Impact of Egg Consumption on Cardiovascular Risk Factors in Individuals with Type 2 Diabetes and at Risk for Developing Diabetes: A Systematic Review of Randomized Nutritional Intervention Studies

Low Carbon Sustainable Diet Choices-An Analysis of the Driving Factors behind Plant-Based Egg Purchasing Behavior

In the face of escalating climate change, environmental pollution, and global crises, plant-based eggs are a viable solution for environmental conservation and health promotion. This study uses an integrated framework combining value-belief-norm (VBN) theory and the Theory of Planned Behavior (TPB) to explore the factors influencing Taiwanese consumers' inclination towards plant-based eggs. Through convenience sampling, 417 questionnaires were issued and 387 valid responses were received, indicating a 92.8% valid response rate. The analysis indicates that consumers' biospheric and altruistic values significantly enhance their awareness of outcomes, which, coupled with their sense of responsibility, strengthens personal norms. From the TPB perspective, perceived behavioral control is identified as a critical driver of the intention to purchase plant-based eggs, with attitudes and subjective norms playing significant roles. Subjective norms positively impact personal norms, thereby influencing consumers' behavioral intentions. The findings confirm the integrated model's theoretical and practical validity, and offer valuable insights for businesses. By developing adept marketing strategies that consider market dynamics, this study enhances the effectiveness and value of marketing efforts by boosting consumers' engagement with plant-based eggs. These insights contribute to advancing environmental sustainability goals.

Eggs - a scoping review for Nordic Nutrition Recommendations 2023

Cardiovascular diseases (CVD), type 2 diabetes (T2D), and cancer are a significant public health burden in the Nordic and Baltic countries. High intake of eggs, mainly due to its high cholesterol content, has been suggested to have adverse health effects. The purpose of this scoping review is to describe the evidence related to the impact of egg intake on health. A literature search identified 38 systematic reviews and meta-analyses on egg consumption in relation to health outcomes published between 2011 and 30 April 2022. Overall, current evidence from systematic reviews of randomized clinical trials indicates that higher egg intake may increase serum total cholesterol concentration and the ratio of low-density lipoprotein to high-density lipoprotein cholesterol, but with substantial heterogeneity in the response. However, recent evidence from observational studies does not provide strong support for a detrimental role of moderate egg consumption (up to one egg/day) on the risk of CVD, especially in the European studies. The overall evidence from observational studies indicates that egg consumption is not associated with increased risk of mortality or T2D in European study populations. There is also little support for a role of egg consumption in cancer development, although a weak association with higher risk of certain cancers has been found in some studies, mainly case-control studies. Again, no associations with cancer risk have been observed in European studies. Systematic reviews and meta-analyses of egg consumption in relation to other health-related outcomes are scarce. There are also limited data available on the associations between the consumption of more than one egg/day and risk of diseases. Based on the available evidence, one egg/day is unlikely to adversely affect overall disease risk.

A Narrative Review on Strategies for the Reversion of Prediabetes to Normoglycemia: Food Pyramid, Physical Activity, and Self-Monitoring Innovative Glucose Devices

In 2019, "Nutrition Therapy for Adults with Diabetes or Prediabetes: A Consensus Report" was published. This consensus report, however, did not provide an easy way to illustrate to subjects with prediabetes (SwPs) how to follow a correct dietary approach. The purpose of this review is to evaluate current evidence on optimum dietary treatment of SwPs and to provide a food pyramid for this population. The pyramid built shows that everyday consumption should consist of: whole-grain bread or potatoes eaten with their skins (for fiber and magnesium) and low glycemic index carbohydrates (GI < 55%) (three portions); fruit and vegetables (5 portions), in particular, green leafy vegetables (for fiber, magnesium, and polyphenols); EVO oil (almost 8 g); nuts (30 g, in particular, pistachios and almonds); three portions of dairy products (milk/yogurt: 300-400 g/day); mineral water (almost 1, 5 L/day for calcium intake); one glass of wine (125 mL); and three cups of coffee. Weekly portions should include fish (four portions), white meat (two portions), protein plant-based food (four portions), eggs (egg portions), and red/processed meats (once/week). At the top of the pyramid, there are two pennants: a green one means that SwPs need some personalized supplementation (if daily requirements cannot be satisfied through diet, vitamin D, omega-3, and vitamin B supplements), and a red one means there are some foods and factors that are banned (simple sugar, refined carbohydrates, and a sedentary lifestyle). Three to four times a week of aerobic and resistance exercises must be performed for 30-40 min. Finally, self-monitoring innovative salivary glucose devices could contribute to the reversion of prediabetes to normoglycemia.

Eggs: Healthy or Risky? A Review of Evidence from High Quality Studies on Hen's Eggs

Hen's eggs (from Gallus gallus domesticus) provide choline, folate, vitamin D, iodine, B vitamins and high-quality protein and are no longer viewed by national bodies as a risk factor for hypercholesterolaemia and cardiovascular disease (CVD). Yet, questions remain about the benefits and risks of eating eggs regularly. This review evaluates recent high-quality evidence from randomised controlled trials (RCT) and meta-analyses of observational studies and considers new areas of interest, such as weight management, protein metabolism, allergy risk and sustainability. In several RCT, eggs increased muscle protein synthesis and lowered fat mass, which could support optimal body composition. Eggs within a meal improved satiety, which could translate into lower energy intakes, although more RCT are needed. In observational studies, higher egg consumption was associated with a null effect or a modest reduced risk of CVD. For type 2 diabetes (T2D) incidence and risk of CVD in people with T2D, there were inconsistencies between observational and RCT data, with the former noting positive associations and the latter seeing no effect of higher egg intake on markers of T2D and CVD. Sustainability metrics suggest that eggs have the lowest planetary impact amongst animal proteins. To lower allergy risk, earlier introduction of eggs into weaning diets is warranted. In conclusion, the balance of evidence points to eggs being a nutritious food suggesting there are broad health benefits from including eggs in the diet at intakes higher than that currently consumed by European populations.

Choline and butyrate beneficially modulate the gut microbiome without affecting atherosclerosis in APOE*3-Leiden.CETP mice

BACKGROUND AND AIMS

Choline has been shown to exert atherogenic effects in Apoe^-/- and Ldlr^-/- mice, related to its conversion by gut bacteria into trimethylamine (TMA) that is converted by the liver into the proinflammatory metabolite trimethylamine-N-oxide (TMAO). Since butyrate beneficially modulates the gut microbiota and has anti-inflammatory and antiatherogenic properties, the aim of the present study was to investigate whether butyrate can alleviate choline-induced atherosclerosis. To this end, we used APOE*3-Leiden.CETP mice, a well-established atherosclerosis-prone model with human-like lipoprotein metabolism.

METHODS

Female APOE*3-Leiden.CETP mice were fed an atherogenic diet alone or supplemented with choline, butyrate or their combination for 16 weeks.

RESULTS

Interestingly, choline protected against fat mass gain, increased the abundance of anti-inflammatory gut microbes, and increased the expression of gut microbial genes involved in TMA and TMAO degradation. Butyrate similarly attenuated fat mass gain and beneficially modulated the gut microbiome, as shown by increased abundance of anti-inflammatory and short chain fatty acid-producing microbes, and inhibited expression of gut microbial genes involved in lipopolysaccharide synthesis. Both choline and butyrate upregulated hepatic expression of flavin-containing monooxygenases, and their combination resulted in highest circulating TMAO levels. Nonetheless, choline, butyrate and their combination did not influence atherosclerosis development, and TMAO levels were not associated with atherosclerotic lesion size.

CONCLUSIONS

While choline and butyrate have been reported to oppositely modulate atherosclerosis development in Apoe^-/- and Ldlr^-/- mice as related to changes in the gut microbiota, both dietary constituents did not affect atherosclerosis development while beneficially modulating the gut microbiome in APOE*3-Leiden.CETP mice.

The association of egg consumption with blood pressure levels and glycated hemoglobin in Spanish adults according to body mass index

The objective of this study was to evaluate the association of egg consumption with blood pressure (BP) and glycated hemoglobin (HbA1c). In addition, it was assessed whether this association changes according to body weight status. This cross-sectional study is based on multicenter data from Spanish adult participants in the EVIDENT II trial. Egg consumption was assessed with a Food Frequency Questionnaire, and data on BP and HbA1c were collected using standardized procedures. Linear regression and ANCOVA models adjusted for the main confounders were performed. The analyses were stratified by body weight status. A total of 668 participants were analyzed (mean age 52.4 ± 11.8 years, 62.3% women). Compared with lower consumption, higher egg consumption was associated with lower systolic (ß =  - 6.15 ± 1.74; p-for-trend = 0.017), diastolic (ß =  - 4.41 ± 1.03; p-for-trend = 0.002), and mean arterial pressure (ß =  - 4.99 ± 1.17; p-for-trend = 0.003) and with lower HbA1c (ß =  - 0.19 ± 0.06; p-for-trend = 0.019) levels. These associations lost statistical significance in the adjusted analyses. The results did not vary by body weight status. In conclusion, consumption of up to 1 egg per day is not associated with BP or HbA1c, even in overweight or obese individuals. Our findings suggested that this frequency of egg consumption is safe as part of a healthy diet and lifestyle for cardiometabolic risk.

Specific Dietary Protein Sources Are Associated with Cardiometabolic Risk Factors in the Boston Puerto Rican Health Study

BACKGROUND

Puerto Rican adults residing in the US mainland experience a high prevalence of metabolic syndrome (MetS). A diet containing healthy protein-rich sources may help control risk factors for MetS.

OBJECTIVE

This study aimed to evaluate 2-year longitudinal associations between intake of various protein-rich foods and changes in the six MetS components.

DESIGN

This is a secondary analysis of a longitudinal cohort study using data from the baseline (2004-2007) and 2-year follow-up visits (2006-2011) in the Boston Puerto Rican Health Study.

PARTICIPANTS/SETTING

Participants were self-identified Puerto Ricans, aged 45 to 75 years, residing in Boston, Massachusetts, or the surrounding area (n = 1,126).

MAIN OUTCOME MEASURES

MetS components were fasting glucose, high-density lipoprotein (HDL) cholesterol, triglycerides, systolic and diastolic blood pressures, and waist circumference.

STATISTICAL ANALYSIS

Baseline intake of foods reported in a semiquantitative food frequency questionnaire were expressed as servings/day, and protein-rich foods were categorized as unprocessed white meat, unprocessed red meat, processed meat, milk and yogurt, cheese, fish and seafood, beans, nuts, and eggs. Associations between each continuous protein food group and continuous 2-year change in MetS components were assessed using linear mixed models adjusted for socioeconomic and behavioral factors, and other dietary sources.

RESULTS

The top contributors to total protein intake were unprocessed red meat (13.3%) and unprocessed poultry (13.0%), and the lowest were eggs (2.92%) and nuts (0.91%). Higher intake of processed meats was associated with an increase in waist circumference over 2 years (β = 1.28; standard error [SE] = 0.63), whereas higher intake of fish and seafood was associated with a decrease in waist circumference (β = -3.47; SE = 1.39). Intake of unprocessed poultry was associated with a decrease in triglycerides (β = -24.5; SE = 9.13). No other significant associations were observed between protein sources and 2-year changes in MetS components.

CONCLUSIONS

Consuming less processed meat and more fish and seafood and unprocessed poultry was associated with decreases in waist circumference and triglycerides among US mainland Puerto Ricans. Other dietary protein sources were not related to cardiometabolic health.

Egg Consumption in the Context of Plant-Based Diets and Cardiometabolic Risk Factors in Adults at Risk of Type 2 Diabetes

BACKGROUND

Plant-based diets (PBDs) are typically recommended to those at risk of type 2 diabetes mellitus (T2DM).

OBJECTIVES

We examined how including eggs, compared with excluding them from PBDs, affected cardiometabolic risk factors in adults at risk of T2DM.

METHODS

This was a randomized, controlled, single-blind, crossover trial of 35 adults (mean age: 60.7 y; 25 women, 10 men) at risk of T2DM assigned to 1 of 2 sequence permutations of 2 dietary treatments (plant-based plus eggs, and exclusively plant-based), with a 4-wk washout period. A dietitian counseled participants to exclude or include 2 eggs daily in the context of PBDs for a 6-wk interval. Our primary outcome measure was endothelial function (EF) measured as flow-mediated dilatation. Secondary outcome measures included lipid profile, blood pressure, insulin sensitivity, anthropometry, and dietary intake. Data were analyzed using generalized linear models.

RESULTS

Compared with egg exclusion, egg inclusion in the context of PBDs did not adversely affect EF (-1.7% ± 6.5% compared with -1.8% ± 7.5%; P = 0.9805). Likewise, egg inclusion, compared with egg exclusion, did not adversely affect (P = 0.1096-0.9781) lipid profile, blood pressure, insulin sensitivity, or anthropometry. Egg inclusion, compared with egg exclusion, improved reported intakes of selenium (23.1 ± 30.3 μg/d compared with 2.3 ± 34.9 μg/d; P = 0.0124) and choline (172.0 ± 96.0 mg/d compared with -3.4 ± 68.1 mg/d; P < 0.0001).

CONCLUSIONS

Consuming 2 eggs daily in the context of PBDs does not adversely affect cardiometabolic risk factors among adults at risk of T2DM. Eggs could be used as an adjuvant to enhance PBDs that are typically recommended for those at risk of T2DM.This trial was registered at clinicaltrials.gov as NCT04316429.

Egg consumption and health effects: A narrative review

This study was planned and conducted to investigate the effects of egg consumption on metabolic syndrome components and potential mechanisms of action on humans. Egg, an important source of animal protein, is defined as a functional food containing various bioactive compounds that can affect the proinflammatory and anti-inflammatory pathways. As a matter of fact, the egg can show immunomodulatory, anti-inflammatory, antioxidant, anticancer, or antihypertensive effects with its bioactive components. It is claimed that egg consumption may protect individuals against metabolic syndrome by increasing HDL-C levels and reducing inflammation. The increase in egg consumption creates the perception that it may lead to cardiovascular diseases due to its cholesterol content. However, there is insufficient evidence as to whether dietary cholesterol-lowers LDL-C. The possible potential mechanisms of egg impact on human health, MEDLINE, Embase, the Cochrane Central, www.ClinicalTrials.gov, PubMed, Science Direct, Google Scholar, and selected websites including) and databases were examined in this regard. With a view to delving into the rather mysterious relationship between egg cholesterol and blood cholesterol, it is necessary to understand the absorption of cholesterol from the egg and to know the functioning of the intestinal microbiota. Studies conducted to date have generally yielded inconsistent results regarding egg consumption and risks of CVD, diabetes, and metabolic syndrome.

Nutritional Viewpoints on Eggs and Cholesterol

Although most current epidemiologic studies indicate no significant association between consuming one egg daily and blood cholesterol levels and cardiovascular risk, arguments still persist with a positive association. Since the diet is one of the most influential factors for this association, we illustrate characteristic features in Japanese people whose dietary pattern is distinct from that, for example, the US (United States) population. Available epidemiologic studies in healthy Japanese people show no association between consumption of one egg daily and blood cholesterol level, consistent with those observed in the US population. However, when consumption of major nutrients and food sources of cholesterol are compared to the US population, Japanese people may have an extra-reserve against the influence of eggs on cardiovascular risk markers, despite consuming relatively more eggs. Further discussion on the influence of nutrients contained in the egg and dietary pattern, including interaction with gut microbes, is necessary. In addition, special consideration at the personalized level is needed for judgment regarding dietary cholesterol not only for hypercholesterolemic patients but for hyper-responsive healthy persons. Although randomized controlled trials with long-term follow-up are required to evaluate the association between consumption of eggs and human health, available information, at least from the nutritional viewpoint, suggests that egg is a healthy and cost-efficient food worldwide.

Egg consumption and risk of type 2 diabetes: findings from 3 large US cohort studies of men and women and a systematic review and meta-analysis of prospective cohort studies

BACKGROUND

Whether egg consumption is associated with the risk of type 2 diabetes (T2D) remains unsettled.

OBJECTIVES

We evaluated the association between egg consumption and T2D risk in 3 large US prospective cohorts, and performed a systematic review and meta-analysis of prospective cohort studies.

METHODS

We followed 82,750 women from the Nurses' Health Study (NHS; 1980-2012), 89,636 women from the NHS II (1991-2017), and 41,412 men from the Health Professionals Follow-up Study (HPFS; 1986-2016) who were free of T2D, cardiovascular disease, and cancer at baseline. Egg consumption was assessed every 2-4 y using a validated FFQ. We used Cox proportional hazard models to estimate HRs and 95% CIs.

RESULTS

During a total of 5,529,959 person-years of follow-up, we documented 20,514 incident cases of T2D in the NHS, NHS II, and HPFS. In the pooled multivariable model adjusted for updated BMI, lifestyle, and dietary confounders, a 1-egg/d increase was associated with a 14% (95% CI: 7%, 20%) higher T2D risk. In random-effects meta-analysis of 16 prospective cohort studies (589,559 participants; 41,248 incident T2D cases), for each 1 egg/d, the pooled RR of T2D was 1.07 (95% CI: 0.99, 1.15; I2 = 69.8%). There were, however, significant differences by geographic region (P for interaction = 0.01). Each 1 egg/d was associated with higher T2D risk among US studies (RR: 1.18; 95% CI: 1.10, 1.27; I2 = 51.3%), but not among European (RR: 0.99; 95% CI: 0.85, 1.15; I2 = 73.5%) or Asian (RR: 0.82; 95% CI: 0.62, 1.09; I2 = 59.1%) studies.

CONCLUSIONS

Results from the updated meta-analysis show no overall association between moderate egg consumption and risk of T2D. Whether the heterogeneity of the associations among US, European, and Asian cohorts reflects differences in egg consumption habits warrants further investigation.This systematic review was registered at www.crd.york.ac.uk/prospero as CRD42019127860.

Egg consumption and cardiovascular risk: a dose-response meta-analysis of prospective cohort studies

Purpose

Cardiovascular disease (CVD) is a leading cause of mortality globally and is strongly influenced by dietary risk factors. The aim was to assess the association between egg consumption and risk of CVD risk/mortality, including coronary heart disease (CHD), stroke, and heart failure.

Methods

MEDLINE, Embase, and Web of Science databases were searched through April 2020 for prospective studies. Two independent reviewers screened and extracted the data through standardized methods. Size effects were calculated as summary relative risks (SRRs) in a dose–response fashion through random-effects meta-analyses.

Results

Thirty-nine studies including nearly 2 million individuals and 85,053 CHD, 25,103 stroke, 7536 heart failure, and 147,124 CVD cases were included. The summary analysis including 17 datasets from 14 studies conducted on CVD (incidence and/or mortality) showed that intake of up to six eggs per week is inversely associated with CVD events, when compared to no consumption [for four eggs per week, SRR = 0.95 (95% CI: 0.90; 1.00)]; a decreased risk of CVD incidence was observed for consumption of up to one egg per day [SRR = 0.94 (95% CI: 0.89; 0.99)]. The summary analysis for CHD incidence/mortality including 24 datasets from 16 studies showed a decreased risk up to two eggs per week [(SRR = 0.96 (95% CI: 0.91; 1.00)]. No associations were retrieved with risk of stroke. The summary analysis for heart failure risk including six datasets from four studies showed that intake of one egg per day was associated with increased risk raising for higher intakes compared to no consumption [for 1 egg per day, SRR = 1.15 (95% CI:1.02; 1.30)]. After considering GRADE criteria for strength of the evidence, it was rated low for all outcomes but stroke, for which it was moderate (yet referring to no risk).

Conclusion

There is no conclusive evidence on the role of egg in CVD risk, despite the fact that higher quality studies are warranted to obtain stronger evidence for a possible protection of CVD associated with moderate weekly egg consumption compared to no intake; equally, future studies may strengthen the evidence for increased heart failure risk associated with high regular egg consumption.

Electronic supplementary material

The online version of this article (10.1007/s00394-020-02345-7) contains supplementary material, which is available to authorized users.

Intake of Animal Source Foods in Relation to Risk of Metabolic Syndrome

Metabolic syndrome (MetS) is a prevalent disorder associated with diabetes and cardiovascular diseases. Lifestyle and occupation can increase the risk of developing MetS. Since dietary pattern is a major component of lifestyle, this study aimed to determine the relationship between consumption of animal source foods (ASFs) and MetS among food suppliers. This cross-sectional study was conducted on 112 male food suppliers. We measured anthropometric indices, body composition, and blood pressure of the participants. Blood biochemistry was determined using 5 mL fasting blood samples. MetS was defined based on the guidelines described by the International Diabetes Federation (IDF). ASF intake, including dairy products, eggs, red meat, poultry, and fish, was assessed using food frequency questionnaires. Overall, 46.4% of participants had MetS. Participants who consumed dairy 3∼5 times/d and more than 5 times/d had lower risk of MetS [odds ratios (OR): 0.18 (confidence interval (CI) 95%: 0.05∼0.62) and OR: 0.20 (CI 95%: 0.06∼0.67), respectively] compared with participants in the lowest tertile. The risk of hypertension was significantly decreased in participants who consumed dairy products >5 times/d [OR: 0.22 (CI 95%: 0.07∼0.67)]. Other ASFs were not associated against the risk of MetS in crude and adjusted models. Our findings indicated that adhering to dairy products can decrease the risk of MetS. Higher adherence to dairy products was also protective against hypertension in these participants.

Effects of substituting eggs for high-carbohydrate breakfast foods on the cardiometabolic risk-factor profile in adults at risk for type 2 diabetes mellitus

Objectives

To assess effects of egg-based versus non-egg, higher-carbohydrate (CHO) breakfast meals on cardiometabolic health markers in overweight or obese adults with prediabetes and/or metabolic syndrome.

Methods

This randomized, crossover study included two 4-week dietary interventions, separated by a ≥4-week washout. Subjects incorporated into their habitual diets breakfast meals containing either 2 eggs/day for 6 days/week (Egg condition), or energy-matched, non-egg, higher-CHO-based foods (Non-Egg condition). Dietary intakes, insulin sensitivity, and other CHO metabolism indices, lipid biomarkers, high-sensitivity C-reactive protein, and blood pressures were measured.

Results

Thirty men and women with mean age 54.1 ± 1.9 years and body mass index 31.9 ± 0.7 kg/m² provided data. Neither diet condition significantly altered insulin sensitivity indices, but the homeostasis model assessment for insulin resistance was significantly (p = 0.028) higher after the Non-Egg vs. the Egg condition. Low-density lipoprotein cholesterol (LDL-C) was decreased from baseline (119 mg/dL) by 2.9 and 6.0% with Egg and Non-Egg breakfasts, respectively (p = 0.023). Systolic blood pressure was reduced from baseline (127 mm Hg) by 2.7 and 0.0% with Egg and Non-Egg, respectively (p = 0.018). Diet records indicated 149 kcal/day higher (p = 0.008) energy intake from non-study foods during the Egg condition; however, weight change from baseline did not differ between conditions.

Conclusion

Compared with the baseline diet, consumption of 12 eggs/week for 4 weeks at breakfast was associated with less reduction in LDL-C, and more lowering of systolic blood pressure, than observed with non-egg-based, energy-matched, control foods higher in CHO.

Egg consumption and risk of cardiovascular disease: three large prospective US cohort studies, systematic review, and updated meta-analysis

OBJECTIVE

To evaluate the association between egg intake and cardiovascular disease risk among women and men in the United States, and to conduct a meta-analysis of prospective cohort studies.

DESIGN

Prospective cohort study, and a systematic review and meta-analysis of prospective cohort studies.

SETTING

Nurses' Health Study (NHS, 1980-2012), NHS II (1991-2013), Health Professionals' Follow-Up Study (HPFS, 1986-2012).

PARTICIPANTS

Cohort analyses included 83 349 women from NHS, 90 214 women from NHS II, and 42 055 men from HPFS who were free of cardiovascular disease, type 2 diabetes, and cancer at baseline.

MAIN OUTCOME MEASURES

Incident cardiovascular disease, which included non-fatal myocardial infarction, fatal coronary heart disease, and stroke.

RESULTS

Over up to 32 years of follow-up (>5.54 million person years), 14 806 participants with incident cardiovascular disease were identified in the three cohorts. Participants with a higher egg intake had a higher body mass index, were less likely to be treated with statins, and consumed more red meats. Most people consumed between one and less than five eggs per week. In the pooled multivariable analysis, consumption of at least one egg per day was not associated with incident cardiovascular disease risk after adjustment for updated lifestyle and dietary factors associated with egg intake (hazard ratio for at least one egg per day v less than one egg per month 0.93, 95% confidence interval 0.82 to 1.05). In the updated meta-analysis of prospective cohort studies (33 risk estimates, 1 720 108 participants, 139 195 cardiovascular disease events), an increase of one egg per day was not associated with cardiovascular disease risk (pooled relative risk 0.98, 95% confidence interval 0.93 to 1.03, I²=62.3%). Results were similar for coronary heart disease (21 risk estimates, 1 411 261 participants, 59 713 coronary heart disease events; 0.96, 0.91 to 1.03, I²=38.2%), and stroke (22 risk estimates, 1 059 315 participants, 53 617 stroke events; 0.99, 0.91 to 1.07, I²=71.5%). In analyses stratified by geographical location (P for interaction=0.07), no association was found between egg consumption and cardiovascular disease risk among US cohorts (1.01, 0.96 to 1.06, I²=30.8%) or European cohorts (1.05, 0.92 to 1.19, I²=64.7%), but an inverse association was seen in Asian cohorts (0.92, 0.85 to 0.99, I²=44.8%).

CONCLUSIONS

Results from the three cohorts and from the updated meta-analysis show that moderate egg consumption (up to one egg per day) is not associated with cardiovascular disease risk overall, and is associated with potentially lower cardiovascular disease risk in Asian populations.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019129650.

Dietary Choline or Trimethylamine N-oxide Supplementation Does Not Influence Atherosclerosis Development in Ldlr-/- and Apoe-/- Male Mice

BACKGROUND

Choline, an essential nutrient, is required for cell membranes, lipoprotein secretion, and methyl-group metabolism. Recently, it has been proposed that excess dietary choline consumption is metabolized to trimethylamine (TMA) by the gut microbiota; TMA is then oxidized to trimethylamine N-oxide (TMAO) in the liver. Epidemiological studies have clearly shown a positive correlation between plasma TMAO concentrations and cardiovascular events. Furthermore, some studies have shown an association between excess dietary choline, plasma TMAO concentrations, and atherosclerotic lesion size in apoE knockout (Apoe-/-) mice.

OBJECTIVE

The aim of this study was to further investigate the relation between dietary choline and atherosclerosis in 2 atherogenic mouse models, the LDL receptor knockout (Ldlr-/-) and Apoe-/- mice.

METHODS

Six feeding trials were performed in Ldlr-/- (40% high-fat diet) and Apoe-/- (unpurified diet) male mice, aged 8-10 wk. Mice randomly received control diet (0.1% choline), or choline- (1% choline), betaine- (0.1% choline and 0.9% betaine), or TMAO- (0.1% choline and 0.12% or 0.2% TMAO) supplemented diet for ≤28 wk. After the dietary intervention, the animals were killed and tissues and blood collected. Aortic atherosclerotic plaque area, plasma lipids, and choline metabolites were quantified.

RESULTS

In Ldlr-/- mice, dietary supplementation for 8 wk with choline or TMAO increased plasma TMAO concentrations by 1.6- and 4-fold, respectively. After 16 wk, there was a 2-fold increase in plasma TMAO after dietary TMAO supplementation. In Apoe-/- mice, dietary supplementation with choline, betaine, or TMAO for 12 wk did not increase plasma TMAO concentrations. However, choline and TMAO supplementation for 28 wk significantly increased plasma TMAO concentrations by 1.8- and 1.5-fold, respectively. Contrary to predictions, atherosclerotic lesion size was not altered by any of the dietary interventions, irrespective of mouse model.

CONCLUSIONS

In our study, high intakes of dietary choline or TMAO supplementation did not influence atherosclerosis development in Ldlr-/- or Apoe-/- male mice.

Association of circulating cystatin C levels with type 2 diabetes mellitus: a systematic review and meta-analysis

INTRODUCTION

This study aimed to systemically summarize the present literature about circulating cystatin C (Cys C) levels in type 2 diabetes mellitus (T2DM) and provide a more precise evaluation of Cys C levels in T2DM.

MATERIAL AND METHODS

Relevant studies about Cys C concentrations in T2DM were searched in PubMed, EMBASE and the Cochrane Library database (up to Oct 31 2018). We computed the pooled standard mean difference (SMD) with its 95% confidence interval (CI) of Cys C levels through a random-effect model. The Q test and the I² statistic were used to assess and quantify between-study heterogeneity; publication bias was evaluated through a funnel plot and Egger's linear regression test.

RESULTS

After the literature search and screening process, 14 studies with 723 T2DM patients and 473 healthy controls were finally included in the meta-analysis. The results showed that T2DM patients had significantly higher Cys C levels compared to healthy controls (SMD = 1.39, 95% CI: 0.92-1.86, p < 0.001). Publication bias was not detected based on the symmetrical shape of the funnel plot and the results of Egger's test (p = 0.452). Subgroup analyses suggested that variables of human race, age, gender, study sample size and disease duration have a relationship with Cys C level in T2DM patients.

CONCLUSIONS

Overall, our study suggests that patients with T2DM have an elevated circulating Cys C level compared to healthy controls, and it is associated with race, age, gender, study sample size and disease duration. Further investigations are still needed to explore the causal relationship of aberrant Cys C concentrations in T2DM.

The effect of egg consumption on cardiometabolic health outcomes: an umbrella review

Objective:

This umbrella review provides an overview of the consistency and gaps in the evidence base on eggs and cardiometabolic health.

Design:

PubMed, Web of Science, Cochrane Library, the Nutrition Evidence Systematic Review and Agency for Healthcare Research and Quality databases were screened for evidence-based reviews in English that assessed human studies on egg consumption and cardiometabolic outcomes.

Results:

Seven systematic reviews and fifteen meta-analyses were identified, with eighteen of these published since 2015. Overall, the systematic reviews were of low quality, while meta-analyses were of moderate- to high-quality. No association of increased egg intake and risks of heart disease or stroke in the general population were found in the meta-analyses. Increased risk of heart failure was noted in two meta-analyses that analysed the same three cohort studies. Five recent meta-analyses reported no increased risk of type 2 diabetes mellitus (T2DM) in the general population, although increased risk in US-based populations only has been reported. Older (<2013) meta-analyses reported increased risks of cardiovascular disease (CVD) or heart disease in T2DM populations, and no recent evidence-based reviews were identified. Finally, only one meta-analysis reported intervention studies specifically on eggs and biomarkers (i.e. lipids), and the results contradicted those from observation studies.

Conclusions:

Recent evidence-based reviews conclude that increased egg consumption is not associated with CVD risk in the general population. More research is needed on the positive associations between egg consumption and heart failure and T2DM risk, as well as CVD risk in diabetics, before firm conclusions can be made.

Dietary cholesterol does not break your heart but kills your liver

It is increasingly accepted that dietary cholesterol has a much lower impact on the progression of cardiovascular disease than previously assumed. However, both animal experiments and human studies seem to support the view that dietary cholesterol may contribute to the transition from benign steatosis to the potentially fatal non-alcoholic steatohepatitis. Cholesterol esters and cholesterol accumulate in the hepatocyte and impair its function. This leads to oxidative stress and endoplasmic reticulum stress triggering the release of pro-inflammatory cytokines and rendering the hepatocyte more susceptible to apoptotic or necrotic cell death. Kupffer cells group around dying hepatocytes and phagocytose the hepatocyte debris and lipids. In addition, they are exposed to lipid peroxidation products released from hepatocytes. Kupffer cells, thus activated, release pro-inflammatory, chemotactic and profibrotic cytokines that promote inflammation and fibrosis. Therefore, dietary cholesterol may be harmful to the liver, in particular when administered in combination with polyunsaturated fatty acids that favor lipid peroxidation.

High Density Lipoprotein from Egg Yolk (EYHDL) Improves Dyslipidemia by Mediating Fatty Acids Metabolism in High Fat Diet-induced Obese Mice

We investigated the effect of high density lipoprotein from egg yolk (EYHDL) on serum, hepatic and fecal lipid and fatty acids (FAs) levels and on gene expression involved in FAs metabolism. Male KM mice were fed either normal diet (ND; n=20), high fat diet (HFD; n=20), or high fat diet containing EYHDL (EYHDL; 0.6 mg/g, every day by oral gavage, n=20) for 100 days. At the end of the experiment, the effects of treatments on biochemical parameters, FAs profiles and involved gene expression were analyzed. Our results revealed that EYHDL markedly suppressed the body weight gain, accumulation of abdominal fat tissues, serum concentrations of LDL-cholesterol (LDL-C) and triglycerides, hepatic triglycerides and cholesterol accumulation, while increased serum concentration of HDL-cholesterol (HDL-C). EYHDL intake also increased total cholesterol (TC) excretions compared with HFD group. Moreover, it alleviated the severity of fatty liver and improved glucose and insulin tolerance compared with HFD. More importantly, EYHDL partially normalized FAs profiles in serum, liver and fecaces and neutralized the HFD-induced upregulation of SREBP-1c, Acaca, Fasn, GPAT and Scd1. In conclusion, our findings indicate that EYHDL may have the potential to improve metabolic disturbances that occur in HFD mice and can be considered as an appropriate dietary recommendation for the treatment of metabolic syndrome (MetS).

Association of eggs with dietary nutrient adequacy and cardiovascular risk factors in US adults

OBJECTIVE

Whole eggs are rich sources of several micronutrients. However, it is not well known how egg consumption contributes to overall nutrient adequacy and how it may relate to CVD risk factors. Therefore, the present study aimed to determine how whole egg consumption contributes to nutrient intakes and to assess its association with CVD risk factors in US adults.

DESIGN

Cross-sectional study.

SETTING

The study was conducted using data from the National Health and Nutrition Examination Survey (NHANES) 2003-2012, a nationally representative survey of the US civilian population.ParticipantsAdults who completed two dietary recalls and provided information on relevant sociodemographic factors were included in the study (n 21 845).

RESULTS

Approximately 73 % of adults were classified as whole egg consumers. Egg consumption was associated with greater intakes of protein, saturated fat, mono- and polyunsaturated fats, Fe, Zn, Ca, Se, choline, and several other vitamins and minerals. Egg consumption was associated with a higher likelihood of meeting or exceeding recommendations for several micronutrients. Egg intake was positively associated with dietary cholesterol consumption, but not with serum total cholesterol (TC) when adjusted for multiple potential confounders. In multiple linear regression analyses, TAG, TAG:HDL-cholesterol and TC:HDL-cholesterol were significantly lower with greater egg consumption. Egg consumption had no significant relationship with LDL-cholesterol or C-reactive protein, but was associated with higher BMI and waist circumference.

CONCLUSIONS

Whole eggs are important dietary contributors of many nutrients and had either beneficial or non-significant associations with most CVD risk biomarkers examined.

Mechanism and Potential of Egg Consumption and Egg Bioactive Components on Type-2 Diabetes

Type-2 diabetes (T2D) is one of the major global health challenges and a substantial economic burden. Egg and egg-derived components have been indicated to possess antioxidant, anti-inflammatory, anti-hypertensive, immunomodulatory, and anti-cancer activities. However, the scientific evidence about the benefits of egg on T2D is debatable. The relationship between egg consumption and the risk of T2D from observational epidemiological studies is not consistent. Interventional clinical studies, however, provide promising evidence that egg consumption ameliorates the risk of T2D. Current research progress also indicates that some egg components and egg-derived peptides might be beneficial in the context of T2D, in terms of insulin secretion and sensitivity, oxidative stress, and inflammation, suggesting possible application on T2D management. The current review summarizes recent clinical investigations related to the influence of egg consumption on T2D risk and in vivo and in vitro studies on the effect and mechanism of egg components and egg-derived peptides on T2D.

Comparison of long-term effects of egg yolk consumption under normal and high fat diet on lipid metabolism and fatty acids profile in mice

This study compared the long-term effects of EY consumption under two diet conditions: normal (ND + EY) and high fat diet (HFD + EY), on lipid metabolism in mice. ND + EY did not increase serum triglycerides, total cholesterol hepatic triglyceride concentrations, adipose tissue accumulation and glucose impairment, not leading to fatty liver. HFD + EY markedly decreased adipose tissue accumulation, the triglyceride and total cholesterol, and improved serum HDL-C and blood glucose impairment compared with HFD. PLS-DA analyzes showed both ND + EY and HFD + EY could decrease serum C18:1 and MUFA. HFD + EY could further decrease hepatic C18:2 and PUFA and increase C18:1 and MUFA excretion, which were associated with lower expression of Elovl6 and higher expression of Scd1 in liver. These results suggest that HFD + EY significantly improved dyslipidemia caused by HFD through modifying lipid metabolism, and ND + EY did not adversely affect the biomarkers associated with dyslipidemia risk, but showed less obvious regulation of lipid metabolism than HFD + EY.

Longitudinal association between egg consumption and the risk of cardiovascular disease: interaction with type 2 diabetes mellitus

Background/objectives

It remains unclear if high egg consumption has beneficial or adverse effects on cardiometabolic health. The present study prospectively evaluated the longitudinal association between egg-consumption levels and incident cardiovascular disease (CVD) among Korean adults.

Subjects/methods

We conducted a prospective cohort study of 9248 Korean adults aged 40–69 years without CVD or cancer at the baseline from the Korean Genome and Epidemiology Study, Ansung–Ansan cohort, South Korea. The egg intake of the participants was estimated using a validated semiquantitative food frequency questionnaire at the baseline and the second follow-up examination and categorized into quartiles. CVD cases were identified using biennial questionnaires and confirmed through repeated in-depth personal interviews. Hazard ratios (HR) and 95% confidence interval (CI) were analyzed using Cox proportional hazard regression.

Results

During the average follow-up of 7.3 years, 570 cases of CVD were newly diagnosed. After adjusting for multiple confounding variables, egg-intake levels were not associated with CVD incidence (HR: 1.14, 95% CI: 0.87–1.49, P for trend: 0.7). However, the association was modified by type 2 diabetes mellitus (T2DM) status. Egg consumption was significantly associated with an increased risk for incident CVD among participants with T2DM; individuals with the highest egg intake (4.2 ± 0.04 eggs/week) had a 2.8 times higher incidence of CVD (HR: 2.81, 95% CI: 1.25–6.30, P for trend: 0.02) than those with the lowest egg intake (0.1 ± 0.02 eggs/week). However, no association was observed among individuals without T2DM (HR: 1.03, 95% CI: 0.77–1.38, P for trend: 0.8).

Conclusions

Higher egg consumption may increase the risk for CVD in Korean patients with T2DM. Our findings provide a basis for the development of an optimal dietary cholesterol intake guideline for the Korean population.

Nutrition and Cardiovascular Disease-an Update

PURPOSE OF REVIEW

This review summarizes recent developments in nutrition and cardiovascular disease (CVD) prevention.

RECENT FINDINGS

Contemporary dietary guidance recommends healthy dietary patterns with emphasis on food-based recommendations because the totality of the diet (i.e., the combinations and quantities of foods and nutrients consumed) is an important determinant of health. In many guidelines, recommendations are still made for saturated fat, added sugar, sodium, and dietary cholesterol because these are over-consumed by many people and are related to chronic disease development. Epidemiological research illustrates the importance of considering the total diet and the interrelatedness of nutrients in a dietary pattern. Traditionally, epidemiological research focused on individual nutrients in isolation, which can result in erroneous conclusions. An example of this, which has led to substantial controversy, is the evidence from studies evaluating the association between saturated fat and CVD without considering the replacement nutrient. Another controversial topic is the relationship between dietary cholesterol and CVD, which is confounded by saturated fat intake. Finally, the totality of evidence shows that high sodium intake is associated with greater CVD risk; however, some epidemiological research has suggested that a low-sodium intake is detrimental, which has caused some controversy. Overall, this reductionist approach has led to a debate about recommendations for saturated fat, cholesterol, and sodium. However, if approaches that accounted for the interrelatedness of nutrients had been taken, it is likely that there would be less controversy about these nutrients. To encourage dietary pattern-based approaches and consideration of total intake, dietary guidelines should emphasize food-based recommendations that meet nutrient targets. Thus, nutrient targets should underpin food-based dietary guidelines, and recommended dietary patterns should comply with nutrient-based targets. The evidence reviewed shows that it is imperative to consider total dietary patterns for CVD prevention. Dietary guidance should be aligned with nutrient targets and recommendations should be food and dietary pattern based.