The cardioprotective effects of nuts are well established. However, the positive impacts of nuts in preventing CVD at a younger age, a condition known as premature coronary artery disease (PCAD), is still debated. Therefore, we aim to determine the association between nuts and PCAD occurrence and its severity in different Iranian ethnicities.

This case–control study was conducted within the framework of the Iran-premature coronary artery disease (I-PAD) study, an ongoing multi-centric study on Iranian patients of different ethnicities.

This multi-centric case–control study was conducted in among 3253 persons under the age of 70 years in women and 60 years in men from different ethnicities in Iran.

Information on nut consumption was collected using a validated FFQ. Subjects were selected from among the candidates for angiography. Cases were those whose coronary angiography showed stenosis of more than 75 % in at least one vessel or more than 50 % of the left main artery, while the control group participants had normal angiography results.

In the crude model, compared to the first quartile, the highest quartile of nut consumption was significantly associated with a lower risk of PCAD (OR = 0·26, 95 % CI (0·21, 0·32); Pfor trend = 0·001). In the top quartile of nut intake, a substantial decrease in PCAD was observed after controlling for putative confounders (OR = 0·32; 95 % CI (0·24, 0·43); Pfor trend = 0·001). Additionally, a 75 % decrease in the risk of severe PCAD was observed in the participants in the highest quartile of nut intake.

A significant inverse association was observed between nut intake and the risk and severity of PCAD in the Iranian population. Large-scale clinical trials are required to confirm these findings.

To identify ultra-processed foods (UPF) contribution to daily energy and nutrient intake in Iranians and examine whether UPF intake is associated with nutrient profile and diet quality.

In this cross-sectional study, a validated FFQ was used to evaluate usual dietary intake over the preceding year. NOVA system was applied to categorise foods based on their levels of processing. Diet quality was evaluated using the nutrient adequacy ratio (NAR), Nutrient Rich Food Index (NRF) and hybrid nutrient density.

The LIPOKAP study conducted in five cities of Iran (Isfahan, Birjand, Bandar Abbas, Kermanshah and Shahrekord).

A total of 1994 adults aged ≥18 years were recruited using stratified multistage random cluster sampling method.

UPF were responsible for 8·5 % of daily energy intake. In the adjusted model, UPF consumption was inversely associated with carbohydrate, protein, refined and whole grains, fibre, fruit and meat, but was positively linked to energy, total fat, saturated and trans fatty acids and cholesterol. Compared with those in the lowest tertile, individuals in the highest tertile of UPF had smaller NAR for Ca, Mg, Zn, Fe, phosphorus, thiamin, niacin, folate and vitamin C. Both NRF and hybrid nutrient density decreased when the share of daily energy intake from UPF increased.

The higher consumption of UPF is associated with poorer diet quality and lower nutrient intake. It is recommended that UPF be replaced with minimally processed foods to improve diet quality and nutrient profile.

Dietary acid load (DAL) might contribute to change the levels of cardiometabolic risk factors; however, the results are conflicting. The present review was conducted to determine the relationship between DAL and cardiometabolic risk factors.

Systematic review and meta-analysis.

A systematic search was conducted in electronic databases including ISI Web of Science, PubMed/MEDLINE, Scopus and Google Scholar for observational studies which assessed cardiometabolic risk factors across DAL. Outcomes were lipid profile, glycaemic factors and anthropometric indices. Effect sizes were derived using a fixed- or random-effect model (DerSimonian–Laird). Also, subgroup analysis was performed to find the probable source of heterogeneity. Egger’s test was performed for finding any publication bias.

Thirty-one studies were included in the current review with overall sample size of 92 478. There was a significant relationship between systolic blood pressure (SBP; weighted mean difference (WMD) = 1·74 (95 % CI 0·25, 3·24) mmHg; P = 0·022; I2 = 95·3 %), diastolic blood pressure (DBP; WMD = 0·75 (95 % CI 0·07, 1·42) mmHg; P = 0·030; I2 = 80·8 %) and DAL in cross-sectional studies. Serum lipids, glycaemic parameters including fasting blood sugar, glycated Hb, serum insulin, homeostatic model assessment of insulin resistance and waist circumference had no significant relationship with DAL. No publication bias was found. BMI was not associated with DAL in both cross-sectional and cohort studies.

Higher DAL is associated with increased SBP and DBP. More studies are needed to find any relationship of DAL with lipid profile and glycaemic factors.

Vegetarian diets contain various anti-inflammatory components. We aimed to investigate the effects of vegetarianism on inflammatory biomarkers when compared with omnivores.

Systematic review and meta-analysis.

Literature search was conducted in Science Direct, Proquest, MEDLINE and Google Scholar up to June 2016. Summary estimates and corresponding 95 % CI were derived via the DerSimonian and Laird method using random effects, subgroup analyses were run to find the source of heterogeneity and a fixed-effect model examined between-subgroup heterogeneity.

Studies were included if they evaluated effects of any type of vegetarianism compared with omnivores on circulating levels of inflammatory biomarkers. No restriction was made in terms of language or the date of study publications.

Eighteen articles were included. Pooled effect size showed no difference in high-sensitivity C-reactive protein (hs-CRP) levels in vegetarians v. omnivores (Hedges’ g=−0·15; 95 % CI −0·35, 0·05), with high heterogeneity (I2=75·6 %, P<0·01). A subgroup analysis by minimum duration of vegetarianism showed that a minimum duration of 2 years vegetarianism was associated with lower hs-CRP levels v. omnivores (Hedges’ g=−0·29; 95 % CI −0·59, 0·01), with moderate heterogeneity (I2=68·9 %, P<0·01). No significant effect was found in studies using a minimum duration of 6 months of vegetarianism, with low heterogeneity. Vegetarianism was associated with increased IL-6 concentrations (0·21 pg/ml; 95 % CI 0·18, 0·25), with no heterogeneity (I2=0·0 %, P=0·60).

The meta-analysis provides evidence that vegetarianism is associated with lower serum concentrations of hs-CRP when individuals follow a vegetarian diet for at least 2 years. Further research is necessary to draw appropriate conclusions regarding potential associations between vegetarianism and IL-6 levels. A vegetarian diet might be a useful approach to manage inflammaging in the long term.

To examine the relationship between dietary energy density (DED) and risk of metabolic syndrome (MetS), its components and inflammatory markers.

Cross-sectional study. Dietary intakes were assessed using a validated dish-based semi-quantitative FFQ. DED was calculated by dividing energy intake (kcal/d) by the total weight of foods only (g/d). MetS was defined based on the National Cholesterol Education Program Adult Treatment Panel III criteria. All associations were examined in the quartiles of DED, with higher quartiles indicating more energy-dense diets.

Isfahan, Iran.

Female nurses (n 1036) aged >30 years.

After controlling for potential confounders, individuals in the top quartile of DED had 78 % greater chance of MetS compared with those in the first (OR=1·78; 95 % CI 1·36, 2·98; P<0·001). Individuals in the highest quartile of DED were more likely to be abdominally obese (OR=1·51; 95 % CI 1·00, 2·63) and have hypertriacylglycerolaemia (OR=2·95; 95 % CI 1·58, 3·91) and low HDL cholesterol levels (OR=1·36; 95 % CI 1·17, 2·54) compared with those in the lowest quartile. Mean concentration of plasma high-sensitivity C-reactive protein (hs-CRP) across increasing quartiles of DED was 1·7, 1·7, 2·0, 2·4 mg/l (P for trend=0·04). Such increasing concentrations across increasing quartiles of DED were also seen for TNF-α (4·1, 4·5, 4·5, 4·8 ng/l; P for trend=0·03) and IL-6 (1·6, 1·6, 1·5, 2·5 ng/l; P for trend <0·01).

Consumption of high-energy-dense foods was associated with increased chance of MetS, most of its features and inflammatory markers including hs-CRP, TNF-α and IL-6.