1.
Egg consumption and risk of cardiovascular disease: three large prospective US cohort studies, systematic review, and updated meta-analysis.
Drouin-Chartier, JP, Chen, S, Li, Y, Schwab, AL, Stampfer, MJ, Sacks, FM, Rosner, B, Willett, WC, Hu, FB, Bhupathiraju, SN
BMJ (Clinical research ed.). 2020;368:m513
-
-
-
Free full text
-
Plain language summary
Eggs have a high cholesterol content and have therefore been associated with a risk for heart disease. However, studies to substantiate this have been conflicting, with some studies showing associations and others not. This systematic review and meta-analysis of over five million people and 763 studies aimed to evaluate the association between egg intake and the risk of heart disease. The results showed that higher egg intake was associated with a poor diet. Egg intake was not associated with heart disease and this was evident even in people who ate at least one egg per day. Even in people with other associated diseases, such as type 2 diabetes and high blood pressure, egg intake was not associated with heart disease. It was concluded that egg consumption does not increase an individual’s risk for heart disease. This study could be used by healthcare professionals to justify the recommendation that patients at risk of heart disease or those who have heart disease, can still eat up to one egg per day, without risk of exacerbating their condition.
Abstract
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.
2.
Dietary intake of total, animal, and plant proteins and risk of all cause, cardiovascular, and cancer mortality: systematic review and dose-response meta-analysis of prospective cohort studies.
Naghshi, S, Sadeghi, O, Willett, WC, Esmaillzadeh, A
BMJ (Clinical research ed.). 2020;370:m2412
-
-
-
Free full text
Plain language summary
Eating a diet high in protein, particularly from plants, has been linked to improvements in indicators for heart disease. However, links to reduction in heart disease, cancer and death remain controversial. This systematic review and meta-analysis of 32 cohort papers aimed to investigate the associations between dietary protein intake and the risk of death, death due to heart disease and death due to cancer. The results showed that total protein and animal protein intake did not affect the risk of death due to heart disease. However, increased plant protein intake decreased the risk of death from heart disease, and this was apparent from as little as an additional 3% of energy from plant proteins per day. Death from any cause decreased as protein and plant protein intake increased, but animal protein alone had no effect. Death due to cancer was not affected by the amount of dietary protein, animal protein, or plant protein. It was concluded that this study supports the recommendation of higher dietary plant protein in the general population to reduce the risk of death by any cause and death due to heart disease and healthcare professionals could use this study to justify this decision.
Abstract
OBJECTIVE To examine and quantify the potential dose-response relation between intake of total, animal, and plant protein and the risk of mortality from all causes, cardiovascular disease, and cancer. DESIGN Systematic review and meta-analysis of prospective cohort studies. DATA SOURCES PubMed, Scopus, and ISI Web of Science until December 2019, and references of retrieved relevant articles. STUDY SELECTION Prospective cohort studies that reported the risk estimates for all cause, cardiovascular, and cancer mortality in adults aged 18 or older. DATA SYNTHESIS Random effects models were used to calculate pooled effect sizes and 95% confidence intervals for the highest versus lowest categories of protein intake and to incorporate variation between studies. Linear and non-linear dose-response analyses were done to evaluate the dose-response relations between protein intake and mortality. RESULTS 32 prospective cohort studies were included in the systematic review and 31 in the meta-analysis. During the follow-up period of 3.5 to 32 years, 113 039 deaths (16 429 from cardiovascular disease and 22 303 from cancer) occurred among 715 128 participants. Intake of total protein was associated with a lower risk of all cause mortality (pooled effect size 0.94, 95% confidence interval 0.89 to 0.99, I2=58.4%, P<0.001). Intake of plant protein was significantly associated with a lower risk of all cause mortality (pooled effect size 0.92, 95% confidence interval 0.87 to 0.97, I2=57.5%, P=0.003) and cardiovascular disease mortality (pooled hazard ratio 0.88, 95% confidence interval 0.80 to 0.96, I2=63.7%, P=0.001), but not with cancer mortality. Intake of total and animal protein was not significantly associated with risk of cardiovascular disease and cancer mortality. A dose-response analysis showed a significant inverse dose-response association between intake of plant protein and all cause mortality (P=0.05 for non-linearity). An additional 3% energy from plant proteins a day was associated with a 5% lower risk of death from all causes. CONCLUSIONS Higher intake of total protein was associated with a lower risk of all cause mortality, and intake of plant protein was associated with a lower risk of all cause and cardiovascular disease mortality. Replacement of foods high in animal protein with plant protein sources could be associated with longevity.
3.
Dietary Glycemic Index and Load and the Risk of Type 2 Diabetes: Assessment of Causal Relations.
Livesey, G, Taylor, R, Livesey, HF, Buyken, AE, Jenkins, DJA, Augustin, LSA, Sievenpiper, JL, Barclay, AW, Liu, S, Wolever, TMS, et al
Nutrients. 2019;11(6)
-
-
-
Free full text
Plain language summary
It is generally accepted that certain diet and lifestyle choices contribute to a person’s risk of developing type 2 diabetes (T2D). In this meta-analysis, researchers set out to review previous studies and assess whether there is any evidence that the amount and type of carbohydrate (measured by Glycaemic Index (GI) and Glycaemic Load (GL)) in a person’s diet has a direct influence on their risk of developing T2D. The authors concluded with a high level of confidence that eating high GI and GL foods can lead to a higher risk of developing T2D. They suggest that nutrition advice that favours low GI and GL foods could produce significant cost savings for public healthcare.
Abstract
While dietary factors are important modifiable risk factors for type 2 diabetes (T2D), the causal role of carbohydrate quality in nutrition remains controversial. Dietary glycemic index (GI) and glycemic load (GL) have been examined in relation to the risk of T2D in multiple prospective cohort studies. Previous meta-analyses indicate significant relations but consideration of causality has been minimal. Here, the results of our recent meta-analyses of prospective cohort studies of 4 to 26-y follow-up are interpreted in the context of the nine Bradford-Hill criteria for causality, that is: (1) Strength of Association, (2) Consistency, (3) Specificity, (4) Temporality, (5) Biological Gradient, (6) Plausibility, (7) Experimental evidence, (8) Analogy, and (9) Coherence. These criteria necessitated referral to a body of literature wider than prospective cohort studies alone, especially in criteria 6 to 9. In this analysis, all nine of the Hill's criteria were met for GI and GL indicating that we can be confident of a role for GI and GL as causal factors contributing to incident T2D. In addition, neither dietary fiber nor cereal fiber nor wholegrain were found to be reliable or effective surrogate measures of GI or GL. Finally, our cost-benefit analysis suggests food and nutrition advice favors lower GI or GL and would produce significant potential cost savings in national healthcare budgets. The high confidence in causal associations for incident T2D is sufficient to consider inclusion of GI and GL in food and nutrient-based recommendations.