Almonds vs complex carbohydrates in a weight reduction program

Glycaemic Response to a Nut-Enriched Diet in Asian Chinese Adults with Normal or High Glycaemia: The Tū Ora RCT

Nut-based products are a good source of high-quality plant protein in addition to mono- and polyunsaturated fatty acids, and may aid low-glycaemic dietary strategies important for the prevention of type 2 diabetes (T2D). In particular, they may be advantageous in populations susceptible to dysglycaemia, such as Asian Chinese. The present study aimed to compare effects of a higher-protein nut bar (HP-NB, also higher in total fibre and unsaturated fats, comprising mixed almonds and peanuts) vs. an isoenergetic higher-carbohydrate cereal bar (HC-CB) within the diet of 101 Chinese adults with overweight and normo- or hyperglycaemia. Ectopic pancreas and liver fat were characterised using magnetic resonance imaging and spectroscopy (MRI/S) as a secondary outcome. Participants were randomized to receive HP-NB or HC-CB daily as a 1 MJ light meal or snack replacement, in addition to healthy eating advice. Anthropometry and clinical indicators of T2D risk were assessed fasted and during an oral glucose tolerance test (OGTT), pre- and post-intervention. No significant difference was observed between diet groups for body weight, body mass index, waist or hip circumference, blood pressure, glucoregulatory markers, lipid profile or inflammatory markers over 12 weeks (all, p > 0.05). No difference was observed between glycaemic subgroups or those with normal versus high ectopic organ fat. Although HP-NB can attenuate postprandial glycaemia following a meal, no effects were observed for either fasting or glucose-mediated outcomes following longer-term inclusion in the habitual diet of Chinese adults with overweight, including at-risk subgroups.

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.

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.

Can different types of tree nuts and peanuts induce varied effects on specific blood lipid parameters? A systematic review and network meta-analysis

Tree nuts and peanuts have shown cardioprotective effects through the modulation of blood lipid levels. Despite the abundance of scientific evidence available, it remains uncertain whether the type of nut consumed influences these changes. The objective of this study was to evaluate and rank the effects of six types of nuts on total cholesterol (total-c), low-density lipoprotein (LDL-c), triglyceride (TG) and high-density lipoprotein (HDL-c) levels through a systematic search of randomized controlled trials (RCTs), a frequentist network meta-analysis (NMA), and the estimation of SUCRA values. A total of 76 RCTs were ultimately analyzed. The total c for pistachios, almond, and walnuts; LDL-c for cashews, walnuts, and almond; and TG for hazelnuts and walnuts significantly decreased, while only peanuts exhibited a significant increase in HDL-c levels. According to the rankings, the most effective type of nut for reducing total cholesterol was pistachio, cashew for LDL-c, hazelnut for TG, and peanut for increasing HDL-c levels. It should be noted that every type of nut analyzed exhibited a significant positive impact on some parameters, and specific types demonstrated enhanced advantages for particular blood lipids. These results endorse the use of personalized nutritional strategies to address and prevent dyslipidemia.Registration: PROSPERO database CRD42021270779.

Almonds vs. carbohydrate snacks in an energy-restricted diet: Weight and cardiometabolic outcomes from a randomized trial

OBJECTIVE

This study evaluated weight and cardiometabolic outcomes after a 3-month energy-restricted diet (-30%) containing almonds (almond-enriched diet [AED]) or containing carbohydrate-rich snacks (nut-free control diet [NFD]) (Phase 1), followed by 6 months of weight maintenance (Phase 2).

METHODS

Participants (25-65 years old) with overweight or obesity (BMI 27.5-34.9 kg/m2 ) were randomly allocated to AED (n = 68) or NFD (n = 72).

RESULTS

Both groups lost weight during Phase 1 (p < 0.001) (mean [SE], -7.0 [0.5] kg AED vs. -7.0 [0.5] kg NFD, p = 0.858) and Phase 2 (p = 0.009) (-1.1 [0.5] kg AED vs. -1.3 [0.6] NFD, p = 0.756), with improvements in percentage lean mass after Phase 2 (4.8% [0.3%], p < 0.001). Reductions occurred in fasting glucose (-0.2 [0.07] mmol/L, p = 0.003), insulin (-8.1 [4.0] pmol/L, p = 0.036), blood pressure (-4.9 [0.8] mm Hg systolic, -5.0 [0.5] mm Hg diastolic, p < 0.001), total cholesterol (-0.3 [0.1] mmol/L), low-density lipoprotein (LDL) (-0.2 [0.1] mmol/L), very low-density lipoprotein (-0.1 [0.03] mmol/L), and triglycerides (-0.3 [0.06] mmol/L) (all p < 0.001), and high-density lipoprotein increased (0.1 [0.02] mmol/L, p = 0.011) by the end of Phase 2 in both groups. There were group by time interactions for lipoprotein particle concentrations: very small triglyceride-rich (-31.0 [7.7] nmol/L AED vs. -4.8 [7.9] nmol/L NFD, p = 0.007), small LDL (-109.3 [40.5] nmol/L AED vs. -20.7 [41.6] nmol/L NFD, p = 0.017), and medium LDL (-24.4 [43.4] nmol/L AED vs. -130.5 [44.4] nmol/L NFD, p = 0.045).

CONCLUSIONS

An energy-restricted AED resulted in weight loss and weight loss maintenance comparable to an energy-restricted NFD, and both diets supported cardiometabolic health. The AED resulted in greater improvements in some lipoprotein subfractions, which may enhance reductions in cardiovascular risk.

Tree Nut and Peanut Consumption and Risk of Cardiovascular Disease: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Cardiovascular disease (CVD) is the leading cause of death globally. Habitual consumption of tree nuts and peanuts is associated with cardioprotective benefits. Food-based dietary guidelines globally recommend nuts as a key component of a healthy diet. This systematic review and meta-analysis were conducted to examine the relationship between tree nut and peanut consumption and risk factors for CVD in randomized controlled trials (RCTs) (PROSPERO: CRD42022309156). MEDLINE, PubMed, CINAHL, and Cochrane Central databases were searched up to 26 September, 2021. All RCT studies that assessed the effects of tree nut or peanut consumption of any dose on CVD risk factors were included. Review Manager software was used to conduct a random effect meta-analysis for CVD outcomes from RCTs. Forest plots were generated for each outcome, between-study heterogeneity was estimated using the I2 test statistic and funnel plots and Egger's test for outcomes with ≥10 strata. The quality assessment used the Health Canada Quality Appraisal Tool, and the certainty of the evidence was assessed using grading of recommendations assessment, development, and evaluation (GRADE). A total of 153 articles describing 139 studies (81 parallel design and 58 cross-over design) were included in the systematic review, with 129 studies in the meta-analysis. The meta-analysis showed a significant decrease for low-density lipoprotein (LDL) cholesterol, total cholesterol (TC), triglycerides (TG), TC:high-density lipoprotein (HDL) cholesterol, LDL cholesterol:HDL cholesterol, and apolipoprotein B (apoB) following nut consumption. However, the quality of evidence was "low" for only 18 intervention studies. The certainty of the body of evidence for TC:HDL cholesterol, LDL cholesterol:HDL cholesterol, and apoB were "moderate" because of inconsistency, for TG were "low," and for LDL cholesterol and TC were "very low" because of inconsistency and the likelihood of publication bias. The findings of this review provide evidence of a combined effect of tree nuts and peanuts on a range of biomarkers to create an overall CVD risk reduction.

Ultraprocessed Foods and Obesity Risk: A Critical Review of Reported Mechanisms

Epidemiologic evidence supports a positive association between ultraprocessed food (UPF) consumption and body mass index. This has led to recommendations to avoid UPFs despite very limited evidence establishing causality. Many mechanisms have been proposed, and this review critically aimed to evaluate selected possibilities for specificity, clarity, and consistency related to food choice (i.e., low cost, shelf-life, food packaging, hyperpalatability, and stimulation of hunger/suppression of fullness); food composition (i.e., macronutrients, food texture, added sugar, fat and salt, energy density, low-calorie sweeteners, and additives); and digestive processes (i.e., oral processing/eating rate, gastric emptying time, gastrointestinal transit time, and microbiome). For some purported mechanisms (e.g., fiber content, texture, gastric emptying, and intestinal transit time), data directly contrasting the effects of UPF and non-UPF intake on the indices of appetite, food intake, and adiposity are available and do not support a unique contribution of UPFs. In other instances, data are not available (e.g., microbiome and food additives) or are insufficient (e.g., packaging, food cost, shelf-life, macronutrient intake, and appetite stimulation) to judge the benefits versus the risks of UPF avoidance. There are yet other evoked mechanisms in which the preponderance of evidence indicates ingredients in UPFs actually moderate body weight (e.g., low-calorie sweetener use for weight management; beverage consumption as it dilutes energy density; and higher fat content because it reduces glycemic responses). Because avoidance of UPFs holds potential adverse effects (e.g., reduced diet quality, increased risk of food poisoning, and food wastage), it is imprudent to make recommendations regarding their role in diets before causality and plausible mechanisms have been verified.

Comparing the effects of consuming almonds or biscuits on body weight in habitual snackers: A one-year randomized controlled trial

PURPOSE

Almonds are nutrient-rich, providing a healthier alternative to many snack foods. Studies report health benefits with regular almond consumption without adverse weight gain. However, most interventions have been relatively short or have included additional dietary advice. Taking a pragmatic approach, we compared consumption of almonds versus biscuits on body weight and other health outcomes in a population of regular snackers of discretionary foods, hypothesizing the almonds will displace some of the less healthful snacks in their current diets.

METHODS

We randomly assigned 136 non-obese habitual discretionary snack consumers to receive almonds or biscuits daily for one-year. These isocaloric snacks provided either 10% of participants' total energy (TE) requirements or 1030 kJ (equivalent to 42.5 g almonds), whichever was greater. Anthropometry, blood biomarkers, diet, appetite, sleep, and, physical activity, were assessed at baseline, 3, 6, and 12 months, and body composition and resting metabolic rate at baseline and 12 months.

RESULTS

The difference in changes for body weight from baseline to 12 months was not statistically significant (geometric means 67.1 kg and 69.5 kg for almonds and 66.3 kg and 66.3 kg for biscuits, P = 0.275). There were no statistically significant differences in changes for body composition or other non-dietary outcomes (all P ≥ 0.112). Absolute intakes of protein; total, polyunsaturated, and monosaturated fat; fibre; vitamin E; calcium; copper; magnesium; phosphorous; and zinc, and % TE from total monounsaturated, and polyunsaturated fat statistically significantly increased from baseline (all P ≤ 0.033), while % TE from carbohydrate and sugar statistically significantly (both P ≤ 0.014) decreased from baseline, in the almond compared to the biscuit group.

CONCLUSIONS

Almonds can be incorporated into the diets of habitual snackers to improve diet quality, without evidence for changes in body weight, compared to a popular discretionary snack food.

TRIAL REGISTRATION

ACTRN12618001758291 https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=375610&isReview=true.

Nutrition and exercise interventions to improve body composition for persons with overweight or obesity near retirement age: A systematic review and network meta-analysis of randomised controlled trials

The retirement phase is an opportunity to integrate healthy (nutrition/exercise) habits into daily life. We conducted this systematic review to assess which nutrition and exercise interventions most effectively improve body composition (fat/muscle mass), body mass index (BMI) and waist circumference (WC) in persons with obesity/overweight near retirement age (ages 55-70). We conducted a systematic review and network-meta-analysis (NMA) of randomised controlled trials, searching four databases from their inception up to 12 July 2022. The NMA was based on a random effects model, pooled mean differences, standardised mean differences, their 95% confidence intervals, and correlations with multi-arm studies. Subgroup and sensitivity analyses were also conducted. 92 studies were included, 66 of which with 4957 participants could be used for the NMA. Identified interventions were clustered into 12 groups: no intervention, energy restriction (i.e. 500-1000 kcal), energy restriction plus high protein (HP) intake (1.1-1.7 g/kg/body weight), intermittent fasting, mixed exercise (aerobic and resistance), resistance training (RT), aerobic training (AT), HP plus RT, energy restriction plus HP plus exercise, energy restriction plus RT, energy restriction plus AT, and energy restriction plus mixed exercise (ME). Intervention durations ranged from 8 weeks to 6 months. Body fat was reduced with energy restriction plus any exercise or plus HP intake. Energy restriction alone was less effective and tended to decrease muscle mass. Muscle mass was only significantly increased with ME. All other interventions including exercise effectively preserved muscle mass. A BMI and/or WC decrease was achieved with all interventions except AT/RT alone or RT plus HP. Overall, the most effective strategy for nearly all outcomes was combining energy restriction with RT or ME and HP. Healthcare professionals involved in the management of persons with obesity need to be aware that an energy-restricted diet alone may contribute to sarcopenic obesity in persons near retirement age. This network meta-analysis is registered at https://www.crd.york.ac.uk/prospero/as CRD42021276465.

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.

Association of nut consumption with CVD risk factors in young to middle-aged adults: The Coronary Artery Risk Development in Young Adults (CARDIA) study

BACKGROUND AND AIMS

Few studies have examined long-term associations of walnut, other nut, and no nut consumption with cardiovascular disease (CVD) risk factors. Results from prospective studies with long-term follow-up can provide further evidence for dietary guideline messaging to consume nuts. Therefore, we examined the associations of walnut, other nut, and no nut consumption with diet quality and CVD risk factors over 30 years of follow-up.

METHODS AND RESULTS

Data were analyzed from 3092 young adults enrolled in the Coronary Artery Risk Development in Young Adults (CARDIA) study. Dietary intake, including walnuts and other nuts, was assessed 3 times over 20 years. CVD risk factors were measured at multiple exams. General linear regression evaluated the associations of walnut, other nut, and no nut consumption with CVD risk factors over 30 years (Y30) of follow-up. The 20-year cumulative mean intake of walnuts (0.74 oz/d), other nuts (1.6 oz/d), or no nut consumption was differentially associated with HEI-2015 and CVD risk factors by Y30. Generally, walnut consumers had significantly higher HEI-2015, lower body mass index, waist circumference, blood pressure, and triglyceride concentration, and gained less weight since baseline than other nut consumers (p ≤ 0.05 for all). Further, walnut consumers had lower fasting blood glucose than no nut consumers (p ≤ 0.05).

CONCLUSION

Study findings that walnut and other nut consumption was associated with better CVD risk factors and diet quality aligns with the 2020-2025 US. Dietary Guidelines for Americans recommendation to consume nuts, such as walnuts, within the context of a healthy diet.

Effects of nut consumption on blood lipid profile: A meta-analysis of randomized controlled trials

BACKGROUND & AIMS

Several randomized controlled trials (RCTs) have assessed the effects of nut consumption on blood lipid profile. The aim of this study was to conduct a meta-analysis to quantitatively estimate the effects of nut consumption on blood lipid profile.

METHODS AND RESULTS

The PubMed, EMBASE, Cochrane Library, and Google Scholar databases were systematically searched to identify RCTs examining the effects of nut intake on blood total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TGs) from inception until March 2021. A random-effects model was used to pool standardized mean differences (SMDs) and 95% confidence intervals (CIs). Potential publication bias was assessed using Begg's test and Egger's test. Sensitivity analysis was performed to assess the impact of each individual study on the pooled results. The meta-analysis showed that nut consumption had no significant effect on the blood lipid profile. However, there was a significant reduction in TC (SMD: -2.89, 95% CI: -4.80, -0.98, I² = 97.4) for pistachio consumption, and cashew consumption significantly increased HDL-C (SMD: 0.24, 95% CI: 0.04, 0.43, I² = 0.0) compared with that in controls. There was no significant publication bias in the meta-analysis. The sensitivity analysis showed that removing one study at a time did not change the significance of the results.

CONCLUSION

There was no overall effect of nut consumption on lipid profile, and the results may vary depending on nut type. We found that pistachio consumption may reduce TC levels, while cashew consumption increases HDL-C.

REGISTRY NUMBER

PROSPERO CRD42021249147.

The low-carbohydrate-diet score is associated with resting metabolic rate: an epidemiologic study among Iranian adults

Purpose

Low-carbohydrate diet (LCD) has been used for weight loss and preventing obesity, but the association of adherence to LCD and resting metabolic rate (RMR) has not been investigated. This study aimed to investigate the association between the low-carbohydrate-diet score (LCDS) and RMR among Iranian adults.

Methods

This cross-sectional study was conducted on 270 Iranian adults 18-70 y of age. To assess dietary intakes, participants completed a validated food frequency questionnaire. The LCDS was calculated based on carbohydrate, protein and fat intake, expressed as a percentage of energy. The higher score indicates the lower carbohydrate and the higher protein and fat intake. RMR was measured by indirect calorimetry after an overnight fast.

Results

Multivariate-adjusted means showed that RMR significantly increased across tertiles (p = 0.041). However, there were no significant differences in the mean of fat mass (FM) and fat-free mass (FFM) across tertiles of LCDS (p = 0.986 and p = 0.621, respectively). Also LCDS and RMR (r = 0.14, p = 0.021) were found to be correlated, but LCDS and FFM (r = 0.06, p = 0.323), FM (r = -0.05, p = 0.412), had no statistically significant correlation. RMR had a significant positive association with LCDs in the crude model (β = 18.81, 95% CI: 2.55, 35.07, P = 0.024). Moreover, after controlling for covariates this association changed to non-significant (β = -0.14, 95% CI: -7.05, 19.25, P = 0.03).

Conclusion

Adherence to diets lower in carbohydrates and higher in fat and protein were associated with higher RMR. Further studies with a larger sample size are needed to confirm these findings.

The effect of almond intake on glycemic control: A systematic review and dose-response meta-analysis of randomized controlled trials

Number trials have evaluated the effect of almond intake on glycemic control in adults; however, the results remain equivocal. Therefore, the present meta-analysis aims to examine the effectiveness of almond intake on glycemic parameters. Online databases including PubMed, Scopus, ISI web of science, Embase, and Cochrane Library were searched up to August 2021 for trials that examined the effect of almond intake on glycemic control parameters including fasting blood sugar (FBS), insulin, HOMA-IR, and HbA1C. Treatment effects were expressed as mean difference (MD) and the standard deviation (SD) of outcomes. To estimate the overall effect of almond intake, we used the random-effects model. In total, 24 studies with 31 arms were included in our analysis. The meta-analysis revealed that almond intake did not significantly change the concentrations of FBS, HbA1c, insulin levels, and HOMA-IR. In conclusion, there is currently no convincing evidence that almonds have a clear beneficial effect on glycemic control. Future studies are needed before any confirmed conclusion could be drowned.

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

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

Snacking on Almonds Lowers Glycaemia and Energy Intake Compared to a Popular High-Carbohydrate Snack Food: An Acute Randomised Crossover Study

Consuming nuts may have advantages over other snack foods for health and body-weight regulation. Suggested mechanisms include increased satiety and lower glycaemia. We used an acute randomised crossover trial to assess glycaemic and appetite responses to consuming two isocaloric snacks (providing 10% of participants’ total energy requirements or 1030 kJ (equivalent to 42.5 g almonds), whichever provided greater energy): raw almonds and sweet biscuits among 100 participants with available data (25 males and 75 females) following 106 being randomised. Two hours after consuming a standardised breakfast, participants consumed the snack food. Finger-prick blood samples measuring blood glucose and subjective appetite ratings using visual analogue scales were taken at baseline and at 15 or 30 min intervals after consumption. Two hours after snack consumption, an ad libitum lunch was offered to participants and consumption was recorded. Participants also recorded food intake for the remainder of the day. The mean area under the blood glucose response curve was statistically and practically significantly lower for almonds than biscuits (mean (95% CI) difference: 53 mmol/L.min (45, 61), p < 0.001). Only the composite appetite score at 90 min was higher in the almond treatment compared to the biscuit treatment (45.7 mm vs. 42.4 mm, p = 0.035 without adjustment for multiple comparisons). There was no evidence of differences between the snacks for all other appetite ratings or for energy intake at the ad libitum lunch. However, mean energy intakes following snack consumption were significantly lower, both statistically and in practical terms, for the almond treatment compared to the biscuit (mean (95% CI) diff: 638 kJ (44, 1233), p = 0.035). Replacing popular snacks with almonds may have advantages in terms of glycaemia and energy balance.

The Effects of Almonds on Gut Microbiota, Glycometabolism, and Inflammatory Markers in Patients with Type 2 Diabetes: A Systematic Review and Meta-Analysis of Randomised Controlled Trials

The use of nutritional interventions for managing diabetes is one of the effective strategies aimed at reducing the global prevalence of the condition, which is on the rise. Almonds are the most consumed tree nut and they are known to be rich sources of protein, monounsaturated fatty acids, essential minerals, and dietary fibre. Therefore, the aim of this review was to evaluate the effects of almonds on gut microbiota, glycometabolism, and inflammatory parameters in patients with type 2 diabetes.

METHODS

This systematic review and meta-analysis was carried out according to the preferred reporting items for systematic review and meta-analysis (PRISMA). EBSCOhost, which encompasses the Health Sciences Research Databases; Google Scholar; EMBASE; and the reference lists of articles were searched based on population, intervention, control, outcome, and study (PICOS) framework. Searches were carried out from database inception until 1 August 2021 based on medical subject headings (MesH) and synonyms. The meta-analysis was carried out with the Review Manager (RevMan) 5.3 software.

RESULTS

Nine randomised studies were included in the systematic review and eight were used for the meta-analysis. The results would suggest that almond-based diets have significant effects in promoting the growth of short-chain fatty acid (SCFA)-producing gut microbiota. Furthermore, the meta-analysis showed that almond-based diets were effective in significantly lowering (p < 0.05) glycated haemoglobin (HbA1c) levels and body mass index (BMI) in patients with type 2 diabetes. However, it was also found that the effects of almonds were not significant (p > 0.05) in relation to fasting blood glucose, 2 h postprandial blood glucose, inflammatory markers (C-reactive protein and Tumour necrosis factor α, TNF-α), glucagon-like peptide-1 (GLP-1), homeostatic model assessment of insulin resistance (HOMA-IR), and fasting insulin. The biological mechanisms responsible for the outcomes observed in this review in relation to reduction in HbA1c and BMI may be based on the nutrient composition of almonds and the biological effects, including the high fibre content and the low glycaemic index profile.

CONCLUSION

The findings of this systematic review and meta-analysis have shown that almond-based diets may be effective in promoting short-chain fatty acid-producing bacteria and lowering glycated haemoglobin and body mass index in patients with type 2 diabetes compared with control. However, the effects of almonds were not significant (p > 0.05) with respect to fasting blood glucose, 2 h postprandial blood glucose, inflammatory markers (C-reactive protein and TNF-α), GLP-1, HOMA-IR, and fasting insulin.

Effects of a Brazilian cardioprotective diet and nuts on cardiometabolic parameters after myocardial infarction: study protocol for a randomized controlled clinical trial

Background

Nut consumption has been related to improvements on cardiometabolic parameters and reduction in the severity of atherosclerosis mainly in primary cardiovascular prevention. The objective of this trial is to evaluate the effects of the Brazilian Cardioprotective Diet (DIetaCArdioprotetoraBrasileira, DICA Br) based on consumption of inexpensive locally accessible foods supplemented or not with mixed nuts on cardiometabolic features in patients with previous myocardial infarction (MI).

Methods

DICA-NUTS study is a national, multicenter, randomized 16-week follow-up clinical trial. Patients over 40 years old with diagnosis of previous MI in the last 2 to 6 months will be recruited (n = 388). A standardized questionnaire will be applied to data collection and blood samples will be obtained. Patients will be allocated in two groups: Group 1: DICA Br supplemented with 30 g/day of mixed nuts (10 g of peanuts, 10 g of cashew, 10 g of Brazil nuts); and Group 2: only DICA Br. The primary outcome will consist of LDL cholesterol means (in mg/dL) after 16 weeks of intervention. Secondary outcomes will consist of other markers of lipid profile, glycemic profile, and anthropometric data.

Discussion

It is expected that DICA Br supplemented with mixed nuts have superior beneficial effects on cardiometabolic parameters in patients after a MI, when compared to DICA Br.

Trial registration

ClinicalTrials.gov Identifier NCT03728127. First register: November 1, 2018; Last update: June 16, 2021. World Health Organization Universal Trial Number (WHO-UTN): U1111-1259-8105.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05494-0.

The Relationship of Tree Nuts and Peanuts with Adiposity Parameters: A Systematic Review and Network Meta-Analysis

The network meta-analysis and systematic review conducted aim to comparatively assess the effects of tree nuts and peanuts on body weight (BW), body mass index (BMI), waist circumference (WC), and body fat percentage (BF%). A systematic search up to 31 December 2020 was performed. A random-effects network meta-analysis was conducted following the PRISMA-NMA statement. A total of 105 randomized controlled trials (RCTs) with measures of BW (n = 6768 participants), BMI (n = 2918), WC (n = 5045), and BF% (n = 1226) were included. The transitivity assumption was met based on baseline characteristics. In the comparisons of nut consumption versus a control diet, there was no significant increase observed in any of the adiposity-related measures examined except for hazelnut-enriched diets, which raised WC. Moreover, almond-enriched diets significantly reduced WC compared to the control diet and to the pistachio-, mixed nuts-, and hazelnut-enriched diets. In subgroup analyses with only RCTs, designed to assess whether nut consumption affected weight loss, almonds were associated with reduced BMI and walnuts with reduced %BF. The evidence supports that: (1) tree nut and peanut consumption do not influence adiposity, and (2) compared to a control diet, the consumption of almond-enriched diets was associated with a reduced waist circumference.

Impact of Christian Orthodox Church dietary recommendations in Metabolic Syndrome risk factors: a scoping review

Fasting has been a practice among followers of different religions for many years. Christian Orthodox Church (COC) fasting is a periodic vegetarian-type diet while seafood and snails are allowed on most fasting days. The present scoping review aimed to present available data regarding the benefits of COC fasting on metabolic syndrome (MetS) risk factors. Databases were searched for available studies. Twenty publications, with a total of 1226 fasting participants, provided data on the effects on different variables of the MetS, including blood pressure, blood lipids and anthropometric measurements. Fasters' diet is characterized by low saturated and trans fat intake, high complex carbohydrate and fiber consumption, due to foods allowed to consume. COC fasting has no deficiency in essential amino acids intake since seafood and snails allowed on fasting days. Fasters have healthier blood lipid profiles during and after COC fasting periods, total cholesterol, low-density lipoprotein cholesterol, systolic blood pressure, body weight and body mass index are reduced after a fasting period. Due to restricted or forbidden intake of specific foods during the COC fasting periods, one might expect that fasters may have reduced intake of macro- and micro-nutrients, but as showed in the available literature there are no deficiencies. Future research on COC fasting is needed in areas not investigated at all, like MetS, before reaching definite conclusions.

A Comprehensive Review of Almond Clinical Trials on Weight Measures, Metabolic Health Biomarkers and Outcomes, and the Gut Microbiota

This comprehensive narrative review of 64 randomized controlled trials (RCTs) and 14 systematic reviews and/or meta-analyses provides an in-depth analysis of the effect of almonds on weight measures, metabolic health biomarkers and outcomes, and the colonic microbiota, with extensive use of figures and tables. Almonds are a higher energy-dense (ED) food that acts like a lower ED food when consumed. Recent systematic reviews and meta-analyses of nut RCTs showed that almonds were the only nut that had a small but significant decrease in both mean body mass and fat mass, compared to control diets. The biological mechanisms for almond weight control include enhanced displacement of other foods, decreased macronutrient bioavailability for a lower net metabolizable energy (ME), upregulation of acute signals for reduced hunger, and elevated satiety and increased resting energy expenditure. The intake of 42.5 g/day of almonds significantly lowered low-density lipoprotein cholesterol (LDL-C), 10-year Framingham estimated coronary heart disease (CHD) risk and associated cardiovascular disease (CVD) medical expenditures. Diastolic blood pressure (BP) was modestly but significantly lowered when almonds were consumed at >42.5 g/day or for >6 weeks. Recent RCTs suggest possible emerging health benefits for almonds such as enhanced cognitive performance, improved heart rate variability under mental stress, and reduced rate of facial skin aging from exposure to ultraviolet (UV) B radiation. Eight RCTs show that almonds can support colonic microbiota health by promoting microflora richness and diversity, increasing the ratio of symbiotic to pathogenic microflora, and concentrations of health-promoting colonic bioactives. Almonds are a premier healthy snack for precision nutrition diet plans.

Health Benefits Related to Tree Nut Consumption and Their Bioactive Compounds

Long-term studies with regular tree nut consumption have indicated positive outcomes for multiple health benefits. Here, we review the beneficial effects of tree nuts, highlighting the impact on glucose modulation, body weight management, cardiovascular risk, inflammation, oxidative stress, cognitive performance, and gut microbiota. Nuts are important sources of nutrients and phytochemicals, which, together with a healthy lipid profile, could help prevent certain chronic diseases, protect against oxidative stress and inflammation, and improve cognitive performance, thus reducing the impact of aging and neurodegeneration.

Effect of tree nuts on glycemic outcomes in adults with type 2 diabetes mellitus: a systematic review

OBJECTIVE

The objective of this review was to synthesize the best available research evidence regarding the effectiveness of tree nuts on glycemic outcomes in adults with type 2 diabetes mellitus.

INTRODUCTION

There has been an increase in the use of complementary therapy, particularly botanical products, for management of type 2 diabetes mellitus. It has been reported that increasing mono- and polyunsaturated fatty acids in diet effectively lowers the risk of development of type 2 diabetes mellitus. Hence, it was hypothesized that consumption of nuts, which are high in polyunsaturated fatty acids and mono-unsaturated fatty acids, may aid in preventing diabetes and reducing levels of blood glucose by reducing glycemic load by displacing dietary carbohydrates present in diet.

INCLUSION CRITERIA

This systematic review included randomized controlled trials that compared the consumption of any type and form of tree nut with a placebo or any other intervention in adults with type 2 diabetes mellitus. Trials were included if they measured fasting blood glucose, postprandial blood glucose, and/or glycated hemoglobin. Trials that assessed triglyceride levels and weight postintervention were also considered for inclusion. Trials were restricted to the English language.

METHODS

A three step search of PubMed, CINAHL, Embase, Trip database, and Cochrane Central Register of Controlled Trials (CENTRAL) was done in July 2019. To find unpublished studies, ClinicalTrials.gov and Google Scholar were searched. Studies from the search were reviewed against the inclusion criteria by two reviewers. The JBI critical appraisal checklist for randomized controlled trials was used to assess the potential studies for methodological quality. A meta-analysis and subgroup analysis was conducted among trials with the same type of intervention and outcome measures. Results are presented in a narrative format where statistical pooling was not possible.

RESULTS

Fifteen trials were included with a total sample size of 667. Consumption of pistachios demonstrated a significant reduction in triglyceride levels (mmol/L) at three month or earlier follow-up (mean difference [MD] -0.28; confidence interval -0.33, -0.23; P <0.00001). The meta-analysis including all tree nuts combined showed reduction in both fasting blood glucose and glycated hemoglobin (MD -0.26 mmol/L and -0.11% respectively) at three month or earlier follow-up. The subgroup analysis demonstrated MD of -0.45, -0.16, and -0.90 mmol/L in fasting blood glucose following ingestion of walnuts, almonds, and hazelnuts, respectively, and -0.17% in glycated hemoglobin following ingestion of walnuts at three month or earlier follow-up. Although not clinically significant, these figures give an indication that further research with larger sample sizes and longer follow-up may show encouraging results.

CONCLUSIONS

The authors found that pistachio consumption for three months or less significantly reduced triglyceride levels. Other tree nuts (walnuts, almonds, and hazelnuts) reduced fasting blood glucose and glycated hemoglobin levels by varying degrees. Further robust randomized controlled trials with power calculation-based sample size, comparing same type, dose, and method of nut intervention, will provide more evidence. For now, clinical decisions should be based on standard practice local guidelines.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO CRD42019133558.

Almond consumption decreases android fat mass percentage in adults with high android subcutaneous adiposity but does not change HbA1c in a randomised controlled trial

The purpose of this study was to determine if the mixed evidence of almond consumption on HbA1c stems from testing people with different body fat distributions (BFD) associated with different risks of glucose intolerance. A 6-month randomised controlled trial in 134 adults was conducted. Participants were randomly assigned to the almond (A) or control (C) group based on their BFD. Those in the almond group consumed 1·5 oz of almonds with their breakfast and as their afternoon snack daily. Those in the control group continued their habitual breakfast and afternoon snack routines. Body weight and composition were measured and blood samples were collected for determination of HbA1c, glycaemia and lipaemia at 0 and 6 months. Appetite ratings, energy intake and diet quality were collected at 0, 2, 4 and 6 months. Participants consuming almonds ingested 816 (sem 364) kJ/d more than participants in the control group (P = 0·03), but this did not result in any differences in body weight (A: –0·3 (sem 0·4), C: –0·4 (sem 0·4); P > 0·3). Participants in the almond, high android subcutaneous adipose tissue (SAT) group had a greater reduction in android fat mass percentage (A: –1·0 (sem 0·6), C: 1·1 (sem 0·6); P = 0·04), preserved android lean mass percentage (A: 0·9 (sem 0·6), C: –1 (sem 0·6); P = 0·04) and tended to decrease android visceral adipose tissue mass (A: –13 (sem 53) g, C: 127 (sem 53) g; P = 0·08) compared with those in the control, high SAT group. There were no differences in HbA1c between groups (A: 5·4 (sem 0·04), C: 5·5 (sem 0·04); P > 0·05). Thus, BFD may not explain the mixed evidence on almond consumption and HbA1c. Long-term almond consumption has limited ability to improve cardiometabolic health in those who are overweight and obese but otherwise healthy.

The effect of almond intake on anthropometric indices: a systematic review and meta-analysis

This systematic review and meta-analysis of randomized controlled trials (RCTs) was conducted to summarize the effect of almond intake on anthropometric indices in adult subjects. We searched PubMed, Scopus, ISI Web of Science, Cochrane Library, and Google Scholar databases until January 2020 to identify relevant RCTs. Data were reported as weighted mean differences (WMDs) and standard deviations (SDs) to show the magnitude of effects of almond on body weight (BW), body mass index (BMI), waist circumference (WC), fat mass (FM), and fat-free mass (FFM). Out of 2983 reports, 28 RCTs (37 arms) were eligible for including in our meta-analysis. The pooled results, obtained using a random-effects model, showed that almond intake significantly decreased BW (WMD: -0.38 kg, 95% CI: -0.65, -0.10, p = 0.007, I2 = 30.5%) and FM (WMD: -0.58 kg, 95% CI: -0.87, -0.28, p < 0.001, I2 = 4.9%). However, we found no significant effect of almond administration on BMI (WMD: -0.30 kg m-2, 95% CI: -0.67, 0.06, p = 0.101, I2 = 62.6%), WC (WMD: -0.60 cm, 95% CI: -1.28, 0.06, p = 0.078, I2 = 0.0%), and FFM (WMD: 0.23 kg, 95% CI: -0.04, 0.50, p = 0.097, I2 = 49.5%). Overall, the current meta-analysis demonstrated that resveratrol almond intake significantly reduced weight and FM, but did not affect BMI, WC, and FFM. Further studies are still required to confirm our results.

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.

Whole almond consumption is associated with better diet quality and cardiovascular disease risk factors in the UK adult population: National Diet and Nutrition Survey (NDNS) 2008-2017

PURPOSE

 This work aimed to estimate whole almond consumption in a nationally representative UK survey population and examine associations with diet quality and cardiovascular disease (CVD) risk.

METHODS

 Four-day food record data from the National Diet and Nutrition Survey (NDNS) 2008-2017 (n = 6802, age ≥ 19 year) were analyzed to investigate associations between whole almond consumption and diet quality, measured by the modified Mediterranean Diet Score (MDS) and modified Healthy Diet Score (HDS), and CVD risk markers, using survey-adjusted multivariable linear regression.

RESULTS

 Whole almond consumption was reported in 7.6% of the population. Median intake in whole almond consumers was 5.0 g/day (IQR 9.3). Consumers had higher diet quality scores relative to non-consumers; higher intakes of protein, total fat, monounsaturated, n-3 and n-6 polyunsaturated fats, fiber, folate, vitamin C, vitamin E, potassium, magnesium, phosphorus, and iron; and lower intakes of trans-fatty acids, total carbohydrate, sugar, and sodium. BMI and WC were lower in whole almond consumers compared to non-consumers: 25.5 kg/m2 (95% CI 24.9, 26.2) vs 26.3 kg/m2 (25.9, 26.7), and 88.0 cm (86.2, 89.8) vs 90.1 cm (89.1, 91.2), respectively. However, there were no dose-related fully adjusted significant associations between increasing almond intake (g per 1000 kcal energy intake) and lower CVD risk markers.

CONCLUSIONS

 Almond intake is low in the UK population, but consumption was associated with better dietary quality and lower CVD risk factors. Habitual consumption of whole almonds should be encouraged as part of a healthy diet.

Effect of a nut-enriched low-calorie diet on body weight and selected markers of inflammation in overweight and obese stable coronary artery disease patients: a randomized controlled study

BACKGROUND/OBJECTIVES

Weight loss through a low-calorie diet (LCD) could improve low-grade inflammation evident in the obese state. Few studies have evaluated the effect of the mixed nuts consumption in the context of a LCD on inflammatory biomarkers. This study compared the effects of a nut-enriched LCD (NELCD) with a nut-free LCD (NFLCD) on body weight and inflammatory markers in overweight or obese coronary artery disease (CAD) patients.

SUBJECTS/METHOD

In this randomized controlled parallel trial, patients with stable CAD of both genders were randomly allocated to 8-week NELCD or NFLCD. Body weight, plasma C-reactive protein (CRP), interleukin-6 (IL-6), interleukin 10 (IL-10), intercellular adhesion molecule-1 (ICAM-1), and monocyte chemoattractant protein (MCP-1) were assessed at baseline and 8 weeks.

RESULTS

Overall, 67 patients (aged 58.8 ± 7.4 years; BMI 30.9 ± 3.9 kg/m²) completed the study. Participants in both groups lost weight to a comparable extent. Patients in the NELCD group showed a decrease in ICAM-1 (p = 0.04) and IL-6 (p = 0.02) concentrations compared to NFLCD group. No significant difference in concentrations of MCP-1, IL-10, or CRP was observed between diet groups.

CONCLUSIONS

Nuts are healthy energy-dense foods that if included in controlled amounts in a weight management program can still result in weight reduction and may improve some plasma concentration of inflammatory factors, such as ICAM-1 and IL-6.

Nuts and Non-Alcoholic Fatty Liver Disease: Are Nuts Safe for Patients with Fatty Liver Disease?

Diet and lifestyle interventions are the recommended treatment for patients with non-alcoholic fatty liver disease (NAFLD), with the aim of achieving a 7-10% weight loss. Several dietary patterns have been suggested for this purpose, however, to date, the best one is represented by the Mediterranean diet (MD) as it is rich in macro- and micro- nutrients known for their effectiveness in health-promotion and cardio-vascular disease prevention. Moreover, MD is characterized by the inclusion of nuts. These foods have shown potential benefits in health-promotion as they are rich in fibers, which have lipid-lowering effects, rich in mono- and poly-unsaturated fatty acids, which help reduce insulin-resistance and serum cholesterol, and contain anti-oxidants which reduce oxidative stress and inflammation. Additionally, nuts are associated with a better control, or reduction, of Body Mass Index (BMI). All these effects are useful targets to achieve in NAFLD, so that nuts have been proposed as a suitable dietary treatment supplement for weight and metabolic control in these patients. In recent years, health authorities raised an alert on nuts consumption as these may be at high risk of aflatoxin (AF) contamination, for which controls and legislations are different among countries. AF is a well-known cancerogenic agent and a recognized risk factor for hepatocellular carcinoma. Patients with NAFLD have an overall, inherent sevenfold increased risk of developing hepatocellular carcinoma as compared with the general population. In this context, one could argue that recommending the inclusion of nuts in the diet of NAFLD patients has to be balanced with the risk of potential chronic exposure to AF, and every effort should be pursued to assure the safety of these nutrients. In this review, we aim to summarize the benefits of nuts consumption, the evidence for AF contamination of nuts and the consequent potential risks in patients with NAFLD.

Intake of Nuts or Nut Products Does Not Lead to Weight Gain, Independent of Dietary Substitution Instructions: A Systematic Review and Meta-Analysis of Randomized Trials

Several clinical interventions report that consuming nuts will not cause weight gain. However, it is unclear if the type of instructions provided for how to incorporate nuts into the diet impacts weight outcomes. We performed a systematic review and meta-analysis of published nut-feeding trials with and without dietary substitution instructions to determine if there are changes in body weight (BW) or composition. PubMed and Web of Science were searched through 31 December 2019 for clinical trials involving the daily consumption of nuts or nut-based snacks/meals by adults (≥18 y) for >3 wk that reported BW, BMI, waist circumference (WC), or total body fat percentage (BF%). Each study was categorized by whether or not it contained dietary substitution instructions. Within these 2 categories, an aggregated mean effect size and 95% CI was produced using a fixed-effects model. Quality of studies was assessed through the Cochrane risk-of-bias tool. Fifty-five studies were included in the meta-analysis. In studies without dietary substitution instructions, there was no change in BW [standardized mean difference (SMD): 0.01 kg; 95% CI: -0.07, 0.08; I2 = 0%] or BF% (SMD: -0.05%; 95% CI: -0.19, 0.09; I2 = 0%). In studies with dietary substitution instructions, there was no change in BW (SMD: -0.01 kg; 95% CI: -0.11, 0.09; I2 = 0%); however, there was a significant decrease in BF% (SMD: -0.32%; 95% CI: -0.61%, -0.03%; I2 = 35.4%; P < 0.05). There was no change in BMI or WC for either category of studies. Nut-enriched diet interventions did not result in changes in BW, BMI, or WC in studies either with or without substitution instructions. Slight decreases in BF% may occur if substitution instructions are used, but more research is needed. Limitations included varying methodologies between included studies and the frequency of unreported outcome variables in excluded studies.

The effectiveness of pistachio on glycemic control and insulin sensitivity in patients with type 2 diabetes, prediabetes and metabolic syndrome: A systematic review and meta-analysis

BACKGROUND AND AIMS

Pistachio nuts have been considered to improve dysglycemia. However, there are controversial results. This systematic review and meta-analysis carried out to evaluate the effects of pistachio nuts on glycemic control and insulin sensitivity in patients with type 2 diabetes mellitus (T2DM), prediabetes, and metabolic syndrome.

METHODS

Medline/PubMed, ProQuest, Web of Knowledge, Scopus, Cochrane library, and ScienceDirect were systematically searched to find randomized controlled trials (RCTs). Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) checklist was used to conduct the study.

RESULTS

Six RCTs were included in the review. Treatment with pistachio nuts exerted a significant reduction in fasting blood glucose (FBG) level (OR = 1.7, 95% CI; 1.2-2.4, P = 0.002, I² = 0.0%, P = 0.731) and homeostasis model assessment of insulin resistance (HOMA-IR) index (OR = 1.5, 95% CI; 1.0-2.4, P = 0.043, I² = 0.0%, P = 0.617), but no significant improvement was observed in regard to hemoglobin A1c (HbA1c) level (OR = 1.4, 95% CI; 0.9-2.1 P = 0.089, I² = 0.0%, P = 0.957) and fasting plasma insulin (FPI) level (OR = 1.3, 95% CI; 0.9-1.9, P = 0.133, I² = 0.0%, P = 0.776).

CONCLUSIONS

Pistachio nuts might cause a significant reduction in FBG and HOMA-IR, although HbA1c and FPI might not significantly improve in patients suffering from or at risk of T2DM.

Study protocol for a 9-month randomised controlled trial assessing the effects of almonds versus carbohydrate-rich snack foods on weight loss and weight maintenance

INTRODUCTION

Epidemiological studies indicate an inverse association between nut consumption and body mass index (BMI). However, clinical trials evaluating the effects of nut consumption compared with a nut-free diet on adiposity have reported mixed findings with some studies reporting greater weight loss and others reporting no weight change. This paper describes the rationale and detailed protocol for a randomised controlled trial assessing whether the inclusion of almonds or carbohydrate-rich snacks in an otherwise nut-free energy-restricted diet will promote weight loss during 3 months of energy restriction and limit weight regain during 6 months of weight maintenance.

METHODS AND ANALYSIS

One hundred and thirty-four adults aged 25-65 years with a BMI of 27.5-34.9 kg/m² will be recruited and randomly allocated to either the almond-enriched diet (AED) (15% energy from almonds) or a nut-free control diet (NFD) (15% energy from carbohydrate-rich snack foods). Study snack foods will be provided. Weight loss will be achieved through a 30% energy restriction over 3 months, and weight maintenance will be encouraged for 6 months by increasing overall energy intake by ~120-180 kcal/day (~500-750kJ/day) as required. Food will be self-selected, based on recommendations from the study dietitian. Body composition, resting energy expenditure, total daily energy expenditure (via doubly labelled water), physical activity, appetite regulation, cardiometabolic health, gut microbiome, liver health, inflammatory factors, eating behaviours, mood and personality, functional mobility and pain, quality of life and sleep patterns will be measured throughout the 9-month trial. The effects of intervention on the outcome measures over time will be analysed using random effects mixed models, with treatment (AED or NFD) and time (baseline, 3 months and 9 months) being the between and within factors, respectively in the analysis.

ETHICS AND DISSEMINATION

Ethics approval was obtained from the University of South Australia Human Research Ethics Committee (201436). Results from this trial will be disseminated through publication in peer-reviewed journals, national and international presentations.

TRIAL REGISTRATION NUMBER

Australian New Zealand Clinical Trials Registry (ACTRN12618001861246).

The effect of almond intake on blood pressure: A systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

The present systematic review and meta-analysis aimed determine the efficacy of almond intake on blood pressure (BP).

METHODS

PubMed, Scopus, ISI Web of Science, Cochrane library and Google Scholar were comprehensively searched to infinity until December 2019. Randomized clinical trials (RCTs) reporting effects of almond intake on aortic and brachial BP were included. Weighted mean differences (WMDs) were pooled using a random-effects model. Standard methods were used for assessment of heterogeneity, sensitivity analysis, and publication bias.

RESULTS

A total of 16 RCTs (1128 participants) were included in the meta-analysis. Pooled analysis suggested that almond intake can reduced diastolic BP (DBP) (WMD = -1.30 mmHg; 95 % CI: -2.31,-0.30, p = 0.01, I² = 0.0 %). However, there was not any impact of almond intake on systolic BP (SBP) (WMD = -0.83 mmHg; 95 % CI: -2.55, 0.89, p = 0.34, I² = 58.9 %). Subgroup analysis revealed a significant reduction in SBP levels in subjects with lower SBP and lower dose of almonds.

CONCLUSION

We found that almonds might have a considerable favorite effect in BP and especially in DBP, and it could be encouraged as part of a healthy diet; however due to the high calorie content, the intake should be part of healthy diet.

Effect of Cashew Nut on Lipid Profile: A Systematic Review and Meta-Analysis

INTRODUCTION

Nuts are one of the dietary components which appear to have beneficial effects on cardiovascular disease biomarkers. Studies demonstrate beneficial effects of cash-ews on serum lipids concentration, but results in the literature remain inconclusive. We conducted a review to examine the effects of cashew nut supplementation on serum lipid profile.

METHODS

Two reviewers independently searched PubMed, Web of Science, Cochrane Library, Scopus, and EMBASE electronic databases from inception until June 2019 without language limitation. Random- and fixed-effects models were used to calculate 95% confidence intervals (CI) for studies.

RESULTS

Six randomized clinical trials comprising 531 participants were included in this systematic review. Three studies were included in the meta-analysis model. There were no significant changes for total cholesterol (TC) (standardized mean difference [SMD]: -0.02, 95% CI: -0.32, 0.28), triglycerides (TG) (SMD: -0.01, 95% CI: -0.22, 0.20), high-density lipoprotein (HDL) cholesterol (SMD: 0.09, 95% CI: -0.16, 0.34), or low-density lipoprotein (LDL) cholesterol (SMD: -0.18, 95% CI: -0.75, 0.39).

CONCLUSION

The results of this analysis demonstrate that treatment with cashew nut supplementation alone did not significantly change serum levels of LDL, HDL, TC, or TG.

Diets with lower carbohydrate concentrations improve insulin sensitivity in women with polycystic ovary syndrome: A meta-analysis

OBJECTIVE

Women with polycystic ovary syndrome (PCOS) are associated with increased levels of insulin resistance (IR). Other than treatment with insulin-sensitizing drugs, specialized diets have also been implemented to reduce the patient's IR. However, the capacity of certain diets, concerning with the severity of the patient's IR, to improve insulin sensitivity has not fully been explored. Therefore, we conducted a meta-analysis to determine in PCOS subjects from low to severe IR, if hypocaloric diets improve insulin sensitivity.

STUDY DESIGN

PubMed, SCOPUS, EBSCO, and LILACS databases and retrieved studies' bibliographies were searched for prospective studies that investigated the association between diets and IR in PCOS women until October 2018. Diet was defined as a modification of the patients' nutrition intake according to caloric restriction, change in protein intake, or by using a specialized diet. IR measures (HOMA1-IR), pre- and post-intervention were extracted. Using Comprehensive Meta-Analysis software, depending on the level heterogeneity, determined by the ψ²-based Q-test and the I²-test, fixed-effects or random-effects models were used to calculate the pooled standard paired differences (SPD) and 95 %CI.

RESULTS

20 publications (25 studies) fulfilled the inclusion criteria. Due to the heterogeneity of the diets, the random-effects model was used. In 48 % of the studies, the diets led to a decrease of IR, where 44 % had no effect. In 2 studies, the diets increased IR. Overall, the diets decreased IR (SPD=-0.58; 95 %CI: -0.81 to -0.36). Subjects with severe IR (HOMA1-IR>4.2) had a marked improvement (SPD=-1.22; 95 %CI: -1.61 to -0.84). Moreover, diets low in carbohydrate (<50 %) was also determined to improve IR (SPD=-0.86; 95 %CI: -1.23 to -0.50).

CONCLUSIONS

Here, we demonstrate that diets are more likely to improve IR in PCOS women with severe IR. Therefore, it is crucial to determine a subject's IR status before considering any intervention containing a diet.

Tree nut snack consumption is associated with better diet quality and CVD risk in the UK adult population: National Diet and Nutrition Survey (NDNS) 2008–2014

Objectives:

To examine associations of tree nut snack (TNS) consumption with diet quality and cardiovascular disease (CVD) risk in UK adults from National Diet and Nutrition Survey (NDNS) 2008–2014.

Design:

Cross-sectional analysis using data from 4-d food diaries, blood samples and physical measurements for CVD risk markers. To estimate diet quality, modified Mediterranean Diet Score (MDS) and modified Healthy Diet Score (HDS) were applied. Associations of TNS consumption with diet quality and markers of CVD risk were investigated using survey-adjusted multivariable linear regression adjusted for sex, age, ethnicity, socio-economic and smoking status, region of residency and total energy and alcohol intake.

Setting:

UK free-living population.

Subjects:

4738 adults (≥19 years).

Results:

TNS consumers had higher modified MDS and HDS relative to non-consumers. TNS consumers also had lower BMI, WC, SBP and DBP and higher HDL compared to non-consumers, although a dose-related fully adjusted significant association between increasing nut intake (g per 4184 kJ/1000 kcal energy intake) and lower marker of CVD risk was only observed for SBP. TNS consumption was also associated with higher intake of total fat, mono-, n-3 and n-6 polyunsaturated fatty acids, fibre, vitamin A, thiamin, folate, vitamin C, vitamin E, potassium, magnesium, phosphorus, selenium and iron; and lower intake of saturated fatty acids, trans fatty acids, total carbohydrate, starch, free sugar, sodium and chloride.

Conclusions:

TNS consumers report better dietary quality and consumption was associated with lower CVD risk factors. Encouraging replacement of less healthy snacks with TNS should be encouraged as part of general dietary guidelines.

Does Nut Consumption Reduce Mortality and/or Risk of Cardiometabolic Disease? An Updated Review Based on Meta-Analyses

Aim We aimed to determine if nut consumption decreases mortality and/or the risk of cardiometabolic diseases based on updated meta-analyses of epidemiological and intervention studies. Methods. An updated electronic search was conducted in PubMed/MEDLINE, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and the Cochrane Library databases for original meta-analyses to investigate the effects of nut consumption on cardiometabolic disease in humans. Results. Seven new meta-analyses were included in this updated review. Findings similar to our previous review were observed, showing that nut consumption significantly decreased cardiovascular disease (CVD) mortality (−19% to −25%; n = 4), coronary heart disease (CHD) mortality (−24% to −30%; n = 3), stroke mortality (−17% to −18%; n = 3), CVD incidence (−15% to −19 %; n = 4), CHD [or coronary artery disease (CAD)] incidence (−17% to −34%; n = 8), and stroke incidence (−10% to −11%; n = 6) comparing high with low categories of nut consumption. Fasting glucose levels (0.08 to 0.15 mmol/L; n = 6), total cholesterol (TC; 0.021 to 0.30 mmol/L; n = 10), and low-density lipoprotein cholesterol (LDL-C; 0.017 to 0.26 mmol/L; n = 10) were significantly decreased with nut consumption compared with control diets. Body weight and blood pressure were not significantly affected by nut consumption. Conclusion. Nut consumption appears to exert a protective effect on cardiometabolic disease, possibly through improved concentrations of fasting glucose, total cholesterol, and LDL-C.

Almond Consumption and Risk Factors for Cardiovascular Disease: A Systematic Review and Meta-analysis of Randomized Controlled Trials

Evidence suggests that eating nuts may reduce the risk of cardiovascular disease (CVD). We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) evaluating almond consumption and risk factors for CVD. MEDLINE, Cochrane Central, Commonwealth Agricultural Bureau, and previous systematic reviews were searched from 1990 through June 2017 for RCTs of ≥3 wk duration that evaluated almond compared with no almond consumption in adults who were either healthy or at risk for CVD. The most appropriate stratum was selected with an almond dose closer to 42.5 g, with a control most closely matched for macronutrient composition, energy intake, and similar intervention duration. The outcomes included risk factors for CVD. Random-effects model meta-analyses and subgroup meta-analyses were performed. Fifteen eligible trials analyzed a total of 534 subjects. Almond intervention significantly decreased total cholesterol (summary net change: -10.69 mg/dL; 95% CI: -16.75, -4.63 mg/dL), LDL cholesterol (summary net change: -5.83 mg/dL; 95% CI: -9.91, -1.75 mg/dL); body weight (summary net change: -1.39 kg; 95% CI: -2.49, -0.30 kg), HDL cholesterol (summary net change: -1.26 mg/dL; 95% CI: -2.47, -0.05 mg/dL), and apolipoprotein B (apoB) (summary net change: -6.67 mg/dL; 95% CI: -12.63, -0.72 mg/dL). Triglycerides, systolic blood pressure, apolipoprotein A1, high-sensitivity C-reactive protein, and lipoprotein (a) showed no difference between almond and control in the main and subgroup analyses. Fasting blood glucose, diastolic blood pressure, and body mass index significantly decreased with almond consumption of >42.5 g compared with ≤42.5 g. Almond consumption may reduce the risk of CVD by improving blood lipids and by decreasing body weight and apoB. Substantial heterogeneity in eligible studies regarding almond interventions and dosages precludes firmer conclusions.

Acute effects of an isocaloric macronutrient-matched breakfast meal containing almonds on glycemic, hormonal, and appetite responses in men with type 2 diabetes: a randomized crossover study

This randomized crossover study assessed the acute effects of almonds on postprandial glycemic, hormonal, and appetite responses in a sample of 7 men with type 2 diabetes (T2D). Participants completed 2 experimental visits during which a control (white bread, butter, cheese) and a test (white bread, almonds) meal were ingested. Energy, available carbohydrate, total lipid, and protein content were the same in both meals. Blood samples were collected in fasting state as well as 15, 30, 60, 90, 120, and 240 min postprandially for quantifying blood glucose, as well as insulin and glucagon-like peptide-1 (GLP-1) serum concentrations. Subjective appetite sensations were assessed using visual analog scales at the same time-points. Within this sample of participants, the test meal was found to be associated with lower postprandial glycemia and insulinemia, higher GLP-1 serum concentrations, decreased hunger and desire to eat, and increased fullness. The test meal was also associated with an increased estimated glucose metabolic clearance rate, indicating higher postprandial insulin sensitivity. Overall, results suggest that almonds' macronutrient subtype profile could have a beneficial impact on postprandial glycemic, hormonal, and appetite responses in men with T2D. Studies with larger sample sizes are warranted to confirm these findings. Novelty A meal containing almonds (vs. isocaloric macronutrient-matched control) induced lower glycemic and insulinemic responses. A meal containing almonds (vs. isocaloric macronutrient-matched control) induced a greater elevation in postprandial GLP-1 serum concentrations. A meal containing almonds (vs. isocaloric macronutrient-matched control) induced more favourable postprandial appetite responses.

Mixed Nut Consumption May Improve Cardiovascular Disease Risk Factors in Overweight and Obese Adults

Emerging research indicates that nuts are a source of health-promoting compounds demonstrating cardioprotective benefits. However, most studies have assessed the effect of single nuts rather than a nut mixture. The objective of this study was, therefore, to examine the effect of mixed-nut consumption on cardiovascular disease (CVD) risk factors in overweight and obese adults. In a randomized, parallel-arm, controlled trial, 48 participants consumed isocaloric (250 kcal) amounts of pretzels or mixed-nuts. Body weight (BW) (p = 0.024), BMI (p = 0.043), and insulin levels (p = 0.032) were significantly lower in the nut group compared to the pretzel group. Mixed-nut consumption also significantly reduced glucose (p = 0.04) and insulin (p = 0.032) levels after 4 and 8 weeks compared to baseline, respectively. Lactate dehydrogenase of the nut group was significantly lower than the pretzel group (p = 0.002). No significant differences were detected between groups for triglycerides, LDL-C, and HDL-C. However, pretzel consumption increased triglycerides (p = 0.048) from 4 weeks to 8 weeks. Moreover, LDL-C increased (p = 0.038) while HDL-C transiently decreased (p = 0.044) from baseline to 4 weeks. No significant lipid changes were detected within the nut group. Our results suggest that supplementing the diet with mixed-nuts could improve CVD risk factors by improving BW and glucose regulation in comparison to a common carbohydrate-rich snack without promoting the negative effects on lipids detected with pretzels.

Inverse association of long-term nut consumption with weight gain and risk of overweight/obesity: a systematic review

Nuts contain a variety of nutrients and bioactive compounds that are capable of promoting metabolic health. However, due to their high energy density, concerns have been raised that nut consumption in the long term may contribute to weight gain. This systematic review summarizes the findings of prospective studies regarding the relationship between long-term nut consumption and obesity. Searches were conducted up through February 2018, using the PUBMED, EMBASE, and SCOPUS databases with the relevant MeSH terms and phrases. This systematic review included prospective cohort studies investigating the relationship between consumption of total nut and/or nut subtypes with changes in weight, body mass index (BMI), and waist circumference (WC), as well as the risk of overweight/obesity, with follow-up duration ≥1-year. Out of a total of 1580 papers that were initially examined, 6 met the inclusion criteria. Four out of the 6 studies showed an inverse association between nut consumption (typically at the dosages of ≥1 to 2 servings per week) and weight gain and risk of overweight/obesity. The remaining 2 studies evaluated the association between nut intake and changes in WC. From these 2 studies, only one study reported a significant inverse association. Overall, evidence from limited cohort studies demonstrated that long-term nut intake was associated with less weight gain and reduced risk of overweight/obesity. Whether such findings are generalizable to racially diverse ethnic groups, individuals of low socioeconomic status, and populations in developing countries should be addressed in future studies.

The Type of Dietary Fat in an Isocaloric Breakfast Meal Does Not Modify Postprandial Metabolism in Overweight/Obese Pregnant Women

Almonds provide a satiating, healthy source of fat and fiber. The postprandial metabolic and satiety response to 2 ounces of nuts or dairy was assessed in 18 overweight/obese women during late pregnancy. Serum glucose, triglycerides, insulin, c-peptide, leptin, ghrelin, and lipoprotein particles were measured prior to and during a 5-h postprandial period following the consumption of an isocaloric breakfast meal with equivalent amounts of fat from either nuts or dairy on two separate mornings. Satiety was assessed by visual analogue scale (VAS) questionnaires and ad libitum food intake at the end of the study. At 33 weeks gestation, the women had gained an average of 7.0 ± 4.4 kg during gestation. Body fat averaged 41.9 ± 5.5% and hemoglobin A1c levels were elevated, (7.2 ± 0.6%). Fasting glucose levels were normal, but hyperinsulinemia was evident. The two test meals did not affect the postprandial metabolic response, but glucose, triglyceride, and ghrelin concentrations changed with time during the postprandial period (p < 0.001, p = 0.0008, p = 0.006). Satiety measures did not differ between the two test meals. Consuming an isocaloric breakfast meal with equivalent amounts of fat from nuts or dairy did not alter postprandial levels of blood lipids, glucose, hormones, or measures of satiety in overweight/obese, pregnant women.

The effect of nuts on markers of glycemic control: a systematic review and meta-analysis of randomized controlled trials

Background

Observational evidence suggests higher nut consumption is associated with better glycemic control; however, it is unclear if this association is causal.

Objectives

We aimed to conduct a systematic review and meta-analysis of randomized controlled trials to examine the effect of tree nuts and peanuts on markers of glycemic control in adults.

Methods

A systematic review and meta-analysis of randomized controlled trials was conducted. A total of 1063 potentially eligible articles were screened in duplicate. From these articles, 40 were eligible for inclusion and data from these articles were extracted in duplicate. The weighted mean difference (WMD) between the nut intervention and control arms was determined for fasting glucose, fasting insulin, glycated hemoglobin (HbA1c), and homeostasis model assessment of insulin resistance (HOMA-IR) using the DerSimonian and Laird random-effects method. For outcomes where a limited number of studies were published, a qualitative synthesis was presented.

Results

A total of 40 randomized controlled trials including 2832 unique participants, with a median duration of 3 mo (range: 1-12 mo), were included. Overall consumption of tree nuts or peanuts had a favorable effect on HOMA-IR (WMD: -0.23; 95% CI: -0.40, -0.06; I2 = 51.7%) and fasting insulin (WMD: -0.40 μIU/mL; 95% CI: -0.73, -0.07 μIU/mL; I2 = 49.4%). There was no significant effect of nut consumption on fasting blood glucose (WMD: -0.52 mg/dL; 95% CI: -1.43, 0.38 mg/dL; I2 = 53.4%) or HbA1c (WMD: 0.02%; 95% CI: -0.01%, 0.04%; I2 = 51.0%).

Conclusions

Consumption of peanuts or tree nuts significantly decreased HOMA-IR and fasting insulin; there was no effect of nut consumption on HbA1c or fasting glucose. The results suggest that nut consumption may improve insulin sensitivity. In the future, well-designed clinical trials are required to elucidate the mechanisms that account for these observed effects.

Fatty acid bioaccessibility and structural breakdown fromin vitrodigestion of almond particles

In vitrogastric digestion of almond particles using a model with simulated peristaltic contractions resulted in particle size reduction and higher fatty acid bioaccessibility thanin vitrodigestion using a model that lacked peristaltic contractions.

Effects of Daily Consumption of Cashews on Oxidative Stress and Atherogenic Indices in Patients with Type 2 Diabetes: A Randomized, Controlled-Feeding Trial

BACKGROUND

Cashews, as the main source of monounsaturated (MUFAs) and polyunsaturated (PUFAs) fatty acids, are associated with reduced risk of cardiovascular diseases. Despite evidence for beneficial effects of nuts on lipid profile and glycemic control, to the authors' best knowledge, little is known about cashews.

METHODS

An eight-week, randomized, isocaloric, controlled-feeding study was conducted on 50 patients with type 2 diabetes mellitus (T2DM) randomly assigned to either the control or intervention group (10% of total calorie from cashews). Weight, fasting plasma glucose (FPG), serum insulin concentration and sensitivity, lipid profile ratio, high-sensitive C-reactive protein (hs-CRP), total antioxidant capacity (TAC), and paraoxonase-1 (PON-1) were measured at baseline and after eight weeks of intervention adjusted for age, gender, baseline values of FPG, insulin, HOMA-IR (homeostatic model assessment of insulin resistance), fiber, and both baseline and post-intervention vitamin C levels as covariates.

RESULTS

Weight, body mass index (BMI), and waist circumference (WC) were not significantly different in the groups after eight weeks of intervention, as well as between the two groups, compared with the baseline measures. At the end of the study, serum insulin and low-density lipoprotein-cholesterol-to-high-density lipoprotein-cholesterol (LDL-C/HDL-C) ratio significantly decreased in the cashews group compared with those of the controls (P = 0.01 and P = 0.04, respectively). Although, HOMA-IR decreased significantly in the cashews group (P = 0.03), changes were not significant compared with the baseline measures (P = 0.056). Despite more increase in PON-1 activity in the cashews group, the changes were not statistically significant.

CONCLUSIONS

Daily consumption of cashews reduced serum insulin and LDL-C/HDL-C ratio in patients with T2DM. However, further studies with larger sample sizes and more duration are needed to confirm the current study results.

Nuts and Cardio-Metabolic Disease: A Review of Meta-Analyses

OBJECTIVES

Accumulating epidemiological and intervention evidence suggest that nut consumption is associated with reduced incidence of some cardiometabolic diseases. However, to date no review of meta-analyses of epidemiological and intervention studies has evaluated the effects of nut consumption on cardiometabolic disease. Design/Results: Electronic searches for meta-analyses of epidemiological and intervention studies were undertaken in PubMed®/MEDLINE®. Meta-analyses of prospective studies show that nut consumption appears to be associated with reduced all-cause mortality by 19⁻20% (n = 6), cardiovascular disease (CVD) incidence (19%; n = 3) and mortality (25%; n = 3), coronary heart disease (CHD) incidence (20⁻34%; n = 2) and mortality (27⁻30%; n = 2) and stroke incidence (10⁻11%; n = 7) and mortality (18%; n = 2). No association between nut consumption and the risk of type 2 diabetes mellitus (T2DM) was observed in meta-analyses of prospective studies, whereas a decrease in fasting blood glucose ranging from 0.08 to 0.15 mmol/L was observed in 3 meta-analyses of intervention studies. In the interventions, nut consumption also had favorable effects on total cholesterol (0.021 to 0.28 mmol/L reduction from 8 meta-analyses of interventions) and low-density lipoprotein cholesterol (0.017 to 0.26 mmol/L reduction from 8 meta-analyses of interventions) and endothelial function (0.79 to 1.03% increase in flow-mediated dilation from 4 meta-analyses of interventions). Nut consumption did not significantly affect body weight. Nut consumption had no effect on inflammatory markers in intervention studies. The effect on blood pressure was inconsistent. A higher nut consumption was associated with a lower incidence of hypertension in prospective studies, while nut consumption did not improve blood pressure in intervention studies.

CONCLUSIONS

Nut consumption appeared to be associated with lower all-cause mortality and CVD and CHD mortality. There was no association between nut consumption and the incidence of T2DM although fasting blood glucose is decreased in intervention studies. In intervention studies nuts lower total cholesterol and low-density lipoprotein cholesterol (LDL-C).

Potential Prebiotic Properties of Nuts and Edible Seeds and Their Relationship to Obesity

Obesity is a global epidemic chronic condition and is progressing at a rapid rate. This review focuses on the potential prebiotic properties of nuts and edible seeds and the plausible mechanisms that their consumption may help the prevention and the management of overweight and obesity. The literature review was performed by searching papers about the topic in MEDLINE and SCOPUS databases. The healthy attributes of nuts and edible seeds, especially dietary fibers and polyphenols contents, indicate that their mechanism of weight gain prevention may occur through interaction with the gut microbiota, by means of prebiotic effects. Among the etiological factors associated with obesity, the gut microbiota seems to play a significant role. Dysbiosis causes an imbalance in energy homeostasis that contributes to obesity. Three mechanisms are proposed in this review to explain the potential role of nut and edible seed consumption on intestinal homeostasis and body weight control: maintenance of the enteric barrier integrity, improvement of anti-inflammatory status and enhancement of butyrate synthesis. Further high-quality clinical trials should explore the interaction between oilseed consumption, microbiota, and body adiposity control, particularly investigating the microbiota metabolites and their relation to the prevention and management of obesity.