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

Knowledge, practices and perceptions of energy labelling of nut products among Australian consumers and stakeholders: an online survey

BACKGROUND

Nut consumption in Australia is low, perhaps due to concerns with weight gain. However, nut consumption is not associated with increased weight, in part because of their lower metabolisable energy. Current energy labelling for nuts use Atwater factors, which over-represent the available energy from nuts. Therefore, this research aimed to examine stakeholders' knowledge, practices and perceptions of displaying true metabolisable energy on nutrition labels and its perceived impact on nut consumption.

METHODS

An anonymous and voluntary survey was conducted online. Eligible respondents lived in Australia, were aged 18 years or older and had either no formal nutrition education (consumer group) or had formal training and were working as a stakeholder (stakeholder group; working in nutrition/dietetics, public health, food industry, food regulation or nut growing). Convenience sampling and snowballing were used to recruit respondents primarily via online advertisement.

RESULTS

Three hundred and forty-eight respondents (63.2% female; 71.0% aged 18-39 years; 69.0% Bachelor's degree or higher) were included in the analyses. A larger proportion of stakeholders agreed that nut consumption assists with weight management (67.9%) compared with consumers (47.6%). Theoretical food packaging showing both Atwater and metabolisable energy in the nutrition information panel was favoured among consumers and stakeholders, though 62.3% of consumers reported that a lower metabolisable energy of nuts would not impact their consumption.

CONCLUSIONS

This study indicates a need to further investigate the impact of metabolisable energy labelling on nut intake. Further education about the relationship between nuts and body weight is required for consumers and stakeholders.

Association between the EAT-Lancet Diet, Incidence of Cardiovascular Events, and All-cause Mortality: Results from a Swiss Cohort

BACKGROUND

An unhealthy diet is a major contributor to several noncommunicable diseases, including cardiovascular diseases (CVD), the leading cause of death worldwide. Additionally, our food system has significant impacts on the environment. The EAT-Lancet Commission has recommended a healthy diet that preserves global environmental resources.

OBJECTIVE

This prospective study evaluated the associations between adherence to the EAT-Lancet diet and the incidence of cardiovascular events and all-cause mortality in a Swiss cohort.

METHODS

We analyzed data from the CoLaus|PsyCoLaus cohort study (n = 3,866). Dietary intake was assessed using a semiquantitative food frequency questionnaire. The EAT-Lancet adherence score was calculated based on the recommended intake and reference intervals of 12 food components, ranging from 0 to 39 points. Participants were categorized into low-, medium-, and high-adherence groups according to score tertiles. We used Cox Proportional Hazards regressions to assess the association between diet adherence, incident cardiovascular events and all-cause mortality.

RESULTS

During a mean follow-up of 7.9 years (SD, ±2.0), 294 individuals (7.6%) from our initial sample experienced a first cardiovascular event, and 264 (6.8%) died. Compared with the low-adherence group, the adjusted hazard ratios for all-cause mortality were 0.88 (95% CI: 0.66-1.17) and 0.70 (95% CI: 0.49-0.98) for the medium- and high-adherence groups, respectively (p for trend = 0.04). We observed no association between adherence groups and cardiovascular events.

CONCLUSIONS

In a Swiss cohort, high adherence to the EAT-Lancet diet was associated with a potential 30% lower risk of overall mortality. However, no association was found between the EAT-Lancet diet and cardiovascular events.

Effect of nut consumption on blood lipids: An updated systematic review and meta-analysis of randomized controlled trials

AIMS

Nuts are nutrient-dense foods touted for their health-promoting effects, especially regarding cardiovascular health, yet inconsistencies in the literature remain in relation to their effect on blood lipids. Hence, a systematic review and meta-analysis of randomized controlled trials (RCTs) was conducted to determine the effect of nut intake on blood lipids.

DATA SYNTHESIS

MEDLINE-PubMed and Cochrane databases were searched. 113 unique trials met eligibility criteria (n = 8060 adults with various health status) assessing the effect of a median daily dose of 45.5 g/d of nuts compared to a non-nut control on blood lipid outcomes met inclusion criteria. Overall, nut consumption resulted in moderate reductions in total cholesterol (mean difference, -0.14 mmol/L [95 % confidence interval, -0.18 to -0.10 mmol/L]) and LDL-C (-0.12 mmol/L [-0.14 to -0.09 mmol/L]), with small reductions in triglycerides (-0.05 mmol/L [-0.07 to -0.03 mmol/L]), TC:HDL-C (-0.11 [-0.16 to -0.06]), LDL-C:HDL-C (-0.19 [-0.24 to -0.12]), and apolipoprotein B (-0.04 g/L [-0.06 to -0.02 g/L]). There was no significant impact on HDL-cholesterol or other assessed measures. Certainty of evidence was high for apolipoprotein A, and generally moderate/low for all other outcomes. Sensitivity analysis did not change the evidence on the main outcomes. Significant effect modifications in subgroup analysis were shown for most of the lipid parameters assessed. None of these subgroup effects altered the evidence of heterogeneity for any primary outcome.

CONCLUSIONS

Current evidence provides a good indication that consuming nuts may advantageously affect blood lipids in adults with a mix of health status.

PROSPERO REGISTRATION

PROSPERO identifier, CRD42022358688.

Effects of mixed nuts as part of a Brazilian Cardioprotective diet on LDL-cholesterol in adult patients after myocardial infarction: a multicenter randomized controlled clinical trial

BACKGROUND

Nuts consumption is related to cardioprotective effects on primary cardiovascular prevention, but studies conducted in secondary prevention are small, scarce and controversial. The objective of this trial was to evaluate the effects of a regional and sustainable cardioprotective diet added or not with an affordable mixed nuts on cardiometabolic features in patients with previous myocardial infarction.

METHODS

DICA-NUTS study is a national, multi-center, and superiority-parallel randomized clinical trial. Males and females over 40 years old diagnosed with previous myocardial infarction in the last 2 to 6 months were included. Patients were allocated into two groups: the Brazilian Cardioprotective diet (DICA Br) supplemented with 30 g/day of mixed nuts (10 g of peanuts; 10 g of cashew; 10 g of Brazil nuts) (intervention group, n = 193); or only DICA Br prescription (control group, n = 195). The primary outcome was low-density lipoprotein cholesterol means (in mg/dL) after 16 weeks. Secondary outcomes were other lipid biomarkers, glycemic and anthropometric data and diet quality.

RESULTS

After adjustment for baseline values, participating study site, time since myocardial infarction and statin treatment regimen (high potency, moderate and low potency/no statins), no significant difference was found between the groups in low-density lipoprotein cholesterol concentrations (intervention-control difference: 3.48 mg/dL [-3.45 to 10.41], P = 0.32). Both groups improved their overall diet quality at the end of the study without differences between them after 16 weeks (intervention-control difference: 1.05 (-0.9 to 2.99); P = 0.29). Other lipids, glycemic profile and anthropometrics were also not different between study groups at the end of the study.

CONCLUSION

Adding 30 g/day of mixed nuts to the DICA Br for 16 weeks did not change lipid, glycemic and anthropometric features in the post-myocardial infarction setting.

TRIAL REGISTRATION

This study is registered on ClinicalTrials.gov website under number NCT03728127 and its World Health Organization Universal Trial Number (WHO-UTN) is U1111-1259-8105.

Plant and Animal Fat Intake and Overall and Cardiovascular Disease Mortality

Importance

The impact of dietary fat intake on long-term human health has attracted substantial research interest, and the health effects of diverse dietary fats depend on available food sources. Yet there is a paucity of data elucidating the links between dietary fats from specific food sources and health.

Objective

To study associations of dietary plant and animal fat intake with overall mortality and cardiovascular disease (CVD) mortality.

Design, Setting, and Participants

This large prospective cohort study took place in the US from 1995 to 2019. The analysis of men and women was conducted in the National Institutes of Health-AARP Diet and Health Study. Data were analyzed from February 2021 to May 2024.

Exposures

Specific food sources of dietary fats and other dietary information were collected at baseline, using a validated food frequency questionnaire.

Main Outcomes and Measures

Hazard ratios (HRs) and 24-year adjusted absolute risk differences (ARDs) were estimated using multivariable-adjusted Cox proportional hazards regression.

Results

The analysis included 407 531 men and women (231 881 [56.9%] male; the mean [SD] age of the cohort was 61.2 [5.4] years). During 8 107 711 person-years of follow-up, 185 111 deaths were ascertained, including 58 526 CVD deaths. After multivariable adjustment (including adjustment for the relevant food sources), a greater intake of plant fat (HRs, 0.91 and 0.86; adjusted ARDs, -1.10% and -0.73%; P for trend < .001), particularly fat from grains (HRs, 0.92 and 0.86; adjusted ARDs, -0.98% and -0.71%; P for trend < .001) and vegetable oils (HRs, 0.88 and 0.85; adjusted ARDs, -1.40% and -0.71%; P for trend < .001), was associated with a lower risk for overall and CVD mortality, respectively, comparing the highest to the lowest quintile. In contrast, a higher intake of total animal fat (HRs, 1.16 and 1.14; adjusted ARDs, 0.78% and 0.32%; P for trend < .001), dairy fat (HRs, 1.09 and 1.07; adjusted ARDs, 0.86% and 0.24%; P for trend < .001), or egg fat (HRs, 1.13 and 1.16; adjusted ARDs, 1.40% and 0.82%; P for trend < .001) was associated with an increased risk for mortality for overall and CVD mortality, respectively, comparing the highest to the lowest quintile. Replacement of 5% energy from animal fat with 5% energy from plant fat, particularly fat from grains or vegetable oils, was associated with a lower risk for mortality: 4% to 24% reduction in overall mortality, and 5% to 30% reduction in CVD mortality.

Conclusions and Relevance

The findings from this prospective cohort study demonstrated consistent but small inverse associations between a higher intake of plant fat, particularly fat from grains and vegetable oils, and a lower risk for both overall and CVD mortality. A diet with a high intake of animal-based fat, including fat from dairy foods and eggs, was also shown to be associated with an elevated risk for both overall and CVD mortality.

Association between nut consumption and mortality risk: a 20-year cohort study in Korea with a stratified analysis by health-related variables

BACKGROUND

Although nuts are a well-known healthy food group, the relationship between nut consumption and mortality remains unclear, particularly among Asians. This prospective cohort study examined the association between nut consumption and the risk of all-cause, cardiovascular disease (CVD), and cancer mortality in Korean adults.

METHODS

Data from two cohorts (the Ansan-Ansung and Health-Examinees) from the Korean Genome and Epidemiology Study were used. A total of 114,140 individuals aged 40-79 years were included in the data analyses. Nut consumption was assessed using a validated semi-quantitative food frequency questionnaire and categorized into four groups: non-consumers, less than 1 serving/week, 1-2 servings/week, and 2 or more servings/week (one serving was 15 g of nuts). Mortality outcomes were determined based on the 2001-2021 death records from Statistics Korea. Cox proportional hazard regression analysis was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for mortality across nut consumption categories. A stratified subgroup analysis by health-related variables was also performed.

RESULTS

During a mean follow-up of 12.3 years, 4,559 deaths were recorded. After adjusting for covariates, the HR for all-cause mortality was 0.877 (95% CI = 0.772-0.996, p for trend = 0.006) in individuals with a nut consumption of 2 or more servings/week compared with that in non-consumers. Multivariable HRs for CVD mortality were 0.800 (95% CI = 0.681-0.939) in individuals consuming less than 1 serving/week, 0.656 (95% CI = 0.469-0.918) in those consuming 1-2 servings/week, and 1.009 (95% CI = 0.756-1.347) in those consuming 2 or more servings/week compared with that in non-consumers (p for trend = 0.080). No association was observed between nut consumption and cancer mortality. Stratified analysis identified significant interactions in the association between nut consumption and all-cause mortality by age, body mass index, and physical activity.

CONCLUSIONS

Nut consumption was linearly associated with the reduced risk of all-cause mortality and showed a non-linear dose-response relationship with CVD mortality in Koreans, but had no association with cancer mortality. The effects of nut consumption, which have been inadequately investigated in this population, varied across different subgroups. These findings suggest that incorporating nuts into the diet should be encouraged for long-term health of Korean adults.

Association between Planetary Health Diet and Cardiovascular Disease: A Prospective Study from the UK Biobank

BACKGROUND

The Planetary Health Diet index (PHDI) prioritizes the well-being of both individuals and the planet but has yielded mixed results on cardiovascular disease (CVD). Our aim was to assess the association between the PHDI and risk of CVD.

METHODS

A cohort of 118,469 individuals aged 40-69 years from the UK Biobank, who were free of CVD at 2009-2012 and followed-up to 2021. The PHDI was calculated using at least two 24-h dietary assessments and included 14 food groups, with a possible range from 0 to130 points. CVD incidence was defined as primary myocardial infarction or stroke and obtained from clinical records and death registries.

RESULTS

During a 9.4-year follow-up, 5,257 incident cases of CVD were ascertained. When comparing the highest (89.9-128.5 points) versus the lowest quartile (21.1-71.1 points) of PHDI adherence, the multivariable-adjusted hazard ratio (95% confidence interval) was 0.86 (0.79, 0.94) for CVD, 0.88 (0.80, 0.97) for myocardial infarction, and 0.82 (0.70, 0.97) for stroke. The association was linear until a plateau effect was reached at 80 points of adherence to PHDI. Results remained robust when excluding participants with type 2 diabetes, including only those with three or more diet assessments, or excluding CVD cases in the first three years of follow-up. The food group components of the PHDI more strongly associated with reduced CVD risk were higher consumption of whole grains, whole fruits, fish and lower consumption of added sugars and fruit juices.

CONCLUSION

In this large cohort of middle-aged and older British adults, adherence to the PHDI was associated with lower risk of CVD. These results provide empirical evidence that this dietary pattern, thought to be environmentally sustainable, benefits cardiovascular health.

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.

Metabolisable energy from nuts and patterns of nut consumption in the Australian population: a secondary analysis of the 2011-12 National Nutrition and Physical Activity Survey

BACKGROUND

Nut intake is not associated with increased body weight, which may be explained by their metabolisable energy, among other factors. Therefore, total energy intake may be overestimated among nut consumers. This study aimed to describe the metabolisable energy from nuts and nut consumption patterns in the Australian population.

METHODS

A nut-specific database was expanded to include metabolisable energy of nuts (based on nut type and form) and applied to the 2011-12 National Nutrition and Physical Activity Survey (NNPAS). Participants were Australians aged 2 years and older from the 2011-12 NNPAS (n = 12,153, with n = 4,765 nut consumers). Mean metabolisable energy intake was compared with mean energy intake using Atwater factors in nut consumers. Additionally, nut consumption patterns were explored, including the proportion of nuts consumed at meals and snacks.

RESULTS

Among nut consumers, mean metabolisable energy from nuts based only on nut type was 241.2 (95% confidence interval [CI]: 232.0, 250.5) kJ/day and mean metabolisable energy considering both nut type and form was 260.7 (95% CI: 250.2, 271.2) kJ/day. Energy intake from nuts using Atwater factors was 317.6 (95% CI: 304.8, 330.3) kJ/day. Nuts were more likely to be consumed at snack occasions, with approximately 63% of nut intake occurring as a snack.

CONCLUSION

Application of metabolisable energy to the 2011-12 NNPAS has a significant impact on calculation of energy intake from nuts. Nut consumption patterns identified a majority of nut consumption occurring as snacks. These findings may inform strategies to support nut consumption in Australia.

The Cardioprotective Properties of Selected Nuts: Their Functional Ingredients and Molecular Mechanisms

Nuts have been known as a nutritious food since ancient times and can be considered part of our original diet: they are one of the few foods that have been eaten in the same form for thousands of years. They consist of various dry fruits and seeds, with the most common species being almonds (Prunus dulcis), hazelnuts (Corylus avellana), cashews (cashew nuts, Anacardium occidentale), pistachios (Pistacia vera), walnuts (Italian nuts, Juglans regia), peanuts (Arachia hypogaca), Brazil nuts (Bartholletia excels), pecans (Corya illinoinensis), macadamia nuts (Macademia ternifolia) and pine nuts. Both in vitro and in vivo studies have found nuts to possess a range of bioactive compounds with cardioprotective properties, and hence, their consumption may play a role in preventing and treating cardiovascular diseases (CVDs). The present work reviews the current state of knowledge regarding the functional ingredients of various nuts (almonds, Brazil nuts, cashew nuts, hazelnuts, macadamia nuts, peanuts, pecan nuts, pine nuts, pistachios, and walnuts) and the molecular mechanisms of their cardioprotective action. The data indicate that almonds, walnuts and pistachios are the best nut sources of bioactive ingredients with cardioprotective properties.