Dietary cholesterol and egg intake in relation to incident cardiovascular disease and all-cause and cause-specific mortality in postmenopausal women

Dietary cholesterol intake is not associated with the development of chronic kidney disease: Results from two Korean cohort studies

BACKGROUND AND AIMS

Although dyslipidemia is a major risk factor for chronic kidney disease (CKD), the relationship between dietary cholesterol and CKD remains unknown. We investigated the association between cholesterol intake and CKD risk.

METHODS AND RESULTS

The Korea National Health and Nutrition Examination Survey (KNHANES) 2019-2021 (n = 13,769) and the Korean Genome and Epidemiology Study (KoGES) (n = 9225) data were used for this study. Cholesterol intake was assessed using a 24-h recall food frequency questionnaire, and participants were categorized into three groups (T1, T2, and T3) based on cholesterol intake. Primary outcomes were prevalence and incidence of CKD. Higher cholesterol intake was modestly associated with increased serum levels of total, low-density lipoprotein, and high-density lipoprotein cholesterol in the KNHANES. However, we found no significant association between cholesterol intake and CKD prevalence in the KNHANES, regardless of a history of hypercholesterolemia. In the KoGES, during a median follow-up of 11.4 years, cholesterol intake was not associated with incident CKD in participants without hypercholesterolemia (hazard ratio [HR] per 10 mg increase, 1.00; 95 % confidence interval [CI], 0.99-1.01) and in those with hypercholesterolemia (HR, 1.01; 95 % CI, 0.98-1.04). Egg consumption also showed no significant association with the risk of incident CKD. Additionally, cholesterol intake had no significant interaction on the relationships between serum cholesterol levels and incident CKD.

CONCLUSION

Although cholesterol intake was associated with increased serum cholesterol levels, it was not associated with CKD prevalence and incidence. Our findings suggest that reducing cholesterol intake alone may not be sufficient to prevent CKD.

Associations between Cholesterol Intake, Food Sources and Cardiovascular Disease in Chinese Residents

Cholesterol is a nutrient commonly found in the human diet. The relationship between dietary cholesterol, its sources, and cardiovascular disease (CVD) is still a topic of debate. This study aimed to investigate the association between dietary cholesterol, its sources, and cardiovascular events in a Chinese population. The present study analyzed data from the China Health and Nutrition Survey (CHNS) cohort between 1991 and 2015. This study analyzed data from 3903 participants who were 40 years of age or older at baseline and had no history of cardiovascular disease, diabetes, or hypertension. During a median follow-up of 14 years, 503 cardiovascular disease events were identified through follow-up questionnaires administered every 2-3 years. The events included fatal and nonfatal coronary heart disease, stroke, heart failure, and other cardiovascular disease deaths. Cox regression was used to estimate risk ratios (HR) for CVD events after adjusting for demographic, socioeconomic, and behavioral factors. It was discovered that sources of dietary cholesterol varied among different subgroups of the population. The top three sources of cholesterol among all participants were eggs, red meat, and seafood, accounting for 57.4%, 28.2%, and 9.0% of total daily cholesterol intake, respectively. The present study found that there was a significant association between total dietary cholesterol intake, and the risk of developing cardiovascular disease (adjusted HR [95% CI]: total cholesterol (highest and lowest quartiles compared) 1.57 [1.17-2.11]). Cholesterol from poultry, seafood, and eggs was also significantly associated with a reduced risk of CVD (adjusted HR [95% CI]: poultry 0.18 [0.04-0.82], seafood 0.11 [0.02-0.54], and eggs 0.16 [0.03-0.73]). After adjusting for daily caloric intake, daily fat intake, and daily saturated fat intake, the previously observed association between red meat cholesterol and cardiovascular events (unadjusted HR [95% CI]: 0.44 [0.35-0.55]) was no longer statistically significant (adjusted HR [95% CI]: 0.21 [0.04-1.01]).

Substitution of animal-based with plant-based foods on cardiometabolic health and all-cause mortality: a systematic review and meta-analysis of prospective studies

BACKGROUND

There is growing evidence that substituting animal-based with plant-based foods is associated with a lower risk of cardiovascular diseases (CVD), type 2 diabetes (T2D), and all-cause mortality. Our aim was to summarize and evaluate the evidence for the substitution of any animal-based foods with plant-based foods on cardiometabolic health and all-cause mortality in a systematic review and meta-analysis.

METHODS

We systematically searched MEDLINE, Embase, and Web of Science to March 2023 for prospective studies investigating the substitution of animal-based with plant-based foods on CVD, T2D, and all-cause mortality. We calculated summary hazard ratios (SHRs) and 95% confidence intervals (95% CI) using random-effects meta-analyses. We assessed the certainty of evidence (CoE) using the GRADE approach.

RESULTS

In total, 37 publications based on 24 cohorts were included. There was moderate CoE for a lower risk of CVD when substituting processed meat with nuts [SHR (95% CI): 0.73 (0.59, 0.91), n = 8 cohorts], legumes [0.77 (0.68, 0.87), n = 8], and whole grains [0.64 (0.54, 0.75), n = 7], as well as eggs with nuts [0.83 (0.78, 0.89), n = 8] and butter with olive oil [0.96 (0.95, 0.98), n = 3]. Furthermore, we found moderate CoE for an inverse association with T2D incidence when substituting red meat with whole grains/cereals [0.90 (0.84, 0.96), n = 6] and red meat or processed meat with nuts [0.92 (0.90, 0.94), n = 6 or 0.78 (0.69, 0.88), n = 6], as well as for replacing poultry with whole grains [0.87 (0.83, 0.90), n = 2] and eggs with nuts or whole grains [0.82 (0.79, 0.86), n = 2 or 0.79 (0.76, 0.83), n = 2]. Moreover, replacing red meat for nuts [0.93 (0.91, 0.95), n = 9] and whole grains [0.96 (0.95, 0.98), n = 3], processed meat with nuts [0.79 (0.71, 0.88), n = 9] and legumes [0.91 (0.85, 0.98), n = 9], dairy with nuts [0.94 (0.91, 0.97), n = 3], and eggs with nuts [0.85 (0.82, 0.89), n = 8] and legumes [0.90 (0.89, 0.91), n = 7] was associated with a reduced risk of all-cause mortality.

CONCLUSIONS

Our findings indicate that a shift from animal-based (e.g., red and processed meat, eggs, dairy, poultry, butter) to plant-based (e.g., nuts, legumes, whole grains, olive oil) foods is beneficially associated with cardiometabolic health and all-cause mortality.

The Global Association between Egg Intake and the Incidence and Mortality of Ischemic Heart Disease-An Ecological Study

The relationship between egg consumption and ischemic heart disease (IHD) remains controversial as there is still no clear answer regarding the relationship, with research limited to a few geographical regions. In the current study, we conducted a longitudinal analysis of the association between egg intake and IHD incidence (IHDi) and mortality (IHDd) using 28 years of international data from 1990 to 2018. Egg intake (g/day/capita) by country was obtained from the Global Dietary Database. Age-standard IHDi and IHDd rates per 100,000 subjects in each country were obtained from the 2019 Global Burden of Disease database. The analysis included a total of 142 countries with populations of at least one million, for which all data were available from 1990 to 2018. Eggs are consumed worldwide, and regional differences in consumption are also shown. Utilizing IHDi and IHDd as objective variables and egg intake as an explanatory variable, the analysis was conducted using linear mixed models, which controlled for inter- and intra-country variation from year to year. The results showed a significant negative association between egg intake, and IHDi (-0.253 ± 0.117, p < 0.05) and IHDd (-0.359 ± 0.137, p < 0.05). The analysis was carried out using R 4.0.5. The results suggest that adequate egg intake might suppress IHDi and IHDd on a global scale.

Egg Intake Is Associated with Lower Risks of Impaired Fasting Glucose and High Blood Pressure in Framingham Offspring Study Adults

The association between egg consumption and cardiometabolic risk factors such as high blood pressure (HBP) and impaired fasting glucose (IFG) or type 2 diabetes (T2D) is still under debate. This study examines the association between egg consumption and these outcomes among 2349 30-64 year-old adults in the prospective Framingham Offspring Study. Diet was assessed using three-day dietary records. Potential confounders retained in the final models included age, sex, body mass index, and other dietary factors. The analysis of covariance and Cox proportional hazard's models were used to assess the relevant continuous (i.e., FG, SBP, DBP) and categorical (i.e., T2D, HBP) outcomes. Consuming ≥5 eggs per week was associated with lower mean FG (p = 0.0004) and SBP (p = 0.0284) after four years of follow-up. Higher egg intakes led to lower risks of developing IFG or T2D (HR: 0.72; 95% CI: 0.51-1.03) and high blood pressure (HBP) (HR: 0.68; 0.50-0.93). The beneficial effects of egg consumption were stronger in combination with other healthy dietary patterns. This study found that regular egg consumption as part of a healthy diet had long-term beneficial effects on blood pressure and glucose metabolism and lowered the long-term risks of high blood pressure and diabetes.

Frequency of Egg Intake Associated with Mortality in Chinese Adults: An 8-Year Nationwide Cohort Study

Whether egg consumption plays a beneficial/detrimental role in affecting human health and longevity has been debated for decades. Large-scale cohort evidence from low- and middle-income populations are scarce. In this study, we aimed to assess the association of egg consumption with mortality in Chinese adults. A nationwide cohort of 30,835 participants ages 16-110 years were enrolled from 25 provincial regions in China's mainland. Dietary intake (e.g., egg, meat, vegetable) was assessed by a food-frequency questionnaire. Cox proportional hazards models were used to examine associations between egg consumption and mortality, adjusting for demographic characteristics, dietary factors and health status. Dose-response relationships were investigated using the smoothing function of restricted cubic splines. Several subgroup analyses were performed. A total of 1651 all-cause deaths occurred during a median follow-up of 8.1 years. Egg consumption was associated with lower risks of mortality, with the lowest risk occurring in the group of moderate egg intake (3-6 times/week). Compared with non-consumers, the hazard ratios (95% confidence intervals) for mortality were 0.84 (0.72-0.97) for 3-6 times/week and 0.82 (0.69-0.98) for ≥7 times/week, whereas no significant associations were observed among the lower egg intake group (1-2/week). An approximately inverted J-shaped association was observed in three models, while restricting our analysis in the multivariable model (model 3) did not identify a significant violation for the linear relationship (p for nonlinear = 0.122). There were no statistically significant effect modifications in the subgroup analyses. Egg consumption may be associated with lower risks of mortality in Chinese adults. Our findings found moderate-to-high egg consumption might be beneficial for improving long-term health and longevity.

Association of Egg Consumption with Risk of All-Cause and Cardiovascular Disease Mortality: A Systematic Review and Dose-Response Meta-Analysis of Observational Studies

BACKGROUND

Recent studies have reported conflicting associations between egg consumption and the risk of all-cause or cardiovascular disease (CVD) mortality, including ischemic heart disease (IHD) mortality and stroke mortality. With accumulating evidence, up-to-date evidence about the association should be synthesized.

OBJECTIVES

We aimed to assess the association of the risk of all-cause and CVD mortality with egg consumption.

METHODS

We searched the PubMed, Embase, and Web of Science databases through 3 November, 2021 for observational studies conducted in participants ≥18 y of age and which provided ORs, RRs, or HRs and 95% CIs for ≥3 egg consumption categories or for increased intake of egg addressing the associations of interest. A random-effects model was used to pool the reported risk estimates. Restricted cubic splines were used to examine the dose-response association.

RESULTS

Twenty-four articles with 48 reports (25 for all-cause mortality, 11 for CVD mortality, 6 for IHD mortality, and 6 for stroke mortality) involving 11,890,695 participants were included. Intake of each 1-egg/d increment was associated with increased risk of all-cause mortality (RR: 1.06; 95% CI: 1.02, 1.10; P = 0.008), but the association was restricted to women, Americans, and studies with adjustments for hyperlipidemia. Egg consumption was linearly associated with CVD mortality only in participants >60 y of age, Americans, studies with follow-up duration ≥15 y, and studies with adjustments for hyperlipidemia (P ≤ 0.018). No significant association was found between egg consumption and IHD or stroke mortality (P ≥ 0.080).

CONCLUSIONS

Egg consumption was linearly associated with a modestly increased risk of all-cause mortality and, in older participants, Americans, and studies with longer follow-up or adjustments for hyperlipidemia, CVD mortality. These findings suggest that it may be prudent to avoid high egg consumption.

Association of Dietary Pattern with Cardiovascular Risk Factors among Postmenopausal Women in Taiwan: A Cross-Sectional Study from 2001 to 2015

Unhealthy diet and inappropriate lifestyle contribute to an imbalance in cardiometabolic profiles among postmenopausal women. This research aimed to analyze the association between dietary pattern and changes in cardiovascular risk factors among postmenopausal Taiwanese women using binary logistic regression. This cross-sectional study involved 5689 postmenopausal Taiwanese women aged 45 years and above, and the data were obtained from Mei Jau Health Management Institution database between 2001 and 2015. The cardiovascular risk dietary pattern characterized by high intakes of processed food, rice/flour products, organ meat, and sauce was derived by reduced rank regression. Participants in the highest quartile of the cardiovascular risk dietary pattern were more likely to have high levels of systolic blood pressure (OR = 1.29, 95% CI 1.08-1.53), diastolic blood pressure (OR = 1.28, 95% CI 1.01-1.62), atherogenic index of plasma (OR = 1.26, 95% CI 1.06-1.49), triglycerides (OR = 1.38, 95% CI 1.17-1.62), and fasting blood glucose (Q3: OR = 1.45, 95% CI 1.07-1.97). However, this dietary pattern was not correlated with total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and C-reactive protein. Therefore, adherence to the cardiovascular risk dietary pattern increases the risk of having higher levels of blood pressure, triglycerides, fasting blood glucose in postmenopausal Taiwanese women.

Egg and Dietary Cholesterol Intake and Risk of All-Cause, Cardiovascular, and Cancer Mortality: A Systematic Review and Dose-Response Meta-Analysis of Prospective Cohort Studies

Objective

This systematic review and meta-analysis of prospective cohort studies examined the associations between egg and dietary cholesterol intake and the risk of mortality from all causes, including cardiovascular disease (CVD) and cancer.

Methods

We searched PubMed, Scopus, ISI Web of Knowledge, and Google Scholar until April 2021, as well as references to the relevant articles retrieved. Random-effects models were used to calculate summary relative risk (RR) and 95% confidence intervals (CIs) for the highest vs. lowest categories of egg and dietary cholesterol intake. Also, linear and non-linear dose–response analyses were conducted to examine the dose-response relationships.

Results

We included 55 studies, comprising data from 2,772,486 individuals with 228,425, 71,745, and 67,211 cases of all-cause, CVD, and cancer mortality, respectively. Intake of each additional egg per day was associated with a 7% higher risk of all-cause (1.07, 95% CI: 1.02–1.12, I² = 84.8%) and a 13% higher risk of cancer mortality (1.13, 95% CI: 1.06–1.20, I² = 54.2%), but was not associated with CVD mortality (1.00, 95% CI: 0.92–1.09, I² = 81.5%). Non-linear analyses showed increased risks for egg consumption of more than 1.5 and 0.5 eggs/day, respectively. Each 100 mg/day increment in dietary cholesterol intake was associated with a 6% higher risk of all-cause mortality (1.06, 95% CI: 1.03–1.08, I² = 34.5%) and a 6% higher risk of cancer mortality (1.06, 95% CI: 1.05–1.07, I² = 0%), but was not associated with CVD mortality (1.04, 95% CI: 0.99–1.10, I² = 85.9%). Non-linear analyses demonstrated elevated risks of CVD and cancer mortality for intakes more than 450 and 250 mg/day, respectively.

Conclusions and Relevance

High-dietary intake of eggs and cholesterol was associated with all-cause and cancer mortality. Little evidence for elevated risks was seen for intakes below 0.5 egg/day or 250 mg/day of dietary cholesterol. Our findings should be considered with caution because of small risk estimates and moderate between-study heterogeneity.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=252564, PROSPERO, identifier: CRD42021252564.

Associations of Dietary Cholesterol, Serum Cholesterol, and Egg Consumption With Overall and Cause-Specific Mortality: Systematic Review and Updated Meta-Analysis

BACKGROUND

Despite substantial research highlighting the importance of exogenous dietary cholesterol intake and endogenous serum cholesterol level in human health, a thorough evaluation of the associations is lacking. Our study objective was to examine overall and cause-specific mortality in relation to dietary and serum cholesterol, as well as egg consumption, and conduct an updated meta-regression analysis of cohort studies.

METHODS

We conducted a prospective analysis of 27 078 men in the ATBC Study (Alpha-Tocopherol, Beta-Carotene Cancer Prevention). Multivariable-controlled cause-specific Cox proportional hazards regression models were used to calculate hazard ratios and 31-year absolute mortality risk differences. A systematic review and meta-analysis of cohort studies was also performed (PROSPERO [URL: https://www.crd.york.ac.uk/prospero/; Unique identifier: CRD42021272756]).

RESULTS

Based on 482 316 person-years of follow-up, we identified 22 035 deaths, including 9110 deaths from cardiovascular disease (CVD). Greater dietary cholesterol and egg consumption were associated with increased risk of overall and CVD-related mortality. Hazard ratios for each additional 300 mg cholesterol intake per day were 1.10 and 1.13 for overall and CVD-related mortality, respectively; for each additional 50-g egg consumed daily, hazard ratios were 1.06 and 1.09, respectively, for overall and CVD-related mortality (all P values<0.0001). After multivariable adjustment, higher serum total cholesterol concentrations were associated with increased risk of CVD-related mortality (hazard ratios per 1 SD increment, 1.14; P<0.0001). The observed associations were generally similar across cohort subgroups. The updated meta-analysis of cohort studies on the basis of 49 risk estimates, 3 601 401 participants, and 255 479 events showed consumption of 1 additional 50-g egg daily was associated with significantly increased CVD risk (pooled relative risk, 1.04 [95% CI, 1.00-1.08]; I²=80.1%). In the subgroup analysis of geographic regions (P_interaction=0.02), an increase of 50-g egg consumed daily was associated with a higher risk of CVD in US cohorts (pooled relative risk, 1.08 [95% CI, 1.02-1.14]) and appeared related to a higher CVD risk in European cohorts with borderline significance (pooled relative risk, 1.05), but was not associated with CVD risk in Asian cohorts.

CONCLUSIONS

In this prospective cohort study and updated meta-analysis, greater dietary cholesterol and egg consumption were associated with increased risk of overall and CVD-related mortality. Our findings support restricted consumption of dietary cholesterol as a means to improve long-term health and longevity.

Egg Consumption and Risk of All-Cause and Cause-Specific Mortality: A Systematic Review and Dose-Response Meta-analysis of Prospective Studies

The association between egg consumption and mortality is extremely debatable. This study aimed to investigate the potential dose-response association of egg consumption with risk of mortality from all causes and cause-specific in the general population. The primary comprehensive literature search was conducted in PubMed/Medline, Scopus, ISI Web of Science, and Embase up to March 2021, as well as reference lists of relevant original papers and key journals. We calculated summary RRs and their 95% CIs for the highest and lowest categories, as well as the linear trend estimation of egg intake, using the random-effects model. Thirty-three (32 publications) cohort studies were included. These studies enrolled 2,216,720 participants and recorded 232,408 deaths from all causes. Comparing highest versus lowest egg intake categories was not associated with the risk of mortality from all causes (RR: 1.02; 95% CI: 0.94, 1.11; n = 25), cardiovascular disease (CVD) (RR: 1.04; 95% CI: 0.87, 1.23, n = 11), coronary heart disease (CHD) (RR: 0.98; 95% CI: 0.84, 1.16; n = 10), stroke (RR: 0.81; 95% CI: 0.64, 1.02; n = 9), and respiratory disease (RR: 0.96; 95% CI: 0.53, 1.71; n = 3); however, it was associated with a higher risk of cancer mortality (RR: 1.20; 95% CI: 1.04, 1.39; n = 13). In the linear dose-response analysis, an additional intake of 1 egg per week was associated with a 2% and 4% increased risk of all-cause and cancer mortality, respectively, and a 4% decreased risk of stroke mortality. The certainty of the evidence was rated as low to moderate. Higher egg consumption was not associated with an increased risk of mortality from all causes, CVD, CHD, stroke, or respiratory disease, whereas an elevated risk was observed for cancer mortality. These findings suggest that eggs be consumed in low to moderate amounts (≤1 egg/d) as part of a healthy diet.

Egg Consumption and Blood Lipid Parameters According to the Presence of Chronic Metabolic Disorders: The EVIDENT II Study

CONTEXT

Egg consumption is one of the main dietary sources of cholesterol, but whether individuals who eat more eggs have a worse blood lipid profile remains controversial.

OBJECTIVE

We examined the relationship between egg consumption and lipid parameters and explored whether this relationship changes according to the presence of chronic metabolic disorders.

METHODS

A multicenter cross-sectional study was conducted with adult participants in the EVIDENT II trial. Adjusted linear regression models were stratified by the main chronic metabolic disorders.

RESULTS

Among the 728 participants (61.9% women, mean age 52.1 ± 11.9 years), the mean egg consumption was equivalent to 5 to 6 eggs per week for a 70-kg individual. In the fully adjusted analysis, no association was found of egg consumption with total and high-density lipoprotein cholesterol (HDL-c), and triglyceride levels. Furthermore, compared with the first quartile of consumption, the fourth quartile was associated with lower low-density lipoprotein cholesterol (LDL-c) levels (coefficient -7.01; 95% CI -13.39, -0.62) and a lower LDL-c/HDL-c ratio (coefficient -0.24, 95% CI -0.41, -0.06). In the analyses stratified by chronic metabolic diseases, higher egg consumption was not associated with lipid profile in those with obesity, hypertension, type 2 diabetes, dyslipidemia, or treated with hypolipidemic drugs, and was associated with a better lipid profile in participants without these conditions.

CONCLUSION

Higher egg consumption was not associated with blood lipids in individuals with chronic metabolic disorders. In individuals without such conditions, the lipid profile was better among those who consumed more eggs. Our findings support current guidelines recommending eggs as part of a healthy diet.

A review of research on the intersection between breast cancer and cardiovascular research in the Women's Health Initiative (WHI)

Both obesity and metabolic syndrome are linked to increased incidence of type 2 diabetes, cardiovascular disease (CVD), and cancers of the breast (post-menopausal), and other obesity-related cancers. Over the past 50 years, the worldwide prevalence of obesity and metabolic syndrome has increased, with a concomitant higher incidence of associated co-morbidities and mortality. The precise mechanism linking metabolic syndrome to increased cancer incidence is incompletely understood, however, individual components of metabolic syndrome have been linked to increased breast cancer incidence and worse survival. There is a bidirectional relationship between the risk of CVD and cancer due to a high burden of shared risk factors and higher rates of CVD among cancer survivors, which may be impacted by the pro-inflammatory microenvironment associated with metabolic syndrome and cancer-directed therapies. The Women's Health Initiative (WHI) is an excellent resource to study a dual relationship between cancer and CVD (cardio-oncology) with extensive information on risk factors and long-term outcomes. The purpose of this review is to provide an overview of research on cardio-oncology conducted utilizing WHI data with focus on studies evaluating both breast cancer and CVD including shared risk factors and outcomes after cancer. The review also includes results on other obesity related cancers which were included in the analyses of breast cancer, articles looking at cancer after heart disease (reverse cardio-oncology) and the role of Clonal Hematopoiesis of Indeterminate Potential (CHIP) as a shared risk factor between CVD and cancer. A summary of pertinent WHI literature helps to delineate the direction of future research evaluating the relationship between CVD and other cancer sites, and provides information on the opportunity for other novel analyses within the WHI.

Cholesterol and Egg Intakes with Cardiometabolic and All-Cause Mortality among Chinese and Low-Income Black and White Americans

We examined the associations of dietary cholesterol and egg intakes with cardiometabolic and all-cause mortality among Chinese and low-income Black and White Americans. Included were 47,789 Blacks, 20,360 Whites, and 134,280 Chinese aged 40–79 years at enrollment. Multivariable Cox models with restricted cubic splines were applied to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for mortality outcomes using intakes of 150 mg cholesterol/day and 1 egg/week as the references. Cholesterol intake showed a nonlinear association with increased all-cause mortality and a linear association with increased cardiometabolic mortality among Black Americans: HRs (95% CIs) associated with 300 and 600 mg/day vs. 150 mg/day were 1.07 (1.03–1.11) and 1.13 (1.05–1.21) for all-cause mortality (P-linearity = 0.04, P-nonlinearity = 0.002, and P-overall < 0.001) and 1.10 (1.03–1.16) and 1.21 (1.08–1.36) for cardiometabolic mortality (P-linearity = 0.007, P-nonlinearity = 0.07, and P-overall = 0.005). Null associations with all-cause or cardiometabolic mortality were noted for White Americans (P-linearity ≥ 0.13, P-nonlinearity ≥ 0.06, and P-overall ≥ 0.05 for both). Nonlinear inverse associations were observed among Chinese: HR (95% CI) for 300 vs. 150 mg/day was 0.94 (0.92–0.97) for all-cause mortality and 0.91 (0.87–0.95) for cardiometabolic mortality, but the inverse associations disappeared with cholesterol intake > 500 mg/day (P-linearity ≥ 0.12; P-nonlinearity ≤ 0.001; P-overall < 0.001 for both). Similarly, we observed a positive association of egg intake with all-cause mortality in Black Americans, but a null association in White Americans and a nonlinear inverse association in Chinese. In conclusion, the associations of cholesterol and egg intakes with cardiometabolic and all-cause mortality may differ across ethnicities who have different dietary patterns and cardiometabolic risk profiles. However, residual confounding remains possible.

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.