR, and moderate for other parameters as assessed by the GRADE evidence profiles. Pooled effect sizes indicated a significant reducing effect of almond consumption on body weight (WMD: -0.45 kg, 95% CI: -0.85, -0.05, p = 0.026), WC (WMD: -0.66 cm, 95% CI: -1.27, -0.04, p = 0.037), FM (WMD: -0.66 kg, 95% CI: -1.16, -0.17, p = 0.009), and hunger score (WMD: -1.15 mm, 95% CI: -1.98, -0.32, p = 0.006) compared with the control group. However, almond did not have a significant effect on BMI (WMD: -0.20 kg m-2, 95% CI: -0.46, 0.05, p = 0.122), body fat percent (WMD: -0.39%, 95% CI: -0.93, 0.14, p = 0.154), FFM (WMD: -0.06, 95% CI: -0.47, 0.34, p = 0.748), WHR (WMD: -0.04, 95% CI: -0.12, 0.02, p = 0.203), VAT (WMD: -0.33 cm, 95% CI: -0.99, 0.32), fullness (WMD: 0.46 mm, 95% CI: -0.95, 1.88), desire to eat (WMD: 0.98 mm, 95% CI: -4.13, 2.23), and prospective food consumption (WMD: 1.08 mm, 95% CI: -2.11, 4.28). Subgroup analyses indicated that consumption of ≥50 g almonds per day resulted in a significant and more favorable improvement in bodyweight, WC, FM, and hunger score. Body weight, WC, FM, body fat percent, and hunger scores were decreased significantly in the trials that lasted for ≥12 weeks and in the subjects with a BMI < 30 kg/m2. Furthermore, a significant reduction in body weight and WC was observed in those trials that used a nut-free diet as a control group, but not in those using snacks and other nuts. The results of our analysis suggest that almond consumption may significantly improve body composition indices and hunger scores when consumed at a dose of ≥50 g/day for ≥12 weeks by individuals with a BMI < 30 kg/m2.

CONCLUSION

However, further well-constructed randomized clinical trials are needed in order ascertain the outcome of our analysis.

Daily Cashew and Brazil Nut Consumption Modifies Intestinal Health in Overweight Women on Energy-Restricted Intervention: A Randomized Controlled Trial (Brazilian Nuts Study)

BACKGROUND

Increased intestinal permeability and dysbiosis are related to obesity. Nuts can provide nutrients and bioactive compounds that modulate gut microbiota and inflammation, enhancing the beneficial effects of weight loss.

OBJECTIVES

To evaluate the effect of consuming cashew nuts (Anacardium occidentale L.) and Brazil nuts (Bertholletia excelsa H.B.K) on intestinal permeability and microbiota, fecal SCFAs and pH, inflammation, and weight loss in energy restriction condition.

METHODS

In this 8-week randomized controlled trial, 40 women with overweight or obesity were assigned to energy-restricted groups (-500 kcal/d): control group (free of nuts) or Brazilian nuts group (BN: 30 g of cashew nuts and 15 g of Brazil nuts per day). Permeability was analyzed by the lactulose/mannitol test and the microbiota by sequencing the 16S gene in the V3-V4 regions. Plasma concentrations of inflammatory cytokines (TNF, IL-6, IL-10, IL-8, IL-17A) and C-reactive protein were analyzed.

RESULTS

In total, 25 women completed the intervention. Both groups lost weight without statistical differences. Lactulose excretion increased only in the control group (P < 0.05). The BN consumption increased fecal propionic acid and potentially beneficial bacteria, such as Ruminococcus, Roseburia, strains NK4A214 and UCG-002 from the Ruminococcaceae family, but also Lachnospiraceae family, Bacteroides, and Lachnoclostridium, when compared to the control group. Changes in intestinal permeability were correlated to a greater reduction in body fat (kg), and IL-8, and increases in Ruminococcus abundance.

CONCLUSION

Our findings demonstrate a positive impact of BN consumption within an energy-restricted context, linked to the augmentation of potentially beneficial bacteria and pathways associated with body fat reduction. Besides, BN consumption mitigated increased intestinal permeability, although its capacity to diminish permeability or enhance weight loss proved limited. This trial was registered at the Brazilian Registry of Clinical Trials as ReBEC (ID: RBR-3ntxrm).

Effects of energy-restricted diets with or without nuts on weight, body composition and glycaemic control in adults: a scoping review

Energy-restricted (ER) diets promote weight loss and improve body composition and glycaemic control. Nut consumption also improves these parameters. However, less is known about the combined benefit of these two strategies. This scoping review implemented a systematic search of Medline, Embase and Scopus to identify randomised controlled trials evaluating the effect of ER diets with or without nuts on body mass, body composition and glycaemic control in adults. After reviewing titles and abstracts, twenty-nine full-text articles were screened, resulting in seven studies reported in eight papers that met the inclusion criteria. Energy restriction was achieved by prescribing a set energy target or reducing intake by 1000-4200 kJ from daily energy requirements. Interventions ranged from 4 to 52 weeks in duration and contained 42-84 g/d of almonds, peanuts, pistachios or walnuts. While all studies reported that energy restriction resulted in significant weight loss, the addition of nuts to ER diets demonstrated significantly greater weight loss in only approximately half of the included studies (4/7 studies). There was limited evidence to support additional benefits from nuts for body composition measures or glycaemic control. Although improvements in weight loss and glycaemia were not consistent when nuts were included in ER diets, no study revealed an adverse effect of nut consumption on health outcomes. Future studies could explore the effect of consuming different types and amounts of nuts, combined with various levels of energy restriction on weight, body composition and glycaemic control.

Role of diet and exercise in aging, Alzheimer's disease, and other chronic diseases

Alzheimer's disease (AD) is a progressive neurodegenerative disease, characterized by memory loss and multiple cognitive impairments. Genetic mutations cause a small proportion (1-2%) of early-onset AD, with mutations in amyloid precursor protein (APP), presenilin 1 (PS1) and presenilin 2 (PS2). Major contributing factors of late-onset AD are ApoE4 genotype, traumatic brain injury, diabetes, obesity, hypertension, cardiovascular conditions, in addition to lifestyle factors, such as unhealthy diet and lack of physical exercise. Disease progression can be delayed and/or prevented to a greater extent by adopting healthy lifestyle with balanced and antioxidant enriched diet and daily exercise. The interaction and interplay of diet, exercise, age, and pharmacological interventions holds a crucial role in the progression, pathogenesis and management of AD and its comorbidities, including diabetes, obesity, hypertension and cardiovascular conditions. Antioxidant enriched diet contributes to brain health, glucose control, weight management, and cardiovascular well-being. Regular exercise removes toxins including free radicals and enhances insulin sensitivity, and supports cardiovascular function. In the current article, we discussed, the role of diet, and exercise in aging, AD and other conditions including diabetes, obesity, hypertension, cardiovascular conditions. This article also highlights the impact of medication, socioeconomic and lifestyle factors, and pharmacological interventions. These aspects were discussed in different races and ethnic groups in Texas, and the US.

Nuts, Energy Balance and Body Weight

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.

Lifestyle Risk Factors for Overweight/Obesity in Spanish Children

Childhood obesity is one of the main public health concerns in Europe. The aim was to identify possible risk factors associated with overweight/obesity in Spanish preschool and school-age children. The sample (1075 (50.7% girls) children aged 3 to 12) is part of the project 'Alimentando el Cambio' whose objective is to promote healthy lifestyles in schools. Child height and weight were measured, and parents filled out questionnaires related to the children's lifestyle. There was a positive and significant association between sweetened beverage consumption and body mass index (BMI) z-score in both sexes and age groups. There was a negative and significant association between BMI z-score and dairy products in girls of both age groups. There was also a protective effect of regular nut consumption on overweight/obesity in girls 6-12 y. Night-time sleep during weekdays showed a negative association with BMI z-score for older boys and girls. A positive and significant association was found between total screen time and BMI z-score during weekdays. Regarding emotional well-being and self-esteem, having girls 6-12 y laughing and feeling happy and good about themselves in the last week was a protective factor against overweight/obesity. Childhood obesity prevention efforts may benefit from targeting these key risk factors.

Antifungal Activity of Bacillus velezensis CE 100 against Anthracnose Disease (Colletotrichum gloeosporioides) and Growth Promotion of Walnut (Juglans regia L.) Trees

Walnut anthracnose caused by Colletotrichum gloeosporioides is a deleterious disease that severely affects the production of walnut (Juglans regia L.). The aim of this study was to assess the antifungal and growth promotion activities of Bacillus velezensis CE 100 as an alternative to chemical use in walnut production. The crude enzyme from B. velezensis CE 100 exhibited chitinase, protease, and β-l,3-glucanase activity and degraded the cell wall of C. gloeosporioides, causing the inhibition of spore germination and mycelial growth by 99.3% and 33.6% at 100 µL/mL, respectively. The field application of B. velezensis CE 100 culture broth resulted in a 1.3-fold and 6.9-fold decrease in anthracnose disease severity compared to the conventional and control groups, respectively. Moreover, B. velezensis CE 100 produced indole-3-acetic acid (up to 1.4 µg/mL) and exhibited the potential for ammonium production and phosphate solubilization to enhance the availability of essential nutrients. Thus, field inoculation of B. velezensis CE 100 improved walnut root development, increased nutrient uptake, enhanced chlorophyll content, and consequently improved total biomass by 1.5-fold and 2.0-fold compared to the conventional and control groups, respectively. These results demonstrate that B. velezensis CE 100 is an effective biocontrol agent against anthracnose disease and a potential plant growth-promoting bacteria in walnut tree production.

The effect of almond intake on lipid profile: a systematic review and meta-analysis of randomized controlled trials

A number of clinical trials have examined the effect of almond intake on lipid profile in recent years; however, the results remain equivocal. Therefore, the present study aims to summarize and quantitatively examine the available evidence on the effectiveness of almond intake on lipid parameters by employing a systematic review and meta-analytic approach. Online databases including PubMed, Scopus, Embase, and Cochrane Library were searched up to September 2020 for randomized controlled trials that examined the effect of almond intake on lipid profile in adults. Treatment effects were expressed as weighted mean difference (WMD) and the corresponding standard error (SE) in the concentrations of serum lipids. To estimate the overall effect of almond intake, we employed the random-effect model. In total, 27 studies with 36 effect sizes were included in our analysis (1154 cases and 904 control subjects). The meta-analysis revealed that almond intake significantly changed the concentrations of triglycerides (WMD = -6.68 mg dL-1; 95% CI: -11.62, -1.75, p = 0.008), total cholesterol (WMD = -4.92 mg dL-1; 95% CI: -7.81, -2.03, p = 0.001), and low-density lipoproteins (WMD = -5.65 mg dL-1; 95% CI: -8.75, -2.55, p < 0.001); however it did not have a significant effect on high-density lipoprotein (WMD = -0.21 mg dL-1; 95% CI: -1.26, 0.84, p = 0.697) levels. Meta-regression analysis indicated a linear relationship between the dose of almond and change in TG (P = 0.021). This meta-analysis concludes that almond intake can significantly reduce lipid parameters. To draw straightforward conclusions regarding generalized recommendations for almond intake for improving lipid profile, there is a need for more well-controlled trials exclusively targeting patients with dyslipidaemia.

Effects of cashew nut consumption on body composition and glycemic indices: A meta-analysis and systematic review of randomized controlled trials

BACKGROUND AND AIMS

Present meta-analysis and systematic review was conducted to synthesis a definitive conclusion from previous randomized controlled clinical trials (RCTs).

METHODS

A comprehensive search was done up to July 2020, in order to extract RCTs which investigated the effect of cashew nut on weight, body mass index (BMI), waist circumference (WC), fasting blood sugar (FBS), insulin, and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR). Weighted mean difference (WMD) and 95% confidence interval (CI) were used to estimate effect size. Meta regression analysis was done to identify probable sources of heterogeneity.

RESULTS

Six clinical trials with 521 participants were included. Combined effect sizes demonstrated no effect of cashew consumption on weight (WMD): 0.02, 95% CI: -1.04, 1.09, P > 0.05), BMI (WMD: 0.1, 95% CI: -0.72, 0.74, P > 0.05), and WC (WMD: -0.13, 95% CI: -1.97, 1.70, P > 0.05). Results were also not significant for FBS (WMD: 3.58, 95% CI: -3.92, 11.08, P > 0.05), insulin (WMD: -0.19, 95% CI: -1.63, 1.25, P > 0.05), and HOMA-IR (WMD: 0.25, 95% CI: -0.55, 1.06, P > 0.05).

CONCLUSION

The sum up, incorporating cashew into the diet has no significant effect on body composition or modifying glycemic indices.

The effect of Bertholletia excelsa on body weight, cholestrol, and c-reactive protein: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND & OBJECTIVE(S)

Bertholletia excelsa is a rich herbal source of anti-oxidants and phenols. The goal of this study is to evaluation the effect of bertholletia excelsa nut on body weight, C-reactive protein (CRP) and lipid profile.

METHODS

A literature search was conducted in PubMed, Scopus and Web of sciences databases by two reviewers up to October 2019. Random effect model used to combine results.

RESULTS

Six studies included in analysis with 71 participants. The population was public population. Pooled results showed Bertholletia excelsa have reduction effect on triglyceride weighted mean difference (WMD: -8.23 mg/dl, 95 % CI -15.09, -1.38, I² = 0%), Cholesterol (WMD: -14.31 mg/dl, 95 % CI -23.38, -5.24, I² = 47 %), Low-density lipoprotein (LDL) (WMD: -9.27 mg/dl, 95 % CI -13.48, -5.06, I² = 0%).

CONCLUSION

This study provided an evidence that Bertholletia excelsa nuts have reduction effect on triglyceride, cholesterol, and LDL levels.

Nuts

Nuts are fruits composed of two parts: an inedible hard shell and an edible seed. Nuts are known as an energy-dense and nutrient-rich food source. In general, nuts are recognized as a good source of fat, fiber, and protein. Nuts are extremely beneficial parts of any diet since their consumption may lower risk for some diseases, such as cardiovascular diseases and cancer. They are acknowledged for their low glycemic index owning to high unsaturated fat and protein content and relatively low carbohydrate content. They have been shown to increase cognitive function as well.

Assessment of growth and productivity of five peanut cultivars and genetic diversity using RAPD markers

Background

This study was conducted to evaluate the genetic diversity of five peanut cultivars grown under field conditions. A field experiment was conducted using five peanut cultivars (Giza-5, Giza-6, Ismailia-1, Gregory, and R92) in a randomized complete block design with five replications during two following seasons to estimate the performance of five peanut cultivars for vegetative growth, yield, and yield component traits as well as seed quality traits. Twenty RAPD primers were used to identify a unique fingerprint for each of five cultivars.

Results

Giza-6 cultivar surpassed all the tested peanut cultivars in the most vegetative growth traits and yield and its components traits, while the lowest values were observed in Giza-5 cultivar. The dendrogram constructed from RAPD analysis showed that Gregory and Giza-5 were the most distant among five peanut cultivars.

Conclusions

RAPD markers are useful in the detection of genetic diversity of peanut. The availability of genetic diversity is important for the genetic improvement of peanut.

Dietary Supplementation with Hazelnut Oil Reduces Serum Hyperlipidemia and Ameliorates the Progression of Nonalcoholic Fatty Liver Disease in Hamsters Fed a High-Cholesterol Diet

Objective: Hazelnut oil (HO) is rich in monounsaturated fatty acids and polyunsaturated fatty acids. This study intended to analyze the effects of hazelnut oil supplementation on the serum lipid profile and nonalcoholic fatty liver disease in hamsters fed a high-cholesterol (HC) diet. Methods: Hamsters were fed a basic diet (control group) and an HC diet (HC group) for 16 weeks (n = 10 in each group). Hamsters were fed an HC diet for four weeks to induce hyperlipidemia and were then fed an HC diet enriched with 5% (low-dose HC + HO group; n = 10) and 10% HO (high-dose HC + HO group; n = 10) for 12 weeks. Serum lipid levels, hepatic changes (including steatosis, inflammation, and fibrosis), and hepatic prooxidant-antioxidant status (malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPx), and glutathione S-transferase (GST)) were evaluated after the treatment period. Results: Hamsters in the control group showed normal serum lipid profiles, normal liver function, and moderate glycogen storage without hepatic steatosis. Hamsters in the HC group showed severe hyperlipidemia, severe hepatic steatosis, and moderate steatohepatitis (mononuclear cell and neutrophil infiltration, oval cell hyperplasia, and fibrosis). Compared to the HC group, both the low-dose and the high-dose HC + HO groups showed a significant reduction of hyperlipidemia (serum triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and very-low-density lipoprotein cholesterol (VLDL-C levels)) and improved liver function (serum glutamic-oxaloacetic transaminase (SGOT) and serum glutamic pyruvic transaminase (SGPT)). Additionally, compared to the HC group, intrahepatic triglyceride accumulation (IHTC) was significantly higher in the HC + HO group, while the incidence of steatohepatitis was significantly lower. The intake of the HC diet was associated with a higher level of lipid peroxidation (malondialdehyde, MDA) and a lower concentration of hepatic antioxidant enzymes (SOD, GPx, and GST), and all these factors were partially improved in the low-dose and high-dose HC + HO groups. Conclusions: Our findings indicate that the intake of HO reduced serum hyperlipidemia and oxidative stress and ameliorated the progression of nonalcoholic fatty liver disease in hamsters fed a high-cholesterol diet.

Evaluation of the Influence of Raw Almonds on Appetite Control: Satiation, Satiety, Hedonics and Consumer Perceptions

Snack foods can be substantial contributors to daily energy intake, with different types of snacks exerting potentially different effects on satiety per calorie consumed. The present research compared the effect of consuming almonds as a mid-morning snack compared to an energy and weight-matched comparator snack (savoury crackers) or the equivalent weight of water (zero energy control). In a crossover design, 42 female participants (age: 26.0 ± 7.9, BMI: 22.0 ± 2.0) consumed a fixed breakfast then a mid-morning snack. Appetite, 24-h energy intake, food hedonics, and consumer perceptions of the snack foods were assessed under laboratory conditions. AUC analyses revealed a lower overall hunger drive after consuming almonds compared to crackers or water. There was no difference in 24-h energy intake in the almond compared to the cracker or the zero-energy control condition, however participants consumed more energy in the cracker condition compared to the zero-energy control condition. In addition, almonds suppressed hedonic preference (implicit wanting) for consuming high-fat foods and demonstrated a higher satiety quotient (SQ) than crackers. Almonds were perceived to have a more favourable consumer profile aligned with successful weight management. In conclusion, these findings demonstrate that in the context of a 24-h period of objectively measured energy intake, raw almonds are effective for controlling appetite compared to an energy matched alternative snack. This trial was registered at clinicaltrials.gov [NCT02480582].

Associations of Nut Intakes with Incident Sporadic Colorectal Adenoma: A Pooled Case-Control Study

INTRODUCTION

Consumption of nuts, which contain multiple anti-carcinogenic components, has been inversely associated with colorectal cancer (CRC), particularly among women, but has not been investigated in relation to colorectal adenoma, the immediate precursor to most CRCs.

METHODS

We pooled data from three case-control studies of incident, sporadic colorectal adenoma (n = 785 cases, 2107 controls) in which dietary intakes were assessed using food frequency questionnaires, and analyzed the data using multivariable unconditional logistic regression.

RESULTS

Among men and women combined, the multivariable-adjusted odds ratios (OR) and 95% confidence intervals (CI) for the association of total nut product (all nuts and peanut butter combined) intakes, for those who consumed 0.5-1.5, 2.0-5.5, and ≥6 servings/week relative to no nut consumption were 0.81 (0.58, 1.12), 0.86 (0.61, 1.23), and 0.93 (0.65, 1.31), respectively. However, among women, the corresponding ORs and 95% CIs were 0.62 (0.40, 0.97), 0.57 (0.35, 0.94), and 0.78 (0.48, 1.25), respectively.

CONCLUSIONS

These results suggest that moderate nut consumption may be associated with lower risk for colorectal adenoma, primarily among women.

Nut consumption and metabolic syndrome in US adolescents

OBJECTIVE

To determine whether nut intake is associated with the prevalence of metabolic syndrome in US adolescents.

DESIGN

A cross-sectional analysis of data from the National Health and Nutrition Examination Survey (NHANES) years 2003-2012. Anthropometric measurements, blood tests, 24 h diet recalls and demographic data were retrieved for participating adolescents. Metabolic syndrome was defined according to paediatric-modified Adult Treatment Panel III criteria. The exposure was defined as a nut intake ≥5 g/d.

SETTING

USA.

SUBJECTS

Individuals aged 12-19 years (n 2805).

RESULTS

Nut consumption was associated with lower odds for metabolic syndrome (crude OR=0·25; 95 % CI 0·11, 0·55; P≤0·001). This effect was independent of age, sex, race/ethnicity and family income:poverty ratio (adjusted OR=0·27; 95 % CI 0·12, 0·61; P=0·002), and was stable after controlling for nutritional covariates including intake of sugar and total energy consumption (OR=0·36; 95 % CI 0·16, 0·81; P=0·014).

CONCLUSION

Nut consumption of ≥5 g/d is independently associated with lower odds for metabolic syndrome in US adolescents.

Mediterranean Diet and Health Outcomes in the SUN Cohort

The Mediterranean Dietary (MedDiet) Pattern has been linked to many beneficial health effects. This review summarizes the main findings of a prospective cohort study, the Seguimiento Universidad de Navarra (SUN) cohort, specifically focused on MedDiet and the risk of major chronic disease. It is an open cohort in which 22,786 Spanish university graduates have participated since 1999 until February 2018. Data on diet, lifestyle and clinical diagnosis are collected at baseline and every two years. After reviewing 21 publications from the SUN cohort on the effects of the MedDiet, we conclude that this cohort has provided good evidence that a high MedDiet adherence is associated with a reduced incidence of all-cause mortality, fatal and non-fatal major cardiovascular disease (CVD), type 2 diabetes, weight gain, metabolic syndrome, depression, cognitive decline, and nephrolithiasis. An inverse dose-response relationship was found for many of these associations. The MedDiet was also associated with lower average heart rate, a mitigation of the harmful effects of overweight/obesity on the risk of CVD, and an attenuation of the effects of obesity on type 2 diabetes. A suggestion that the MedDiet may enhance fertility was also found.

Understanding the Effect of Particle Size and Processing on Almond Lipid Bioaccessibility through Microstructural Analysis: From Mastication to Faecal Collection

We have previously reported on the low lipid bioaccessibility from almond seeds during digestion in the upper gastrointestinal tract (GIT). In the present study, we quantified the lipid released during artificial mastication from four almond meals: natural raw almonds (NA), roasted almonds (RA), roasted diced almonds (DA) and almond butter from roasted almonds (AB). Lipid release after mastication (8.9% from NA, 11.8% from RA, 12.4% from DA and 6.2% from AB) was used to validate our theoretical mathematical model of lipid bioaccessibility. The total lipid potentially available for digestion in AB was 94.0%, which included the freely available lipid resulting from the initial sample processing and the further small amount of lipid released from the intact almond particles during mastication. Particle size distributions measured after mastication in NA, RA and DA showed most of the particles had a size of 1000 µm and above, whereas AB bolus mainly contained small particles (<850 µm). Microstructural analysis of faecal samples from volunteers consuming NA, RA, DA and AB confirmed that some lipid in NA, RA and DA remained encapsulated within the plant tissue throughout digestion, whereas almost complete digestion was observed in the AB sample. We conclude that the structure and particle size of the almond meals are the main factors in regulating lipid bioaccessibility in the gut.

Food processing and structure impact the metabolizable energy of almonds

The measured metabolizable energy (ME) of whole almonds has been shown to be less than predicted by Atwater factors. However, data are lacking on the effects of processing (roasting, chopping or grinding) on the ME of almonds. A 5-period randomized, crossover study in healthy individuals (n = 18) was conducted to measure the ME of different forms of almonds (42 g per day), as part of a controlled diet: whole, natural almonds; whole, roasted almonds; chopped almonds; almond butter; and control (0 g per day). After 9 days of adaptation to each diet, participants collected all urine and fecal samples for 9 days. Diets, urine, and feces were analyzed to determine ME. Fracture force and fracture properties of whole and chopped almonds were measured. Measured ME (kcal g^-1) of whole natural almonds (4.42), whole roasted almonds (4.86), and chopped almonds (5.04) was significantly lower than predicted with Atwater factors (P < 0.001); ME of almond butter (6.53 kcal g^-1) was similar to predicted (P = 0.08). The ME of whole roasted and chopped almonds was lower than almond butter (P < 0.0001). ME of whole natural almonds was lower than whole roasted almonds (P < 0.05). This may be due to lower hardness of whole roasted (298 ± 1.3 N) compared to whole natural almonds (345 ± 1.6 N) (P < 0.05), and to whole natural almonds fracturing into fewer, larger particles, thus inhibiting the release of lipids. Atwater factors overestimate the ME of whole (natural and roasted) and chopped almonds. The amount of calories absorbed from almonds is dependent on the form in which they are consumed.

Favourable nutrient intake and displacement with long-term walnut supplementation among elderly: results of a randomised trial

Older adults tend to require fewer energy content and higher levels of nutrients to promote and maintain optimal health. Regrettably, dietary variety and quality are known to decline with advancing age. We conducted a 2-year prospective, randomised, dietary intervention trial where we asked free-living elderly subjects (63-79 years) on self-selected habitual diets to incorporate walnuts daily into their diet (15 % energy). We then compared their nutrient intake with that of a similar group of concurrent participants on self-selected habitual diets but abstaining from walnut consumption (control). No recipes or advice on use of nuts were provided. Dietary intake was assessed by multiple unannounced 24-h telephone dietary recalls. On average, walnut supplement consumption was 43 g/d or 1171·5 kJ (281 kcal). The mean daily energy intake was 954 kJ (228 kcal) higher in the walnut group than in the control group (P<0·001). Compared with control, participants in the walnut group reported significantly higher intake of total protein, vegetable protein, total PUFA and n-3 and n-6 PUFA; and significantly lower intake of total carbohydrate, animal protein, SFA, and Na. An estimated 19 % of total energy and 25 % of total fat from other food sources was displaced. Displacement of MUFA and total PUFA was 21 and 16 %, respectively. Thus adding a daily supplement of walnuts to an ad libitum diet of older adults can induce favourable modifications to the nutrient profile in a way that addresses declining nutrient intake associated with aging.

Metabolic and Blood Pressure Effects of Walnut Supplementation in a Mouse Model of the Metabolic Syndrome

There is extensive evidence that walnut consumption is protective against cardiovascular disease and diabetes in the healthy population, but the beneficial effects of walnut consumption in individuals with the metabolic syndrome (MetS) remain uncertain. We compared a range of cardio-metabolic traits and related tissue gene expression associated with 21 weeks of dietary walnut supplementation in a mouse model of MetS (MetS-Tg) and wild-type (WT) mice (n = 10 per genotype per diet, equal males and females). Compared to standard diet, walnuts did not significantly alter food consumption or body weight trajectory of either MetS-Tg or WT mice. In MetS-Tg mice, walnuts were associated with reductions in oral glucose area under the curve (gAUC, standard diet 1455 ± 54, walnut 1146 ± 91, p = 0.006) and mean arterial blood pressure (MAP, standard diet 100.6 ± 1.9, walnut 73.2 ± 1.8 mmHg, p < 0.001), with neutral effects on gAUC and MAP in WT mice. However, in MetS-Tg mice, walnuts were also associated with trends for higher plasma cholesterol (standard diet 4.73 ± 0.18, walnut 7.03 ± 1.99 mmol/L, p = 0.140) and triglyceride levels (standard diet 2.4 ± 0.5, walnut 5.4 ± 1.6 mmol/L, p = 0.061), despite lowering cholesterol and having no effect on triglycerides in WT mice. Moreover, in both MetS-Tg and WT mice, walnuts were associated with significantly increased liver expression of genes associated with metabolism (Fabp1, Insr), cell stress (Atf6, Ddit3, Eif2ak3), fibrosis (Hgf, Sp1, Timp1) and inflammation (Tnf, Ptpn22, Pparg). In conclusion, dietary walnuts were associated with modest favourable effects in WT mice, but a combination of beneficial and adverse effects in MetS-Tg mice, and up-regulation of hepatic pro-fibrotic and pro-inflammatory genes in both mouse strains.

Palm oil and cardiovascular disease: a randomized trial of the effects of hybrid palm oil supplementation on human plasma lipid patterns

This study examines, for the first time, the effect of hybrid Elaeis oleifera × E. guineensis palm oil supplementation on human plasma lipids related to CVD risk factors. One hundred sixty eligible participants were randomized and assigned to one of the two treatments: 25 mL hybrid palm oil (HPO group) or 25 mL extra virgin olive oil (EVOO group) daily for 3 months. Fasting venous samples were obtained at baseline and after 1, 2 and 3 months for measurement of plasma lipids (TC, LDL-C, HDL-C and TAGs). Changes in body mass index and waist circumference were also assessed. Although there was an overall reduction in TC (7.4%, p < 0.001) and in LDL-C (15.6%, p < 0.001), no significant differences were found between the treatment groups in a repeated measures analysis of variance for TC (p = 0.0525), LDL-C (p = 0.2356), HDL-C (p = 0.8293) or TAGs (p = 0.3749). Furthermore, HPO consumption had similar effects on plasma lipids to EVOO, thus providing additional support for the concept that hybrid Elaeis oleifera × E. guineensis palm oil can be seen as a "tropical equivalent of olive oil".

Associations between nut consumption and inflammatory biomarkers

BACKGROUND

Increased nut consumption has been associated with reduced risk of cardiovascular disease and type 2 diabetes, as well as a healthy lipid profile. However, the associations between nut consumption and inflammatory biomarkers are unclear.

OBJECTIVE

We investigated habitual nut consumption in relation to inflammatory biomarkers in 2 large cohorts of US men and women.

DESIGN

We analyzed cross-sectional data from 5013 participants in the Nurses' Health Study (NHS) and Health Professionals Follow-Up Study (HPFS) who were free of diabetes. Nut intake, defined as intake of peanuts and other nuts, was estimated from food-frequency questionnaires, and cumulative averages from 1986 and 1990 in the NHS and from 1990 and 1994 in the HPFS were used. Plasma biomarkers were collected in 1989-1990 in the NHS and 1993-1995 in the HPFS. Multivariate linear regression was used to assess the associations of nut consumption with fasting plasma C-reactive protein (CRP, n = 4941), interleukin 6 (IL-6, n = 2859), and tumor necrosis factor receptor 2 (TNFR2, n = 2905).

RESULTS

A greater intake of nuts was associated with lower amounts of a subset of inflammatory biomarkers, after adjusting for demographic, medical, dietary, and lifestyle variables. The relative concentrations (ratios) and 95% CIs comparing subjects with nut intake of ≥5 times/wk and those in the categories of never or almost never were as follows: CRP: 0.80 (0.69, 0.90), P-trend = 0.0003; and IL-6: 0.86 (0.77, 0.97), P-trend = 0.006. These associations remained significant after further adjustment for body mass index. No significant association was observed with TNFR2. Substituting 3 servings of nuts/wk for 3 servings of red meat, processed meat, eggs, or refined grains/wk was associated with significantly lower CRP (all P < 0.0001) and IL-6 (P ranges from 0.001 to 0.017).

CONCLUSION

Frequent nut consumption was associated with a healthy profile of inflammatory biomarkers.

A Randomized Controlled Trial of the Effects of an Almond-enriched, Hypocaloric Diet on Liver Function Tests in Overweight/Obese Women

Background:

Gradual weight reduction has been shown to be associated with improvements in liver enzymes. However, some evidence demonstrated that liver enzymes may transiently increase immediately after a diet-induced weight loss.

Objectives:

This study was designed to assess the effects of a hypocaloric, almond-enriched diet (AED) compared with a hypocaloric nut-free diet (NFD) on liver function tests in the context of a three-month weight reduction program in overweight/obese women.

Patients and Methods:

This randomized controlled clinical trial was registered at Iranian Registry of Clinical Trials with ID number of IRCT2013062313751N1. Overweight and obese Iranian women [n = 108; age = 42.7 y, body mass index = 29.6 kg/m²] were randomly assigned to consume an AED or NFD. The carefully planned hypocaloric diets were identical for both groups except for the AED group who consumed 50 grams of almonds daily for three months. Anthropometric measurements and laboratory measurements including alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and γ-glutamyltransferase (GGT) were assessed before and immediately after the intervention.

Results:

Of 108 participants, 50 women in AED group and 50 women in NFD group completed the protocol of the study (response rate: 92.6 %). The AED led to a median weight loss of 3.79 kg (interquartile range: 4.4 kg). Significant decreases within AED and NFD were observed in ALT (-16.6 ± 16.3 and -11.7 ± 16.8, P < 0.001, respectively). Similar significant decreases were observed in AST (-13.6 ± 15.7 and -7.7 ± 16.1; P < 0.001, respectively). The decrease in GGT was also significant in both groups (-11.4 ± 21.6 and -6.2 ± 19.8; P < 0.001 respectively). ALT, AST and GGT decreased significantly in the AED group compared to the NFD group (P < 0.001).

Conclusions:

AED improved liver enzymes in obese women. However, mild, transient increases in ALT and AST values can be observed immediately after an NFD in women.

Walnuts Consumed by Healthy Adults Provide Less Available Energy than Predicted by the Atwater Factors

BACKGROUND

Previous studies have shown that the metabolizable energy (ME) content (energy available to the body) of certain nuts is less than predicted by the Atwater factors. However, very few nuts have been investigated to date, and no information is available regarding the ME of walnuts.

OBJECTIVE

A study was conducted to determine the ME of walnuts when consumed as part of a typical American diet.

METHODS

Healthy adults (n = 18; mean age = 53.1 y; body mass index = 28.8 kg/m(2)) participated in a randomized crossover study with 2 treatment periods (3 wk each). The study was a fully controlled dietary feeding intervention in which the same base diet was consumed during each treatment period; the base diet was unsupplemented during one feeding period and supplemented with 42 g walnuts/d during the other feeding period. Base diet foods were reduced in equal proportions during the walnut period to achieve isocaloric food intake during the 2 periods. After a 9 d diet acclimation period, subjects collected all urine and feces for ∼1 wk (as marked by a Brilliant Blue fecal collection marker) for analysis of energy content. Administered diets, walnuts, and fecal and urine samples were subjected to bomb calorimetry, and the resulting data were used to calculate the ME of the walnuts.

RESULTS

One 28-g serving of walnuts contained 146 kcal (5.22 kcal/g), 39 kcal/serving less than the calculated value of 185 kcal/serving (6.61 kcal/g). The ME of the walnuts was 21% less than that predicted by the Atwater factors (P < 0.0001).

CONCLUSION

Consistent with other tree nuts, Atwater factors overestimate the metabolizable energy value of walnuts. These results could help explain the observations that consumers of nuts do not gain excessive weight and could improve the accuracy of food labeling. This trial was registered at clinicaltrials.gov as NCT01832909.

Inverse association between the frequency of nut consumption and obesity among Iranian population: Isfahan Healthy Heart Program

PURPOSE

Recently, controversies have arisen concerning the association between nut intake and obesity. This study was performed to investigate the relationship between nut consumption and obesity among Iranian adults.

METHODS

In a cross-sectional survey, 9,660 randomly chosen adults aged ≥19 years were selected based on gender, age and their settlement distributions in three districts of central Iran in 2007. Nutritional behaviors including regular intake of walnuts, almonds, pistachios, hazelnuts and sunflower seed were assessed by validated 48-item-food-frequency questionnaire and a 24-h recall questionnaire. Using hierarchical logistic regression test, odds ratio (OR) 95% CI of obesity based on nut consumption was determined in an unadjusted and four adjusted models.

RESULTS

The results showed a significant association between high nut consumption and lower prevalence of overweight or general obesity as well as abdominal obesity in women (p = 0.01 and p = 0.047, respectively), but not men. The frequency of nut consumption was associated with lower risk of overweight or general obesity [OR (95% CI) 0.57 (0.38-0.86)] and abdominal obesity [OR (95% CI) 0.51 (0.28-0.95)] only in women. After adjusting for gender, age and other potential confounders, the strength of the associations was blunted, but they were still significant.

CONCLUSIONS

Frequent nuts and seeds consumption, particularly ≥1 time/day, had an inverse association with all classes of obesity among women.

A mid-morning snack of almonds generates satiety and appropriate adjustment of subsequent food intake in healthy women

PURPOSE

To assess the effect of consuming a mid-morning almond snack (28 and 42 g) tested against a negative control of no almonds on acute satiety responses.

METHOD

On three test days, 32 healthy females consumed a standard breakfast followed by 0, 28 or 42 g of almonds as a mid-morning snack and then ad libitum meals at lunch and dinner. The effect of the almond snacks on satiety was assessed by measuring energy intake (kcal) at the two ad libitum meals and subjective appetite ratings (visual analogue scales) throughout the test days.

RESULTS

Intake at lunch and dinner significantly decreased in a dose-dependent manner in response to the almond snacks. Overall, a similar amount of energy was consumed on all three test days indicating that participants compensated for the 173 and 259 kcals consumed as almonds on the 28 and 42 g test days, respectively. Subjective appetite ratings in the interval between the mid-morning snack and lunch were consistent with dose-dependent enhanced satiety following the almond snacks. However, in the interval between lunch and dinner, appetite ratings were not dependent on the mid-morning snack.

CONCLUSION

Almonds might be a healthy snack option since their acute satiating effects are likely to result in no net increase in energy consumed over a day.

Long-term associations of nut consumption with body weight and obesity

There is some concern that the high-fat, energy-dense content of nuts may promote weight gain. Nuts, however, are rich in protein and dietary fiber, which are associated with increased satiety. They also contain high amounts of vitamins, minerals, antioxidants, and phytoesterols that may confer health benefits for cardiovascular disease and type 2 diabetes delay and prevention. Therefore, it is important to determine the association between nut consumption and long-term weight change and disease risk to reach scientific consensus and to make evidence-based public health recommendations. Several cross-sectional analyses have shown an inverse association between higher nut consumption and lower body weight. In addition, several independent prospective studies found that increasing nut consumption was associated with lower weight gain over relatively long periods of time. Moreover, high consumption of nuts (especially walnuts) has been associated with lower diabetes risk. Therefore, regular consumption (approximately one handful daily) of nuts over the long term, as a replacement to less healthful foods, can be incorporated as a component of a healthy diet for the prevention of obesity and type 2 diabetes.

Appetitive, dietary and health effects of almonds consumed with meals or as snacks: a randomized, controlled trial

BACKGROUND/OBJECTIVES

Snacks contribute toward a significant proportion of human total daily energy intake. This study investigated the effects of almonds, a satiating and nutrient-rich, common snack, on postprandial glycemia, appetite, short-term body weight and fasting blood parameters when consumed with meals or alone as a snack.

METHODS

This was a 4-week randomized, parallel-arm study that entailed consuming almonds (43 g/day) with breakfast (BF) or lunch (LN), alone as a morning (MS) or afternoon (AS) snack or no almonds (CL). Participants (N=137) with increased risk for type 2 diabetes completed an oral glucose tolerance test (OGTT) and acute-feeding session at baseline, followed by almond consumption for 4 weeks before repeating the OGTT and acute-feeding trials. Anthropometric, biochemical and appetite responses were assessed.

RESULTS

Almonds lowered serum glucose responses postprandially. Effects were most prominent in the snack groups. Almonds, consumed as snacks, also reduced hunger and desire to eat during the acute-feeding session. After 4 weeks, anthropometric measurements and fasting blood biochemistries did not differ from the control group or across intervention groups. Without specific guidance, daily energy intake was reduced to compensate for energy from the provided almonds. Dietary monounsaturated fat and α-tocopherol intakes were significantly increased in all almond groups.

CONCLUSION

Almonds provide post-ingestive metabolic and appetitive benefits and did not increase the risk for weight gain. This suggests that almonds may be a healthful snack option.

Peanut consumption in adolescents is associated with improved weight status

Studies have shown an association between nut consumption and health benefits in adults such as lower lipid levels, lower body mass indices, and reduced risk of coronary artery disease. Few studies have demonstrated these health benefits in children. To determine the association between peanut consumption and weight, intake of nutrients of concern, high-density lipoprotein, low-density lipoprotein, and cholesterol in Mexican American children, baseline data from 262 sixth-grade students (48% female) in a school-based weight management program were analyzed to compare differences between peanut and non-peanut eaters. It was hypothesized that Mexican American children who consume peanuts will be less overweight and have a better nutrient and lipid profile when compared to those who do not eat peanuts. Participants completed a food frequency questionnaire as a baseline dietary assessment before beginning the program. Children were identified as either a peanut consumer (n = 100) or non-peanut consumer (n = 162). Body mass index measurements were taken on all participants. A smaller sample of participants submitted blood for lipid analysis. Analyses revealed that children in the peanut consumer group were less likely to be overweight or obese than children in the non-peanut consumer group (χ(2) = 13.9, P = .001), had significantly higher intakes of several vitamins and micronutrients (i.e., magnesium, vitamin E), and had lower low-density lipoprotein and total cholesterol levels. These results illustrate that consumption of peanuts and/or peanut butter is associated with lower weight status, improved diet, and lipid levels among Mexican American children. Future research is needed to clarify the role of peanut consumption in children's overall health.

Chemical composition of nuts and seeds sold in Korea

Eleven types of nuts and seeds were analyzed to determine their energy (326-733 mg), moisture (1.6-18.3 mg), carbohydrate (8.8-70.9 mg), protein (4.9-30.5 mg), lipid (2.5-69.8 mg), and ash (1.2-5.5 mg) contents per 100 g of sample. Energy content was highest in pine nuts (733 mg/100 g), carbohydrate level was highest in dried figs (70.9 mg/100 g) and protein was highest in peanuts (30.5 mg/100 g). The amino acid compositions of nuts and seeds were characterized by the dominance of hydrophobic (range = 1,348.6-10,284.6 mg), hydrophilic (range = 341.1-3,244.3 mg), acidic (range = 956.1-8,426.5 mg), and basic (range = 408.6-4,738.5 mg) amino acids. Monounsaturated fatty acids (MUFA) were highest in macadamia nuts (81.3%), whereas polyunsaturated fatty acids (PUFA) were highest in the walnuts (76.7%). Macadamia nuts did not contain any vitamin E, whereas sunflower seeds contained the highest level (60.3 mg/kg). Iron (Fe) content was highest in pumpkin seeds (95.85 ± 33.01 ppm), zinc (Zn) content was highest in pistachios (67.24 ± 30.25 ppm), copper (Cu) content was greatest in walnuts (25.45 ± 21.51 ppm), and lead (Pb) content was greatest in wheat nuts (25.49 ± 4.64 ppm), significantly (P < 0.05). In conclusion, current commercial nuts and seeds have no safety concerns, although further analysis of Pb contents is necessary to ensure safety.

The effect of peanut and grain bar preloads on postmeal satiety, glycemia, and weight loss in healthy individuals: an acute and a chronic randomized intervention trial

BACKGROUND

Peanut consumption favorably influences satiety. This study examined the acute effect of peanut versus grain bar preloads on postmeal satiety and glycemia in healthy adults and the long-term effect of these meal preloads on body mass in healthy overweight adults.

METHODS

In the acute crossover trial (n = 15; 28.4 ± 2.9 y; 23.1 ± 0.9 kg/m2), the preload (isoenergetic peanut or grain bar with water, or water alone) was followed after 60 min with ingestion of a standardized glycemic test meal. Satiety and blood glucose were assessed immediately prior to the preload and to the test meal, and for two hours postmeal at 30-min intervals. In the parallel-arm, randomized trial (n = 44; 40.5 ± 1.6 y, 31.8 ± 0.9 kg/m2), the peanut or grain bar preload was consumed one hour prior to the evening meal for eight weeks. Body mass was measured at 2-week intervals, and secondary endpoints included blood hemoglobin A1c and energy intake as assessed by 3-d diet records collected at pre-trial and trial weeks 1 and 8.

RESULTS

Satiety was elevated in the postprandial period following grain bar ingestion in comparison to peanut or water ingestion (p = 0.001, repeated-measures ANOVA). Blood glucose was elevated one hour after ingestion of the grain bar as compared to the peanut or water treatments; yet, total glycemia did not vary between treatments in the two hour postprandial period. In the 8-week trial, body mass was reduced for the grain bar versus peanut groups after eight weeks (-1.3 ± 0.4 kg versus -0.2 ± 0.3 kg, p = 0.033, analysis of covariance). Energy intake was reduced by 458 kcal/d in the first week of the trial for the grain bar group as compared to the peanut group (p = 0.118). Hemoglobin A1c changed significantly between groups during the trial (-0.25 ± 0.07% and -0.18 ± 0.12% for the grain bar and peanut groups respectively, p = 0.001).

CONCLUSIONS

Compared to an isoenergetic peanut preload, consumption of a grain bar preload one hour prior to a standardized meal significantly raised postmeal satiety. Moreover, consumption of the grain bar prior to the evening meal was associated with significant weight loss over time suggesting that glycemic carbohydrate ingestion prior to meals may be a weight management strategy.

Health benefits of nut consumption with special reference to body weight control

Nuts are an integral part of the Mediterranean food patterns, and their incorporation into the regular diets of human beings is believed to provide many health benefits. The recent recognition of nuts as "heart-healthy" foods by the U.S. Food and Drug Administration has given a major boost to the positive image of nuts. Nut consumption has been associated with several health benefits, such as antioxidant, hypocholesterolemic, cardioprotective, anticancer, anti-inflammatory, and antidiabetic benefits, among other functional properties. However, although nuts possess these many health benefits, their consumption has been hampered by a lack of adequate information regarding those benefits. In addition, because nuts are energy-dense foods with high-fat content, there is a misconception among consumers that increased consumption may lead to unwanted gain in body weight with the risk of developing overweight/obesity. Nonetheless, available epidemiologic studies and short-term controlled feeding trials have supported the theory that the inclusion of nuts in the typical diet does not induce weight gain, despite an expected increase in total caloric intake. To address the misperception about nuts and body weight gain, the present review focuses mainly on the relation between nut consumption and body weight gain, in the context of the many health benefits of nuts.

Dietary macronutrients and food consumption as determinants of long-term weight change in adult populations: a systematic literature review

This systematic literature review examined the role of dietary macronutrient composition, food consumption and dietary patterns in predicting weight or waist circumference (WC) change, with and without prior weight reduction. The literature search covered year 2000 and onwards. Prospective cohort studies, case–control studies and interventions were included. The studies had adult (18–70 y), mostly Caucasian participants. Out of a total of 1,517 abstracts, 119 full papers were identified as potentially relevant. After a careful scrutiny, 50 papers were quality graded as A (highest), B or C. Forty-three papers with grading A or B were included in evidence grading, which was done separately for all exposure-outcome combinations. The grade of evidence was classified as convincing, probable, suggestive or no conclusion. We found probable evidence for high intake of dietary fibre and nuts predicting less weight gain, and for high intake of meat in predicting more weight gain. Suggestive evidence was found for a protective role against increasing weight from whole grains, cereal fibre, high-fat dairy products and high scores in an index describing a prudent dietary pattern. Likewise, there was suggestive evidence for both fibre and fruit intake in protection against larger increases in WC. Also suggestive evidence was found for high intake of refined grains, and sweets and desserts in predicting more weight gain, and for refined (white) bread and high energy density in predicting larger increases in WC. The results suggested that the proportion of macronutrients in the diet was not important in predicting changes in weight or WC. In contrast, plenty of fibre-rich foods and dairy products, and less refined grains, meat and sugar-rich foods and drinks were associated with less weight gain in prospective cohort studies. The results on the role of dietary macronutrient composition in prevention of weight regain (after prior weight loss) were inconclusive.

Discrepancy between the Atwater factor predicted and empirically measured energy values of almonds in human diets

BACKGROUND

The energy content of foods is primarily determined by the Atwater factors, which may not be accurate for certain food groups. Nuts are a food group for which substantial evidence suggests that the Atwater factors may be poorly predictive.

OBJECTIVE

A study was conducted to determine the energy value of almonds in the human diet and to compare the measured energy value with the value calculated from the Atwater factors.

DESIGN

Eighteen healthy adults consumed a controlled diet or an almond-containing diet for 18 d. Three treatments were administered to subjects in a crossover design, and diets contained 1 of 3 almond doses: 0, 42, or 84 g/d. During the final 9 d of the treatment period, volunteers collected all urine and feces, and samples of diets, feces, and urine were analyzed for macronutrient and energy contents. The metabolizable energy content of the almonds was determined.

RESULTS

The energy content of almonds in the human diet was found to be 4.6 ± 0.8 kcal/g, which is equivalent to 129 kcal/28-g serving. This is significantly less than the energy density of 6.0-6.1 kcal/g as determined by the Atwater factors, which is equivalent to an energy content of 168-170 kcal/serving. The Atwater factors, when applied to almonds, resulted in a 32% overestimation of their measured energy content.

CONCLUSION

This study provides evidence for the inaccuracies of the Atwater factors for certain applications and provides a rigorous method for determining empirically the energy value of individual foods within the context of a mixed diet. This trial was registered at clinicaltrials.gov as NCT01007188.

A randomized trial of the effects of an almond-enriched, hypocaloric diet in the treatment of obesity

BACKGROUND

Increased consumption of nuts has been advocated because of their health benefits, but the role of nuts in the treatment of obesity is unclear given their high energy density.

OBJECTIVE

This study was designed to evaluate the effects of a hypocaloric, almond-enriched diet (AED) compared with a hypocaloric nut-free diet (NFD) on body weight and cardiovascular disease risk factors in the context of an 18-mo behavioral weight-management program.

DESIGN

Overweight and obese individuals [n = 123; age = 46.8 y, BMI (in kg/m(2)) = 34.0] were randomly assigned to consume an AED or NFD and instructed in traditional behavioral methods of weight control. Anthropometric and metabolic measurements were made at baseline, 6 mo, and 18 mo.

RESULTS

Those in the AED group lost slightly but significantly less weight than did those in the NFD group at 6 mo (-5.5 compared with -7.4 kg; P = 0.04), but there were no differences at 18 mo. No significant differences in body composition were found between the groups at 6 or 18 mo. The AED, compared with the NFD, was associated with greater reductions in total cholesterol (P = 0.03), total:HDL cholesterol (P = 0.02), and triglycerides (P = 0.048) at 6 mo, and no differences were observed between the groups at 18 mo.

CONCLUSIONS

The AED and NFD groups experienced clinically significant and comparable weight loss at 18 mo. Despite smaller weight loss in the AED group at 6 mo, the AED group experienced greater improvements in lipid profiles. This trial was registered at clinicaltrials.gov as NCT00194428.

Health benefits of almonds beyond cholesterol reduction

Almonds are rich in monounsaturated fat, fiber, α-tocopherol, minerals such as magnesium and copper, and phytonutrients, albeit being energy-dense. The favorable fat composition and fiber contribute to the hypocholesterolemic benefit of almond consumption. By virtue of their unique nutrient composition, almonds are likely to benefit other modifiable cardiovascular and diabetes risks, such as body weight, glucose homeostasis, inflammation, and oxidative stress. This paper briefly reviews the nutrient composition and hypocholesterolemic benefits; the effects of almond consumption on body weight, glucose regulation, oxidative stress, and inflammation, based on the data of clinical trials, will then be discussed. Although more studies are definitely warranted, the emerging evidence supports that almond consumption beneficially influences chronic degenerative disease risk beyond cholesterol reduction, particularly in populations with metabolic syndrome and type 2 diabetes mellitus.

Nuts as a replacement for carbohydrates in the diabetic diet

OBJECTIVE

Fat intake, especially monounsaturated fatty acid (MUFA), has been liberalized in diabetic diets to preserve HDL cholesterol and improve glycemic control, yet the exact sources have not been clearly defined. Therefore, we assessed the effect of mixed nut consumption as a source of vegetable fat on serum lipids and HbA(1c) in type 2 diabetes.

RESEARCH DESIGN AND METHODS

A total of 117 type 2 diabetic subjects were randomized to one of three treatments for 3 months. Supplements were provided at 475 kcal per 2,000-kcal diet as mixed nuts (75 g/day), muffins, or half portions of both. The primary outcome was change in HbA(1c).

RESULTS

The relative increase in MUFAs was 8.7% energy on the full-nut dose compared with muffins. Using an intention-to-treat analysis (n = 117), full-nut dose (mean intake 73 g/day) reduced HbA(1c) (-0.21% absolute HbA(1c) units, 95% CI -0.30 to -0.11, P < 0.001) with no change after half-nut dose or muffin. Full-nut dose was significantly different from half-nut dose (P = 0.004) and muffin (P = 0.001), but no difference was seen between half-nut dose and muffins. LDL cholesterol also decreased significantly after full-nut dose compared with muffin. The LDL cholesterol reduction after half-nut dose was intermediate and not significantly different from the other treatments. Apolipoprotein (apo) B and the apoB:apoA1 ratio behaved similarly. Nut intake related negatively to changes in HbA(1c) (r = -0.20, P = 0.033) and LDL cholesterol (r = -0.24, P = 0.011).

CONCLUSIONS

Two ounces of nuts daily as a replacement for carbohydrate foods improved both glycemic control and serum lipids in type 2 diabetes.

Dietary walnut suppressed mammary gland tumorigenesis in the C(3)1 TAg mouse

Walnuts contain multiple ingredients that, individually, have been shown to slow cancer growth, including omega-3 fatty acids, antioxidants, and phytosterols. In previous research, consumption of walnuts has slowed the growth of implanted breast cancers. We wanted to determine whether regular walnut consumption might reduce the risk for developing cancer. Homozygous male C(3)1 TAg mice were bred with female SV129 mice consuming either the control AIN-76 diet or the walnut-containing diet. At weaning, the female hemizygous pups were randomized to control or walnut-containing diets and followed for tumor development. Compared to a diet without walnuts, consumption of walnuts significantly reduced tumor incidence (fraction of mice with at least one tumor), multiplicity (number of glands with tumor/mouse), and size. Gene expression analyses indicated that consumption of the walnut diet altered expression of multiple genes associated with proliferation and differentiation of mammary epithelial cells. A comparison with another dietary intervention indicated that the omega 3 content alone did not account for the extent of tumor suppression due to the walnut. The results of this study indicate that walnut consumption could contribute to a healthy diet to reduce risk for breast cancer.