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

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.

Diet Quality and Mortality among Chinese Adults: Findings from the China Health and Nutrition Survey

The association between diet quality and all-cause mortality in Chinese population is unclear. We aimed to study the associations of three a priori diet quality indices-including the Diet Quality Index-International (DQI-I), Chinese Healthy Eating Index (CHEI), and energy-adjusted Dietary Inflammatory Index (E-DII)-and their included components with all-cause mortality. We used baseline data from the 2004, 2006, 2009, and 2011 waves of the China Health and Nutrition Survey (CHNS). We used a multivariable-adjusted Cox model to examine the associations between DQI-I, CHEI, and E-DII with all-cause mortality. During a mean of 7 years of follow-up, a total of 461 deaths occurred among 12,914 participants. For DQI-I, there were significant inverse associations with mortality for the variety score (HRQ4 vs. Q1 = 0.69, 95%CI = 0.52-0.92) and overall balance score (HR>0 vs. 0 = 0.81, 95%CI = 0.66-0.91). The adequacy score of CHEI was associated with 40% less risk of all-cause mortality (HRQ4 vs. Q1 = 0.60, 95%CI = 0.43-0.84). E-DII was not associated with mortality. An estimated 20.1%, 13.9%, and 31.3% of total mortality would be averted if the DQI-I variety score, DQI-I overall balance score, and CHEI adequacy score improved from the bottom to the top quartile, respectively. Improving diet quality, especially improving diet variety and adequacy, and having a more balanced diet may reduce all-cause mortality in Chinese adults.

Cross-sectional measurement of adherence to a proposed sustainable and healthy dietary pattern among United States adults using the newly developed Planetary Health Diet Index for the United States

BACKGROUND

Dietary choices are an important avenue for improving food system sustainability. The Planetary Health Diet was proposed by the EAT-Lancet Commission as a reference healthy and sustainable dietary pattern.

OBJECTIVES

To assess adherence to the Planetary Health Diet among United States adults, this study developed and evaluated the Planetary Health Diet Index for the United States (PHDI-US), adapted from the original PHDI validated in the Brazilian population.

METHODS

The PHDI-US has 16 components with scores ranging between 0 and 150, and higher scores indicate better adherence to the Planetary Health Diet. Cross-sectional dietary data from 4741 participants of the National Health and Nutrition Examination Survey 2017-2018 were used to assess the validity and reliability of the PHDI-US.

RESULTS

Validity and reliability tests were acceptable overall: principal component analysis identified 6 components; total PHDI-US and Healthy Eating Index-2015 scores were positively associated (β = 0.67, standard error = 0.03, P <0.0001; R2 = 0.39); concurrent-criterion validity analyses identified significantly lower scores among males, everyday smokers, and younger adults; and the Cronbach's α value was 0.54. The average PHDI-US score was 46.7 out of 150, indicating that the diets of United States adults were far from meeting Planetary Health Diet recommendations. Based on component PHDI-US scores, many United States adults may be able to enhance the quality and sustainability of their diets by increasing intake of plant-based foods, including whole grains, nuts and peanuts, legumes, fruits, and vegetables, and reducing intake of animal-based foods, including red and processed meats.

CONCLUSIONS

The PHDI-US is a new tool that can assess adherence to the Planetary Health Diet and identify key aspects of United States adults' diets that could be altered to potentially improve dietary sustainability and quality.

Associations of low-carbohydrate diets with breast cancer survival

BACKGROUND

The objective of this study was to evaluate the role of low-carbohydrate diets after breast cancer diagnosis in relation to breast cancer-specific and all-cause mortality.

METHODS

For 9621 women with stage I-III breast cancer from two ongoing cohort studies, the Nurses' Health Study and Nurses' Health Study II, overall low-carbohydrate, animal-rich low-carbohydrate, and plant-rich low-carbohydrate diet scores were calculated by using food frequency questionnaires collected after breast cancer diagnosis.

RESULTS

Participants were followed up for a median 12.4 years after breast cancer diagnosis. We documented 1269 deaths due to breast cancer and 3850 all-cause deaths. With the use of Cox proportional hazards regression and after controlling for potential confounding variables, we observed a significantly lower risk of overall mortality among women with breast cancer who had greater adherence to overall low-carbohydrate diets (hazard ratio for quintile 5 vs. quintile 1 [HRQ5vsQ1 ], 0.82; 95% CI, 0.74-0.91; ptrend  = .0001) and plant-rich low-carbohydrate diets (HRQ5vsQ1 , 0.73; 95% CI, 0.66-0.82; ptrend < .0001) after breast cancer diagnosis but not animal-rich low-carbohydrate diets (HRQ5vsQ1 , 0.93; 95% CI, 0.84-1.04; ptrend  = .23). However, greater adherence to overall, animal-rich, or plant-rich low-carbohydrate diets was not significantly associated with a lower risk of breast cancer-specific mortality.

CONCLUSIONS

This study showed that greater adherence to low-carbohydrate diets, especially plant-rich low-carbohydrate diets, was associated with better overall survival but not breast cancer-specific survival among women with stage I-III breast cancer.

The effect of green tea supplementation on the anthropometric outcomes in overweight and obese women: a time and dose-response meta-analysis of randomized controlled trials

Inconsistencies are evident within the literature regarding the role of Green Tea (GT) supplementation on women living with obesity. To address this, we conducted to determine the impact of GT supplementation on the weight, body mass index (BMI), and waist circumference (WC) in overweight and obese women using time and dose-response meta-analysis of randomized controlled trials (RCTs). This meta-analysis searched electronic Scopus, Web of Science, Embase, and PubMed/Medline databases from inception to December 1^st, 2022. Data were reported as weighted mean difference (WMD) with 95% confidence interval (CI). A total of 2061 references were identified, and 15 articles with 16 RCT arms on body weight, 17 RCT arms on BMI, and 7 RCT arms on WC were included in the meta-analysis. GT supplementation significantly decreases body weight (WMD: -1.23 kg, 95% CI: -2.13 to -0.33, p = 0.007), BMI (WMD: -0.47 kg/m², 95% CI: -0.87 to -0.07, p = 0.020) and WC (WMD: -3.46 cm, 95% CI: -6.75 to -0.16, p = 0.040). In subgroup analyses, GT consumption demonstrated lowered body weight with dosaes ≥1000 mg/day (WMD: -1.38 kg), in the RCTs, which lasted ≥8 wk (WMD: -1.24 kg). The non-linear dose-response assessment detected a negative correlation between the changes in body weight and BMI in green tea consumption of more than 1000 (mg/day). The GT supplementation reduced the weight, BMI, and WC in overweight and obese women. In clinical practice, healthcare professionals can recommend using GT with dosages ≥ 1000mg/day and duration ≥ 8 wk in obese women.

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.

Comparing Lifestyle Modifications and the Magnitude of Their Associated Benefit on Cancer Mortality

Many cancers are associated with poor diet, lack of physical activity, and excess weight. Improving any of these three lifestyle factors would likely reduce cancer deaths. However, modifications to each of these-better nutrition, enhanced activity and fitness, and loss of extra body fat-have different effect sizes on cancer mortality. This review will highlight the relative benefit that each lifestyle change, enacted prior to a diagnosis of cancer, might impart on cancer-related deaths, as well as attempt to quantify the changes required to derive such a benefit. The review relies primarily on epidemiological data, with meta-analyses serving as the backbone for comparisons across interventions and individual studies within the larger meta-analyses providing the data necessary to form more quantitative conclusions. The reader can then use this information to better understand, recommend, and implement behaviors that might ultimately reduce cancer mortality. Of all the interventions, it seems clear that exercise, specifically improving cardiorespiratory fitness, is the best way to decrease the risk of dying from cancer.

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

There is an equivocal and inconsistent association between legume consumption and health outcomes and longevity. The purpose of this study was to examine and quantify the potential dose-response relationship between legume consumption and all-cause and cause-specific mortality in the general population. We conducted a systematic literature search on PubMed/Medline, Scopus, ISI Web of Science, and Embase from inception to September 2022, as well as reference lists of relevant original papers and key journals. A random-effects model was used to calculate summary HRs and their 95% CIs for the highest and lowest categories, as well as for a 50 g/d increment. We also modeled curvilinear associations using a 1-stage linear mixed-effects meta-analysis. Thirty-two cohorts (31 publications) involving 1,141,793 participants and 93,373 deaths from all causes were included. Higher intakes of legumes, compared with lower intakes, were associated with a reduced risk of mortality from all causes (HR: 0.94; 95% CI: 0.91, 0.98; n = 27) and stroke (HR: 0.91; 95% CI: 0.84, 0.99; n = 5). There was no significant association for CVD mortality (HR: 0.99; 95% CI: 0.91, 1.09; n =11), CHD mortality (HR: 0.93; 95% CI: 0.78, 1.09; n = 5), or cancer mortality (HR: 0.85; 95% CI: 0.72, 1.01; n = 5). In the linear dose-response analysis, a 50 g/d increase in legume intake was associated with a 6% reduction in the risk of all-cause mortality (HR: 0.94; 95% CI: 0.89, 0.99; n = 19), but no significant association was observed for the remaining outcomes. The certainty of evidence was judged from low to moderate. A higher legume intake was associated with lower mortality from all causes and stroke, but no association was observed for CVD, CHD, and cancer mortality. These results support dietary recommendations to increase the consumption of legumes.

Egg Consumption, Cardiovascular Disease and Cardiometabolic Risk Factors: The Interaction with Saturated Fatty Acids. Results from the ATTICA Cohort Study (2002-2012)

Purpose: To examine the association of egg intake with 10-year risk of cardiovascular disease (CVD) and other cardiometabolic risk factors in a sample of individuals of Mediterranean origin. Methods: In 2001−2002, n = 1514 men and n = 1528 women (>18 years old) from the greater Athens area, Greece, were enrolled. Information on any egg intake, eaten as a whole, partly or in recipes was assessed via a validated semi-quantitative food frequency questionnaire. Follow-up for CVD evaluation (2011−2012) was achieved in n = 2020 participants (n = 317 CVD cases). Results: Ranking from lowest (<1 serving/week) to intermediate (1−4 servings/week) and high (4−7 servings/week) egg consumption tertiles, lower CVD incidence was observed (18%, 9% and 8%, respectively, p-for-trend = 0.004). Unadjusted analysis revealed that 1−3 eggs/week and 4−7 eggs/week were associated with a 60% and 75%, respectively, lower risk of developing CVD compared with the reference group (<1 egg/week). When adjusting for sociodemographic, lifestyle and clinical factors, significance was retained only for 1−3 eggs/week (hazard ratio (HR) = 0.53, 95% confidence interval (95% CI) = 0.28, 1.00). When total saturated fatty acid (SFA) intake was taken into account, this inverse association was non-significant. Multi-adjusted analysis revealed that in participants of low SFA intake, 1 serving/day increase in egg intake resulted in 45% lower risk of developing CVD. In the case of higher SFA consumption, only 1−3 eggs/week seemed to protect against CVD (HR = 0.25, 95% CI = 0.07, 0.86). In the case of intermediate cardiometabolic disorders, no significant trend was observed. Conclusions: Overall dietary habits principally in terms of SFA intake may be detrimental to define the role of eggs in cardiac health.

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.

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.