Intake of eggs was associated, largely through cholesterol intake, with higher all-cause, cardiovascular disease, and cancer mortality, while intake of egg whites or egg substitutes was negatively associated with death, in a large data analysis of the NIH-AARP Diet and Health Study.
The study was led by Yu Zhang of Zhejiang University College of Biosystems Engineering and Food Science, Jingjing Jiao of Zhejiang University School of Medicine, China, and colleagues.
Whether consumption of egg and cholesterol is detrimental to cardiovascular health and longevity is highly debated, and data from large-scale cohort studies are scarce. In the new study, researchers used data on 521,120 participants from the NIH-AARP Diet and Health Study. Participants were aged 50-71 years old, 41.2% women, 91.8% non-Hispanic white, and were recruited from 6 states and 2 cities in the US between 1995 and 1996.
During a mean follow-up of 16 years, 129,328 deaths occurred in the cohort. Whole egg consumption, as reported in a food questionnaire, was significantly associated with higher all-cause mortality after adjusting for demographic characteristics and dietary factors (P<0.001), but not after further adjusting for cholesterol intake (P=0.64). Every intake of an additional 300 mg dietary cholesterol intake per day was associated with a 19% higher all-cause mortality (95% CI 1.16-1.22) and each additional half a whole egg per day was associated with a 7% higher all-cause mortality (95% CI 1.06-1.08). In contrast, egg whites/substitutes consumption was significantly associated with lower all-cause mortality (P<0.001). Replacing half a whole egg with an equivalent amount of egg whites/substitutes was associated with a reduction of 3% in cardiovascular disease mortality.
“Our findings suggest limiting cholesterol intake and replacing whole eggs with egg whites/substitutes or other alternative protein sources for facilitating cardiovascular health and long-term survival,” the authors say.
Why was this study done?
The 2015–2020 dietary guidelines for Americans recommend eating as little dietary cholesterol as possible while consuming a healthy eating pattern, but also state cholesterol is not a nutrient of concern for overconsumption.
There is limited and inconclusive evidence on the associations of egg or dietary cholesterol intake with all-cause and cardiovascular disease mortality.
Associations of egg or dietary cholesterol intake with mortality from non-cardiovascular causes, including cancer, respiratory disease, diabetes, and Alzheimer disease, are largely unknown.
What did the researchers do and find?
We used data on 521,120 participants from the NIH-AARP Diet and Health Study with a median follow-up of 16 years to assess the associations of egg and cholesterol intakes with all-cause and cause-specific mortality.
Whole egg and cholesterol intakes were positively associated with risk of all-cause and major cause-specific mortality, whereas egg white/substitute consumption was inversely associated with mortality.
Mediation models estimated that the increased mortality associated with whole egg intake was largely influenced by cholesterol intake.
Replacing half a whole egg with egg whites/substitutes or other protein sources containing less cholesterol is associated with lower overall mortality and mortality from major causes, including cardiovascular disease, cancer, and respiratory disease.
What do these findings mean?
The current recommendations for egg and dietary cholesterol intake from the US dietary guidelines might lead to increases in cholesterol intake, which could be detrimental to the prevention of premature death.
Clinicians and policy makers should continue to highlight limiting cholesterol intake in the US dietary recommendations, considering our results.
The US dietary guidelines may recommend replacing whole eggs with egg whites/substitutes or alternative protein sources for facilitating cardiovascular health and long-term survival.
Study details
Egg and cholesterol consumption and mortality from cardiovascular and different causes in the United States: A population-based cohort study
Pan Zhuan, Fei Wu, Lei Mao, Fanghuan Zhu, Yiju Zhang, Xiaoqian Chen, Jingjing Jiao, Yu Zhang
Published in PLOS Medicine on 9 February 2021
Abstract
Background
Whether consumption of egg and cholesterol is detrimental to cardiovascular health and longevity is highly debated. Data from large-scale cohort studies are scarce. This study aimed to examine the associations of egg and cholesterol intakes with mortality from all causes, cardiovascular disease (CVD), and other causes in a US population.
Methods and findings
Overall, 521,120 participants (aged 50–71 years, mean age = 62.2 years, 41.2% women, and 91.8% non-Hispanic white) were recruited from 6 states and 2 additional cities in the US between 1995 and 1996 and prospectively followed up until the end of 2011. Intakes of whole eggs, egg whites/substitutes, and cholesterol were assessed by a validated food frequency questionnaire. Cause-specific hazard models considering competing risks were used, with the lowest quintile of energy-adjusted intake (per 2,000 kcal per day) as the reference. There were 129,328 deaths including 38,747 deaths from CVD during a median follow-up of 16 years. Whole egg and cholesterol intakes were both positively associated with all-cause, CVD, and cancer mortality. In multivariable-adjusted models, the hazard ratios (95% confidence intervals) associated with each intake of an additional half of a whole egg per day were 1.07 (1.06–1.08) for all-cause mortality, 1.07 (1.06–1.09) for CVD mortality, and 1.07 (1.06–1.09) for cancer mortality. Each intake of an additional 300 mg of dietary cholesterol per day was associated with 19%, 16%, and 24% higher all-cause, CVD, and cancer mortality, respectively. Mediation models estimated that cholesterol intake contributed to 63.2% (95% CI 49.6%–75.0%), 62.3% (95% CI 39.5%–80.7%), and 49.6% (95% CI 31.9%–67.4%) of all-cause, CVD, and cancer mortality associated with whole egg consumption, respectively. Egg white/substitute consumers had lower all-cause mortality and mortality from stroke, cancer, respiratory disease, and Alzheimer disease compared with non-consumers. Hypothetically, replacing half a whole egg with equivalent amounts of egg whites/substitutes, poultry, fish, dairy products, or nuts/legumes was related to lower all-cause, CVD, cancer, and respiratory disease mortality. Study limitations include its observational nature, reliance on participant self-report, and residual confounding despite extensive adjustment for acknowledged dietary and lifestyle risk factors.
Conclusions
In this study, intakes of eggs and cholesterol were associated with higher all-cause, CVD, and cancer mortality. The increased mortality associated with egg consumption was largely influenced by cholesterol intake. Our findings suggest limiting cholesterol intake and replacing whole eggs with egg whites/substitutes or other alternative protein sources for facilitating cardiovascular health and long-term survival.
[link url="https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1003508"]PLOS Medicine study (Open access)[/link]
See also MedicalBrief archives:
[link url="https://www.medicalbrief.co.za/archives/one-egg-per-day-does-not-increase-cvd-risk-harvard-meta-analysis/"]One egg per day does not increase CVD risk — Harvard meta-analysis[/link]
[link url="https://www.medicalbrief.co.za/archives/moderate-egg-consumption-not-tied-to-risk-of-heart-disease/"]Moderate egg consumption not tied to risk of heart disease[/link]
[link url="https://www.medicalbrief.co.za/archives/egg-day-significantly-reduce-cvd-risk/"]An egg a day could significantly reduce CVD risk[/link]