Red meat consumption and risk of cardiovascular diseases-is increased iron load a possible link?

Associations of dietary iron intake with cardiovascular disease risk and dyslipidemia among Chinese adults

BACKGROUND

Whether iron intake can affect cardiovascular disease (CVD) and dyslipidemia is controversial. However, few studies have focused on reducing the risk of CVD in people at risk for dyslipidemia. This study explored the linear relationship and possible nonlinear relationship between CVD and dyslipidemia.

METHODS

Dietary data were obtained from the China Health and Nutrition Survey between 2004 and 2015. The survey included 8173 participants older than 18 years. CVD risk was estimated by the Framingham risk score (FRS). Logistic regression analysis was used to determine whether iron intake affects CVD incidence and lipid profiles. The nonlinear association was tested with restricted cubic splines (RCSs).

RESULTS

For males, higher total iron intake [the fifth quintile (Q) vs. Q1 odds ratio (OR): 0.335, 95% confidence interval (CI): 0.248-0.453], heme iron intake (OR: 0.679, 95% CI: 0.492-0.937) and non-heme iron intake (OR: 0.362, 95% CI: 0.266-0.492) reduced CVD incidence. Heme iron intake increased high low-density lipoprotein cholesterol (LDL-C) (OR: 1.786, 95% CI: 1.226-2.602), high total cholesterol (TC) (OR: 2.404, 95% CI: 1.575-3.669), high triglyceride (TG) (OR: 1.895, 95% CI: 1.423-2.523), and low apolipoprotein A1/apolipoprotein B (ApoA-1/ApoB) risk (OR: 1.514, 95% CI: 1.178-1.945). Moderate non-heme iron intake reduced high-density lipoprotein cholesterol (HDL-C) incidence (Q5 vs. Q1 OR: 0.704, 95% CI: 0.507-0.979). For females, higher total iron intake (Q5 vs. Q1 OR: 0.362, 95% CI: 0.266-0.492) and non-heme iron intake (OR: 0.347, 95% CI: 0.154-0.781) reduced CVD incidence. Heme iron intake increased high LDL-C (OR: 1.587, 95% CI: 1.160-2.170) and high TC incidence (OR: 1.655, 95% CI: 1.187-2.309).

CONCLUSIONS

Men, especially those at risk of developing dyslipidemia, should consume non-heme rather than heme iron to reduce CVD incidence. For women, increased heme iron intake did not reduce CVD incidence. Therefore, women should minimize their heme iron intake to prevent dyslipidemia.

Causal Association of Iron Status With Functional Outcome After Ischemic Stroke

BACKGROUND

Iron status has been associated with functional outcomes after ischemic stroke (IS). Nonetheless, this association may be affected by confounders. We perform Mendelian randomization to clarify the causal association between iron status and functional outcome after IS.

METHODS

We obtained summary-level statistics related to iron status biomarkers from a meta-analysis of a gene-wide association study conducted by the Genetics of Iron Status Consortium, which included 11 discovery cohorts and 8 replication cohorts. We also took genetic variants related to 4 biomarkers of iron status from combining gene-wide association study results of Iceland, the United Kingdom, and Denmark to perform a replicate Mendelian randomization analysis. This data set included 4 iron status biomarkers, namely, ferritin, total iron binding capacity, iron, and transferrin saturation (TSAT). The confounders in these data sets have been adjusted to mitigate the collider bias. We acquired summary statistics data sets for functional outcomes following IS from the gene-wide association study meta-analysis conducted by the Genetics of Ischemic Stroke Functional Outcome Consortium. The genetic estimates for functional outcomes at 90 days after IS were evaluated by the modified Rankin Scale score, including 3741 cases with good functional outcomes (modified Rankin Scale score, 0-2) and 2280 subjects with poor functional outcomes poststroke (modified Rankin Scale score, 3-6). Inverse variance weighting was used as the primary method, complemented by sensitivity analyses for pleiotropy and increasing robustness.

RESULTS

Reported with odds ratios (ORs) of stroke outcome with per SD unit increase in genetically determined iron status biomarker, TSAT and iron were associated with poor functional outcome after IS (TSAT: OR, 1.36 [95% CI, 1.23-1.50]; P=2.27×10-9; iron: OR, 1.44 [95% CI, 1.13-1.85]; P=0.0033). In replicate Mendelian randomization analysis, the detrimental effects of iron on poor functional outcome after IS remained stable (OR, 1.60 [95% CI, 1.24-2.08]; P=0.0003). In the meta-analysis, iron and TSAT were associated with poor functional outcomes after IS (TSAT: ORmeta, 1.35 [95% CI, 1.23-1.48]; iron: ORmeta, 1.51 [95% CI, 1.27-1.81]). Through sensitivity analyses and reverse Mendelian randomization analyses, we confirmed the robustness of the results.

CONCLUSIONS

Our study provides evidence suggesting a potential causal relationship between iron status and poor functional outcomes after IS. Future studies are required to illuminate the underlying mechanism.

Lipid metabolism reprogramming in cardiac fibrosis

Cardiac fibrosis is a critical pathophysiological process that occurs with diverse types of cardiac injury. Lipids are the most important bioenergy substrates for maintaining optimal heart performance and act as second messengers to transduce signals within cardiac cells. However, lipid metabolism reprogramming is a double-edged sword in the regulation of cardiomyocyte homeostasis and heart function. Moreover, lipids can exert diverse effects on cardiac fibrosis through different signaling pathways. In this review, we provide a brief overview of aberrant cardiac lipid metabolism and recent progress in pharmacological research targeting lipid metabolism alterations in cardiac fibrosis.

Diet-Attributable Greenhouse Gas Emissions and Acute Myocardial Infarction in Costa Rica Heart Study

Adopting sustainable dietary patterns is essential for planetary and human health. As data to address this issue are lacking in Latino populations, this study examined the association between diet-attributable greenhouse gas emissions (GHGEs) and myocardial infarction (MI) in a Costa Rica Heart Study. This analysis included 1817 cases of a first non-fatal acute MI during hospitalization and their matched population-based controls, by age, sex, and area of residence. A validated food frequency questionnaire was used to quantify habitual dietary intake and diet-attributable GHGEs (kg CO2 equivalent (eq.)/year). Due to the matching design, conditional logistic regression was used. Red meat consumption contributed approximately 50% to the total diet-attributable GHGEs among both cases and controls. Higher diet-attributable GHGEs were associated with increased odds of acute MI. The odds of MI were 63% higher (OR = 1.63; 95% CI 1.20-2.21) among participants in the highest quintile (median diet-attributable GHGEs = 6247 kg CO2 eq./year) compared to the lowest quintile (median diet-attributable GHGEs = 2065 kg CO2 eq./year). An increasing linear trend in the odds of acute MI and diet-attributable GHGEs was detected (p-trend 0.0012). These findings highlight the importance of reducing red meat consumption to sustainably mitigate the incidence of MI and improve planetary health.

Association between soft drink consumption and carotid atherosclerosis in a large-scale adult population: The TCLSIH cohort study

BACKGROUND AND AIMS

Carotid atherosclerosis indicates an increased risk for cardiac-cerebral vascular disease. Given the pattern of consumption in China, sugar-sweetened beverage is the main type of soft drink consumed. As soft drinks contain a high amount of fructose, they may be a risk factor of carotid atherosclerosis. A prospective cohort study was conducted to investigate the association between soft drink consumption and the incidence of carotid atherosclerosis in a Chinese adult population.

METHODS AND RESULTS

A total of 3828 participants (men: 2007 and women: 1821) were included. Carotid atherosclerosis was measured by using ultrasonography and was defined by increased carotid intima-media thickness and/or carotid plaques. Soft drink consumption was assessed using a validated food frequency questionnaire. Cox proportional hazards regression analysis was used to assess the association of soft drink consumption categories with the incidence of carotid atherosclerosis. During a mean follow-up of 3.20 years, 1009 individuals of the 3828 eligible participants developed carotid atherosclerosis. After adjusting for potential confounding factors, we compared the higher levels to the lowest level of soft drink consumption in women, and we estimated the multivariable hazard ratios and 95% confidence intervals of incident carotid atherosclerosis to be 1.09 (0.80, 1.50), and 1.56 (1.14, 2.13) (P for trend <0.05). However, there was no significant association between soft drink consumption and the incidence of carotid atherosclerosis in men or total population.

CONCLUSION

The result indicated that soft drink consumption was associated with a higher incidence of carotid atherosclerosis in women.

TRIAL REGISTERED

UMIN Clinical Trials Registry.

TRIAL REGISTRATION NUMBER

UMIN000027174. TRIAL REGISTRATION WEBSITE: https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000031137.

Red meat consumption, cardiovascular diseases, and diabetes: a systematic review and meta-analysis

AIMS

Observational studies show inconsistent associations of red meat consumption with cardiovascular disease (CVD) and diabetes. Moreover, red meat consumption varies by sex and setting, however, whether the associations vary by sex and setting remains unclear.

METHODS AND RESULTS

This systematic review and meta-analysis was conducted to summarize the evidence concerning the associations of unprocessed and processed red meat consumption with CVD and its subtypes [coronary heart disease (CHD), stroke, and heart failure], type two diabetes mellitus (T2DM), and gestational diabetes mellitus (GDM) and to assess differences by sex and setting (western vs. eastern, categorized based on dietary pattern and geographic region). Two researchers independently screened studies from PubMed, Web of Science, Embase, and the Cochrane Library for observational studies and randomized controlled trials (RCTs) published by 30 June 2022. Forty-three observational studies (N = 4 462 810, 61.7% women) for CVD and 27 observational studies (N = 1 760 774, 64.4% women) for diabetes were included. Red meat consumption was positively associated with CVD [hazard ratio (HR) 1.11, 95% confidence interval (CI) 1.05 to 1.16 for unprocessed red meat (per 100 g/day increment); 1.26, 95% CI 1.18 to 1.35 for processed red meat (per 50 g/day increment)], CVD subtypes, T2DM, and GDM. The associations with stroke and T2DM were higher in western settings, with no difference by sex.

CONCLUSION

Unprocessed and processed red meat consumption are both associated with higher risk of CVD, CVD subtypes, and diabetes, with a stronger association in western settings but no sex difference. Better understanding of the mechanisms is needed to facilitate improving cardiometabolic and planetary health.

Mendelian randomization study reveals a causal relationship between serum iron status and coronary heart disease and related cardiovascular diseases

Background

Growing observational studies have shown that abnormal systemic iron status is associated with Coronary heart disease (CHD). However, these results from observational studies was not entirely consistent.It remains unclear whether this relationship represents causality.It is necessary to explore the causal relationship between iron status and CHD and related cardiovascular diseases (CVD).

Objective

We aimed to investigate the potential casual relationship between serum iron status and CHD and related CVD using a two-sample Mendelian randomization (MR) approach.

Methods

Genetic statistics for single nucleotide polymorphisms (SNPs) between four iron status parameters were identified in a large-scale genome-wide association study (GWAS) conducted by the Iron Status Genetics organization. Three independent single nucleotide polymorphisms (SNPs) (rs1800562, rs1799945, and rs855791) aligned with four iron status biomarkers were used as instrumental variables. CHD and related CVD genetic statistics We used publicly available summary-level GWAS data. Five different MR methods random effects inverse variance weighting (IVW), MR Egger, weighted median, weighted mode, and Wald ratio were used to explore the causal relationship between serum iron status and CHD and related CVD.

Results

In the MR analysis, we found that the causal effect of serum iron (OR = 0.995, 95% CI = 0.992-0.998, p = 0.002) was negatively associated with the odds of coronary atherosclerosis (AS). Transferrin saturation (TS) (OR = 0.885, 95% CI = 0.797-0.982, p = 0.02) was negatively associated with the odds of Myocardial infarction (MI).

Conclusion

This MR analysis provides evidence for a causal relationship between whole-body iron status and CHD development. Our study suggests that a high iron status may be associated with a reduced risk of developing CHD.

Assessment of Vascular Function in Response to High-Fat and Low-Fat Ground Beef Consumption in Men

Red meat is stigmatized as an unhealthy protein choice; however, its impacts on vascular function have not been evaluated. We aimed to measure the vascular impact of adding either low-fat (~5% fat) ground beef (LFB) or high-fat (~25% fat) ground beef (HFB) to a habitual diet in free-living men. Twenty-three males (39.9 ± 10.8 years, 177.5 ± 6.7 cm, 97.3 ± 25.0 kg) participated in this double-blind crossover study. Assessment of vascular function and aerobic capacity were measured at entry and in the last week of each intervention and washout period. Participants then completed two 5-week dietary interventions (LFB or HFB; 5 patties/week) in a randomized order with a 4-week washout. Data were analyzed via 2 × 2 repeated-measures ANOVA (p < 0.05). The HFB intervention improved FMD relative to all other time points, while lowering systolic (SBP) and diastolic blood pressure (DBP) relative to entry. Neither the HFB nor the LFB altered pulse wave velocity. The addition of either low- or high-fat ground beef did not negatively alter vascular function. In fact, consuming HFB improved FMD and BP values, which may be mediated by lowering LDL-C concentrations.

Iron deficiency and cardiovascular disease

Iron deficiency (ID) is common in patients with cardiovascular disease. Up to 60% of patients with coronary artery disease, and an even higher proportion of those with heart failure (HF) or pulmonary hypertension have ID; the evidence for cerebrovascular disease, aortic stenosis and atrial fibrillation is less robust. The prevalence of ID increases with the severity of cardiac and renal dysfunction and is probably more common amongst women. Insufficient dietary iron, reduced iron absorption due to increases in hepcidin secondary to the low-grade inflammation associated with atherosclerosis and congestion or reduced gastric acidity, and increased blood loss due to anti-thrombotic therapy or gastro-intestinal or renal disease may all cause ID. For older people in the general population and patients with HF with reduced ejection fraction (HFrEF), both anaemia and ID are associated with a poor prognosis; each may confer independent risk. There is growing evidence that ID is an important therapeutic target for patients with HFrEF, even if they do not have anaemia. Whether this is also true for other HF phenotypes or patients with cardiovascular disease in general is currently unknown. Randomized trials showed that intravenous ferric carboxymaltose improved symptoms, health-related quality of life and exercise capacity and reduced hospitalizations for worsening HF in patients with HFrEF and mildly reduced ejection fraction (<50%). Since ID is easy to treat and is effective for patients with HFrEF, such patients should be investigated for possible ID. This recommendation may extend to other populations in the light of evidence from future trials.

Exercise modulates the immune system in cardiorespiratory disease patients: Implications for clinical practice during the COVID-19 pandemic

BACKGROUND

Patients with cardiorespiratory problems often suffer from systemic inflammation. Stress due to the disease and continuous inflammation can undermine the success of the rehabilitation program.

OBJECTIVE

This review has been undertaken primarily to understand the effectiveness of exercise training on the immune system in individuals undergoing cardiorespiratory rehabilitation and its implications for further management during the COVID-19 pandemic.

METHODS

Assessors analyzed related studies identified in the MEDLINE, PROQUEST, PUBMED, Cochrane Library, CINAHL, EMBASE, Google Scholar, Physiotherapy Evidence, and Science Direct databases. The studies were divided into groups focused on the effect of exercise on blood leukocytes, the anti-inflammatory effect, and the role of nutrition and exercise in resolving inflammation.

RESULTS

Twenty-eight studies were included in this review. The number of studies included in each section was as follows: the effects of exercise training on leukocytes in cardiorespiratory conditions (n = 8), anti-inflammatory effect (n = 6), and the role of nutrition and exercise in resolving inflammation (n = 14). The bias risk assessment showed poor internal validity; most included studies were assigned no and unclear descriptors.

CONCLUSIONS

Substantive evidence is presented that emphasizes the role of moderate-intensity exercise in boosting the immune system in patients with cardiorespiratory diseases. Exercise has anti-inflammatory effects that are vital for overall well-being and resolving longstanding inflammation. Individuals with an active lifestyle had a better pathogen immune response than more sedentary individuals. Our findings highlight the current need to investigate the long-term effects of cardiorespiratory rehabilitation programs.

Association between iron exposures and stroke in adults: Results from National Health and Nutrition Examination Survey during 2007-2016 in United States

The available findings on the association between iron status and risk of stroke remain controversial. We used multivariable logistic regression and restricted cubic spline models to explore the association between iron exposures and risk of stroke in the US National Health and Nutrition Examination Survey (NHANES 2007-2016, n = 24,627). A total of 941 (3.82%) stroke cases were identified in this study. In women, the ORs with 95% CIs of prevalence of stroke were 0.92 (0.65-1.28), 0.66 (0.44-0.98) and 0.72 (0.49-1.08) across quartiles 2-4 compared with quartile 1 of iron intake, respectively. An inverse and L-shaped association between iron intake and risk of stroke in women was observed, and the curve plateaued at 20 mg/day. However, neither serum iron concentrations nor iron intake were significantly associated with riskof stroke in men. Our study found that iron intake was inversely associated with risk of stroke in a sex-dependent fashion.

Associations of the consumption of unprocessed red meat and processed meat with the incidence of cardiovascular disease and mortality, and the dose-response relationship: A systematic review and meta-analysis of cohort studies

OBJECTIVES

The aim of this study was to examine the associations of unprocessed red meat and processed meat consumption with cardiovascular disease (CVD) incidence and mortality, and the dose-response relationship.

METHODS

Published literature was retrieved through a structured search of 10 electronic databases: MEDLINE/PubMed, Scopus, SciELO, LILACS, ScienceDirect, Web of Science, Cochrane (CENTRAL), WHOLIS, PAHO and Embase, without language or year of publication restrictions. In addition, we searched the references of published studies. This systematic review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyzes: The PRISMA Statement.

RESULTS

Twenty-one prospective cohort studies were included in the systematic review. The CVDs evaluated in the inserted studies were stroke, heart failure (HF) and coronary heart disease (CHD). Considering the heterogeneity found in the studies, for the meta-analysis, 9 articles were included. The results presented in the meta-analysis of the association of consumption of unprocessed red meat and CVD indicated that there was a significant association with total stroke incidence (RR 1.10; 95%; CI 1.01 to 1.19; p = 0.02). There was no association with Ischemic stroke incidence, nor CHD Mortality with consumption of unprocessed red meat. However, for Hemorrhagic Stroke Mortality the assessment in the consumption of unprocessed red meat showed an association of protection for women (RR 0.64; 95%; CI 0.45 to 0.91; p = 0.01). As for the results of the meta-analysis of the association between consumption of processed meat and CVD, they indicated that there was a significant association with total stroke incidence (RR 1.17; 95%; CI 1.08 to 1.26; p < 0.0001). There was no association with Ischemic stroke, nor with CHD Mortality with consumption of processed meat. Some studies that showed no association of risk, presented a significant linear trend dose response for the association of the consumption of unprocessed red meat (Bernstein et al. 2010; Nagao et al. 2012) or processed meat (Bernstein et al. 2012) and CVD.

CONCLUSION

According to the results found in the meta-analysis, the consumption of unprocessed red meat and processed meat are associated with the incidence of stroke, however, no positive association was observed in relation to mortality from CVD. This systematic review and meta-analysis protocol was registered on the PROSPERO (number: CRD42019100914).

Association of Zinc Deficiency with Development of CVD Events in Patients with CKD

Deficiency of the micronutrient zinc is common in patients with chronic kidney disease (CKD). The aim of this review is to summarize evidence presented in literature for consolidation of current knowledge regarding zinc status in CKD patients, including those undergoing hemodialysis. Zinc deficiency is known to be associated with various risk factors for cardiovascular disease (CVD), such as increased blood pressure, dyslipidemia, type 2 diabetes mellitus, inflammation, and oxidative stress. Zinc may protect against phosphate-induced arterial calcification by suppressing activation of nuclear factor kappa light chain enhancer of activated B. Serum zinc levels have been shown to be positively correlated with T₅₀ (shorter T₅₀ indicates higher calcification propensity) in patients with type 2 diabetes mellitus as well as those with CKD. Additionally, higher intake of dietary zinc was associated with a lower risk of severe abdominal aortic calcification. In hemodialysis patients, the beneficial effects of zinc supplementation in relation to serum zinc and oxidative stress levels was demonstrated in a meta-analysis of 15 randomized controlled trials. Thus, evidence presented supports important roles of zinc regarding antioxidative stress and suppression of calcification and indicates that zinc intake/supplementation may help to ameliorate CVD risk factors in CKD patients.

Long-term association of red meat consumption and lipid profile: A 13-year prospective population-based cohort study

OBJECTIVES

The long-term associations between red meat consumption and lipid profile are not completely known. This longitudinal study assessed the association of red meat consumption with lipid profile in healthy Iranian adults using repeated measurements of red meat intake.

METHODS

The population-based longitudinal study was conducted within the framework of the Isfahan Cohort Study on a subsample of 1376 healthy adults, aged ≥35 y, for whom complete information was available in all three phases of the study. A simplified qualitative 48-item food frequency questionnaire, blood pressure, anthropometric measurements, and fasting serum lipids and blood sugar were evaluated in three phases. Mixed-effects linear regression was applied to examine the longitudinal associations between red meat consumption and lipid profile.

RESULTS

After adjustment for potential confounders, each single-serving increase in red meat and organ meat consumption was significantly associated with an increment in triacylglycerol (β = 6.30; 95% confidence interval [CI], 3.97-8.63), total cholesterol (β = 3.03; 95% CI, 2.02-4.04), low-density lipoprotein (β = 3.40; 95% CI, 2.64-4.17), high-density lipoprotein (β = 0.60; 95% CI, 0.28-0.93), ratio of low-density to high-density lipoprotein (β = 0.03; 95% CI, 0.01-0.05), and non-high-density lipoprotein (β = 2.42; 95% CI, 1.41-3.43). However, processed meat consumption had no significant association with lipid profile.

CONCLUSIONS

Total red meat intake had a significant, direct association with lipid profile after a 13-year follow-up period in a cohort of the healthy Iranian population.

Top 10 dietary strategies for atherosclerotic cardiovascular risk reduction

Poor dietary quality has surpassed all other mortality risk factors, accounting for 11 million deaths and half of CVD deaths globally. Implementation of current nutrition recommendations from the American Heart Association (AHA), American College of Cardiology (ACC) and the National Lipid Association (NLA) can markedly benefit the primary and secondary prevention of atherosclerotic cardiovascular disease (ASCVD). These include: 1) incorporate nutrition screening into medical visits; 2) refer patients to a registered dietitian nutritionist (RDN) for medical nutrition therapy, when appropriate, for prevention of ASCVD; 3) follow ACC/AHA Nutrition and Diet Recommendations for ASCVD prevention and management of overweight/obesity, type 2 diabetes and hypertension; 4) include NLA nutrition goals for optimizing low-density lipoprotein cholesterol (LDL-C) and non-high-density lipoprotein cholesterol (non-HDL-C) and reducing ASCVD risk; 5) utilize evidence-based heart-healthy eating patterns for improving cardiometabolic risk factors, dyslipidemia and ASCVD risk; 6) implement ACC/AHA/NLA nutrition and lifestyle recommendations for optimizing triglyceride levels; 7) understand the impact of saturated fats, trans fats, omega-3 and omega-6 polyunsaturated fats and monounsaturated fats on ASCVD risk; 8) limit excessive intake of dietary cholesterol for those with dyslipidemia, diabetes and at risk for heart failure; 9) include dietary adjuncts such as viscous fiber, plant sterols/stanols and probiotics; and 10) implement AHA/ACC and NLA physical activity recommendations for the optimization of lipids and prevention of ASCVD. Evidence on controversies pertaining to saturated fat, processed meat, red meat, intermittent fasting, low-carbohydrate/very-low-carbohydrate diets and caffeine are discussed.

Predictive Value of Serum Ferritin in Combination with Alanine Aminotransferase and Glucose Levels for Noninvasive Assessment of NAFLD: Fatty Liver in Obesity (FLiO) Study

The identification of affordable noninvasive biomarkers for the diagnosis and characterization of nonalcoholic fatty liver disease (NAFLD) is a major challenge for the research community. This study aimed to explore the usefulness of ferritin as a proxy biomarker of NAFLD condition, alone or in combination with other routine biochemical parameters. Subjects with overweight/obesity and ultrasound-confirmed liver steatosis (n = 112) from the Fatty Liver in Obesity (FLiO) study were assessed. The hepatic evaluation considered magnetic resonance imaging, ultrasonography, and credited routine blood liver biomarkers. Anthropometry and body composition, dietary intake (by means of a validated 137-item food frequency questionnaire), and specific biochemical markers were also determined. Serum ferritin levels were analyzed using a chemiluminescent microparticle immunoassay kit. Lower serum ferritin concentrations were associated with general better liver health and nutritional status. The evaluation of ferritin as a surrogate of liver damage by means of quantile regression analyses showed a positive association with alanine aminotransferase (ALT) (β = 19.21; p ≤ 0.001), liver fat content (β = 8.70; p = 0.008), and hepatic iron (β = 3.76; p ≤ 0.001), after adjusting for potential confounders. In receiver operating characteristic (ROC) analyses, the panel combination of blood ferritin, glucose, and ALT showed the best prediction for liver fat mass (area under the curve (AUC) 0.82). A combination of ferritin and ALT showed the higher predictive ability for estimating liver iron content (AUC 0.73). This investigation demonstrated the association of serum ferritin with liver health as well as with glucose and lipid metabolism markers in subjects with NAFLD. Current findings led to the identification of ferritin as a potential noninvasive predictive biomarker of NAFLD, whose surrogate value increased when combined with other routine biochemical measurements (glucose/ALT).

Role of Carbon Monoxide in Host-Gut Microbiome Communication

Nature is full of examples of symbiotic relationships. The critical symbiotic relation between host and mutualistic bacteria is attracting increasing attention to the degree that the gut microbiome is proposed by some as a new organ system. The microbiome exerts its systemic effect through a diverse range of metabolites, which include gaseous molecules such as H₂, CO₂, NH₃, CH₄, NO, H₂S, and CO. In turn, the human host can influence the microbiome through these gaseous molecules as well in a reciprocal manner. Among these gaseous molecules, NO, H₂S, and CO occupy a special place because of their widely known physiological functions in the host and their overlap and similarity in both targets and functions. The roles that NO and H₂S play have been extensively examined by others. Herein, the roles of CO in host-gut microbiome communication are examined through a discussion of (1) host production and function of CO, (2) available CO donors as research tools, (3) CO production from diet and bacterial sources, (4) effect of CO on bacteria including CO sensing, and (5) gut microbiome production of CO. There is a large amount of literature suggesting the "messenger" role of CO in host-gut microbiome communication. However, much more work is needed to begin achieving a systematic understanding of this issue.

Ambient fine particulate matter pollution and years of life lost from cardiovascular diseases in 48 large Chinese cities: Association, effect modification, and additional life gain

Existing evidence on the associations between fine particulate matter (PM_2.5) and years of life lost (YLL) from cardiovascular diseases (CVD) is limited and inconclusive, and the role of potential modifiers, especially those at city-level, is not fully understood. In this study, a time-series study was conducted in 48 large Chinese cities from 2013 to 2017. Generalized additive model coupled with random effects model were used to estimate national-average associations of PM_2.5 with YLL. Effect modification by individual- and city-level characteristics obtained by linking with China Chronic Disease and Risk Factors Surveillance was explored. Moreover, additional life gain was evaluated under scenario where PM_2.5 concentration would be reduced. For 10 μg/m³ increase in PM_2.5 concentration at lag01 day, the relative increment of YLL was 0.22% from CVD, 0.20% from ischemic heart disease, 0.26% from stroke, 0.23% from hemorrhagic stroke, and 0.31% from ischemic stroke. Some associations were stronger in elder and less educated people, warm season, as well as cities characterized by higher temperature and prevalence of binge drinking and excess red meat intake, or lower PM_2.5 and prevalence of usual exercise. Additional life gain attributable to avoidable YLL from CVD was estimated to be 0.08 year if PM_2.5 concentration could fall to the standard recommended by World Health Organization (25 μg/m³). This large epidemiological investigation demonstrated robust evidence of short-term associations between PM_2.5 exposure and YLL from CVD. Potential modifiers should be considered to develop efficient intervention strategies. Implementation of more stringent standard is beneficial to alleviate YLL caused by PM_2.5.

Association between dietary zinc intake and abdominal aortic calcification in US adults

BACKGROUND

In animal studies, zinc supplementation inhibited phosphate-induced arterial calcification. We tested the hypothesis that higher intake of dietary zinc was associated with lower abdominal aortic calcification (AAC) among adults in the USA. We also explored the associations of AAC with supplemental zinc intake, total zinc intake and serum zinc level.

METHODS

We performed cross-sectional analyses of 2535 participants from the National Health and Nutrition Examination Survey 2013-14. Dietary and supplemental zinc intakes were obtained from two 24-h dietary recall interviews. Total zinc intake was the sum of dietary and supplemental zinc. AAC was measured using dual-energy X-ray absorptiometry in adults ≥40 years of age and quantified using the Kauppila score system. AAC scores were categorized into three groups: no AAC (AAC = 0, reference group), mild-moderate (AAC >0-≤6) and severe AAC (AAC >6).

RESULTS

Dietary zinc intake (mean ± SE) was 10.5 ± 0.1 mg/day; 28% had AAC (20% mild-moderate and 8% severe), 17% had diabetes mellitus and 51% had hypertension. Higher intake of dietary zinc was associated with lower odds of having severe AAC. Per 1 mg/day higher intake of dietary zinc, the odds of having severe AAC were 8% lower [adjusted odds ratio 0.92 (95% confidence interval 0.86-0.98), P = 0.01] compared with those without AAC, after adjusting for demographics, comorbidities and laboratory measurements. Supplemental zinc intake, total zinc intake and serum zinc level were not associated with AAC.

CONCLUSIONS

Higher intake of dietary zinc was independently associated with lower odds of having severe AAC among noninstitutionalized US adults.

Principais Direcionadores de Compra de Carnes em Hipermercados

RESUMO Objetivo: a urbanização e migração para os grandes centros tem provocado mudanças no comportamento dos consumidores de carnes, não somente no que se refere a escolha do produto, mas também, ao processo de compra. Neste sentido, fatores como proximidade, disponibilidade do produto, e preço são relacionados como fatores que definem compras. Na tentativa de ampliar o entendimento sobre o que os consumidores consideram importante, este trabalho objetiva analisar os principais fatores associados ao consumo das carnes bovina, suína e de frango no Distrito Federal, Brasil. Métodos: a pesquisa foi realizada em três redes distintas de hipermercados. Realizou-se uma avaliação socioeconômica dos entrevistados, seguida da aplicação de um Survey, através de sentenças afirmativas estruturadas, categorizadas em dimensões sociocultural, econômica, saúde/alimento e ambiente. As sentenças foram avaliadas através da Escala Likert de sete pontos. Os dados socioeconômicos dos entrevistados foram analisados por testes de Qui-quadrado e as respostas obtidas por meio da Escala Likert foram transformados em Mean Item Score (MIS). Resultados e Conclusões: os resultados indicaram que o controle de qualidade de exposição das carnes nos supermercados e a praticidade de encontrar o mesmo tipo de carne em vários locais são os principais influenciadores de tomada de decisão de compra pelos consumidores.

Trace Elements in Home-Processed Food Obtained from Unconventional Animals

Wild animals have been used as food since ancient times and, currently, the consumption of unconventional animals is increasing worldwide. The process of cooking meat using traditional recipes includes a variety of ingredients, which can influence the total metal intake from the diet. In this study, the concentrations of eight essential (Fe, Zn, Cu, Mn, Se, Ni, Mo, and Co) and six non-essential (Pb, Cd, Hg, Al, As, and Cr) trace elements were determined in home-processed food obtained from snails and from three common species of game animals (woodcock, pheasant, and hare), seasoned with anchovies, mushrooms, and different vegetables using inductively coupled plasma mass spectrometry (ICP-MS). In general, Fe was the most abundant trace element, ranging from 18 ± 8 µg/g in pheasant to 99 ± 76 µg/g in snail, and Co was the least abundant, ranging from 0.007 ± 0.003 µg/g in hare to 0.093 ± 0.048 µg/g in snail. Regarding the non-essential trace elements, Pb concentrations showed wide variations, reaching a concentration of 17.30 µg/g in hare, while Cd concentrations were higher in snail, ranging from 0.18 to 0.46 µg/g. These alternative food sources can offer an important contribution to the human nutritional requirements of essential trace elements, in particular of Fe. The high concentrations of Pb and Cd present in some samples should be considered as potentially dangerous for the consumers.

Influence of Alcohol and Red Meat Consumption on Life Expectancy: Results of 164 Countries from 1992 to 2013

Background: High consumption of red meat, which is carcinogenic to humans, and misuse or abuse of alcohol drinking increase premature death and shortened life expectancy. The aim of this study was to examine the association of alcohol and red meat consumption with life expectancy (LE) by analyzing data from 164 countries using an ecological approach. Design: This was a longitudinal ecological study using data from the United Nation’s (UN) Food and Agriculture Organization (FAO) for 164 countries over the period 1992–2013. In regression analysis, the relationship of alcohol and red meat consumption with LE was estimated using a pooled ordinary least squares regression model. Alcohol and red meat consumption were measured every 5 years. Results: The consumption of alcohol and red meat in high-income countries (HIC) was about 4 times (36.8–143.0 kcal/capita/day) and 5 times (11.2–51.9 kcal/capita/day) higher than that in low-income countries (LIC). Red meat and alcohol consumption had a negative estimated effect on LE in HIC (b = −1.616 p = < 0.001 and b = −0.615, p = 0.003). Alcohol consumption was negatively associated with LE for all income groups, while positive relationships were found for all estimates associated with gross national income (GNI). Conclusions: Red meat and alcohol consumption appeared to have a negative impact on LE in high-income countries (HIC) and upper-middle-income countries (UMIC), although it had no significant association with LE in low-income countries (LIC) or lower-middle-income countries (LMIC). This study suggests reviewing the policies on the gradual reduction of alcohol abuse and the high consumption of red meat, particularly HIC and UMIC.

Dysregulated Iron Metabolism-Associated Dietary Pattern Predicts an Altered Body Composition and Metabolic Syndrome

Diet plays an important role in the development of obesity and may contribute to dysregulated iron metabolism (DIM). A cross-sectional survey of 208 adults was conducted in Taipei Medical University Hospital (Taipei, Taiwan). A reduced-rank regression from 31 food groups was used for a dietary pattern analysis. DIM was defined as at least four of the following criteria: serum hepcidin (men >200 ng/mL and women >140 ng/mL), hyperferritinemia (serum ferritin of >300 ng/mL in men and >200 ng/mL in women), central obesity, non-alcoholic fatty liver disease, and two or more abnormal metabolic profiles. Compared to non-DIM patients, DIM patients were associated with an altered body composition and had a 4.52-fold (95% confidence interval (CI): (1.95–10.49); p < 0.001) greater risk of metabolic syndrome (MetS) after adjusting for covariates. A DIM-associated dietary pattern (high intake of deep-fried food, processed meats, chicken, pork, eating out, coffee, and animal fat/skin but low intake of steamed/boiled/raw foods and dairy products) independently predicted central obesity (odds ratio (OR): 1.57; 95% CI: 1.05–2.34; p < 0.05) and MetS (OR: 1.89; 95% CI: 1.07–3.35; p < 0.05). Individuals with the highest DIM pattern scores (tertile 3) had a higher visceral fat mass (%) (β = 0.232; 95% CI: 0.011–0.453; p < 0.05) but lower skeletal muscle mass (%) (β = −1.208; 95% CI: −2.177–−0.239; p < 0.05) compared to those with the lowest DIM pattern scores (tertile 1). In conclusion, a high score for the identified DIM-associated dietary pattern was associated with an unhealthier body composition and a higher risk of MetS.

Independent and combined effects of dietary iron composition and selected risk factors on the risk of NAFLD in a Chinese population

Iron is an essential mineral required for most forms of life. However, very little is known in relation to the different forms of dietary iron on the development of NAFLD. The aims of this study were to investigate the effects of iron intake from different food types on risk of NAFLD and whether this effect may be modified by other factors. We conducted a hospital-based case–control study including 1,273 NAFLD cases and 1,273 gender and age-matched controls. We conducted in-person interviews while participants completed a questionnaire on food habits. We assessed animal- and plant-derived intake of iron and fat. We observed that animal-derived iron intake (>4.16 mg/day) was positively associated with augmented NAFLD risk in a Chinese population (OR_adjusted = 1.66 in the highest quartile compared with the lowest, 95% confidence interval [CI] = 1.01–2.73). In contrast, a high consumption of iron (>16.87 mg/day) from plant-based foods was associated with a decreased NAFLD risk (ORadjusted = 0.61 in the highest quartile compared with the lowest; 95% CI = 0.40–0.935). In addition, high intake of fat or being overweight may exacerbate this effect. Reduced consumption of iron and fat from animal sources could reduce NAFLD risk, as would weight loss.

Normality, Naturalness, Necessity, and Nutritiousness of the New Meat Alternatives

In the West, meat is acceptable, tasty, delicious, palatable, and enjoyable. It has a well-established position in the consumers' food habits shaping the taste of the affluent eating culture and accepted as normal, natural, necessary, and nutritious. Although recent scientific evidence recognizes that meat has a high negative environmental impact, there is still lack of attention on the fact that we live on a planet with limited resources which need to be preserved. Part of this is a transition to more sustainable consumption habits and diets. This chapter examines the social readiness and acceptability of new meat alternatives as normal, natural, necessary, and nutritious amongst Gen Y and Gen Z consumers. It concludes that a reduction in meat consumption should be an essential part of creating a more sustainable diet in light of the projected increase of the world population, expected human health benefits, and improved environmental wellbeing of the planet.

Measurement of liver iron by magnetic resonance imaging in the UK Biobank population

The burden of liver disease continues to increase in the UK, with liver cirrhosis reported to be the third most common cause of premature death. Iron overload, a condition that impacts liver health, was traditionally associated with genetic disorders such as hereditary haemochromatosis, however, it is now increasingly associated with obesity, type-2 diabetes and non-alcoholic fatty liver disease. The aim of this study was to assess the prevalence of elevated levels of liver iron within the UK Biobank imaging study in a cohort of 9108 individuals. Magnetic resonance imaging (MRI) was undertaken at the UK Biobank imaging centre, acquiring a multi-echo spoiled gradient-echo single-breath-hold MRI sequence from the liver. All images were analysed for liver iron and fat (expressed as proton density fat fraction or PDFF) content using LiverMultiScan. Liver iron was measured in 97.3% of the cohort. The mean liver iron content was 1.32 ± 0.32 mg/g while the median was 1.25 mg/g (min: 0.85 max: 6.44 mg/g). Overall 4.82% of the population were defined as having elevated liver iron, above commonly accepted 1.8 mg/g threshold based on biochemical iron measurements in liver specimens obtained by biopsy. Further analysis using univariate models showed elevated liver iron to be related to male sex (p<10⁻¹⁶, r² = 0.008), increasing age (p<10⁻¹⁶, r² = 0.013), and red meat intake (p<10⁻¹⁶, r² = 0.008). Elevated liver fat (>5.6% PDFF) was associated with a slight increase in prevalence of elevated liver iron (4.4% vs 6.3%, p = 0.0007). This study shows that population studies including measurement of liver iron concentration are feasible, which may in future be used to better inform patient stratification and treatment.

Nutrition and Cardiovascular Health

Cardiovascular disease (CVD) is the leading cause of death in Western countries, representing almost 30% of all deaths worldwide. Evidence shows the effectiveness of healthy dietary patterns and lifestyles for the prevention of CVD. Furthermore, the rising incidence of CVD over the last 25 years has become a public health priority, especially the prevention of CVD (or cardiovascular events) through lifestyle interventions. Current scientific evidence shows that Western dietary patterns compared to healthier dietary patterns, such as the ‘Mediterranean diet’ (MeDiet), leads to an excessive production of proinflammatory cytokines associated with a reduced synthesis of anti-inflammatory cytokines. In fact, dietary intervention allows better combination of multiple foods and nutrients. Therefore, a healthy dietary pattern shows a greater magnitude of beneficial effects than the potential effects of a single nutrient supplementation. This review aims to identify potential targets (food patterns, single foods, or individual nutrients) for preventing CVD and quantifies the magnitude of the beneficial effects observed. On the other hand, we analyze the possible mechanisms implicated in this cardioprotective effect.

Iron Status and Risk of Stroke

Background and Purpose- Both iron deficiency and excess have been associated with stroke risk in observational studies. However, such associations may be attributable to confounding from environmental factors. This study uses the Mendelian randomization technique to overcome these limitations by investigating the association between genetic variants related to iron status and stroke risk. Methods- A study of 48 972 subjects performed by the Genetics of Iron Status consortium identified genetic variants with concordant relations to 4 biomarkers of iron status (serum iron, transferrin saturation, ferritin, and transferrin) that supported their use as instruments for overall iron status. Genetic estimates from the MEGASTROKE consortium were used to investigate the association between the same genetic variants and stroke risk. The 2-sample ratio method Mendelian randomization approach was used for the main analysis, with the MR-Egger and weighted median techniques used in sensitivity analyses. Results- The main results, reported as odds ratio (OR) of stroke per SD unit increase in genetically determined iron status biomarker, showed a detrimental effect of increased iron status on stroke risk (serum iron OR, 1.07; 95% CI, 1.01-1.14; [log-transformed] ferritin OR, 1.18; 95% CI, 1.02-1.36; and transferrin saturation OR, 1.06; 95% CI, 1.01-1.11). A higher transferrin, indicative of lower iron status, was also associated with decreased stroke risk (OR, 0.92; 95% CI, 0.86-0.99). Examining ischemic stroke subtypes, we found the detrimental effect of iron status to be driven by cardioembolic stroke. These results were supported in statistical sensitivity analyses more robust to the inclusion of pleiotropic variants. Conclusions- This study provides Mendelian randomization evidence that higher iron status is associated with increased stroke risk and, in particular, cardioembolic stroke. Further work is required to investigate the underlying mechanism and whether this can be targeted in preventative strategies.

Effects of Dietary Protein from Different Sources on Biotransformation, Antioxidation, and Inflammation in the Rat Liver

In this work, the effects of different sources of meat protein on liver metabolic enzymes were investigated. Rats were fed for 90 days with semisynthetic diets in which casein was fully replaced by isolated soybean, fish, chicken, pork, or beef proteins. Then, liver proteomics was performed using iTRAQ and LC-ESI-MS/MS. The results indicated that intake of meat protein diets significantly reduced the protein levels of CYP450s, GSTs, UGTs, and SULTs compared to those of the casein and soybean protein diet groups. The total antioxidant capacity and lipid peroxidation values did not differ between four meat protein diet groups and the casein diet group. However, GSH activity in the fish, chicken, and beef protein groups was significantly higher than those of the casein and soybean protein groups. The beef protein diet significantly upregulated the expression of immune-related proteins. The Keap1-Nrf2-ARE signaling pathway was suggested to involve the diet-mediated regulation of biotransformation, inflammation, and redox status.