Eggs are a very common and affordable food in everyday life. Although inexpensive, it is one of the main sources of high-quality protein that we consume every day, and one of the main sources of dietary cholesterol, a boiled egg (about 50 grams) contains about 200 mg of cholesterol. Eggs are also rich in other high-quality nutrients, including fatty acids, vitamin D, vitamin B12, selenium and choline.
However, the question of how many eggs a day has always been controversial.
Previously, a large number of studies have emphasized the importance of exogenous diets and endogenous serum cholesterol for human health, but it has not been possible to conduct a thorough and comprehensive examination of their relationship to long-term health outcomes. Dietary cholesterol is ingested through foods including eggs and chicken, duck and fish meat; endogenous serum cholesterol is synthesized in the liver and extrahepatic tissues and circulated in the bloodstream. For more than two decades, epidemiological studies have assessed the relationship between higher dietary cholesterol and egg intake and disease risk, but have come to conflicting conclusions. Some studies have shown a positive association between cholesterol intake and the risk of cardiovascular disease and death; others have shown no link or negative correlation between the two.
This disparity is due in part to flawed study design, small population sizes, short follow-up times, and issues with intake levels and confounding control, which have led to inconsistent evidence and conclusions on relevance.
As we all know, cardiovascular disease is the disease that has been on the global morbidity and mortality rankings for many years, with 18.6 million deaths in 2020 alone. Therefore, it is necessary to have a clear understanding of the relationship between egg intake and this terrible disease, as well as all-cause mortality.
Recently, in a new study published in Circulation, a top journal in the field of heart and cardiovascular system, a research team led by Huang Jiaqi, the Second Xiangya Hospital of Central South University and the Key Laboratory of Diabetes Immunology of the Ministry of Education, followed more than 27,000 participants for 31 years and found that the intake of one more egg per day was significantly related to the increased risk of all-cause death and the risk of death from cardiovascular disease.
The Dietary Guidelines for Chinese Residents 2021 recommend that the weekly intake of eggs be 280-350 grams, which is an average of one egg per day. The findings are in line with the latest version of the Dietary Guidelines.
In the new study, the researchers analyzed dietary cholesterol, serum cholesterol and egg intake data from 27,078 participants in a α-tocopherol, β-carotene cancer prevention (ATBC) study in Finland that began in 1985. The study was completed at the end of 2015.
In 482316-year-based follow-up (average 18.2 years), a total of 22,035 people died, including 9,110 deaths from cardiovascular disease (7,450 deaths from heart disease and 1,621 deaths from stroke) and 7,213 deaths from cancer.
The researchers analyzed both exogenous dietary cholesterol and endogenous circulating cholesterol to objectively and comprehensively examine the relationship between cholesterol and long-term health.
The results of the analysis showed that more dietary cholesterol and egg intake were significantly associated with an increased risk of all-cause and cardiovascular disease death. Serum cholesterol concentrations were also significantly positively associated with the risk of cardiovascular disease death.
However, in a subgroup analysis of geographic regions, eating an extra egg per day was associated with a higher risk of cardiovascular disease, but not with a risk of cardiovascular disease in the Asian cohort.
A study in China involving nearly 500,000 adults showed a negative correlation between moderate egg consumption and cardiovascular disease risk. Note: Is moderate intake. For Chinese, the premise of eating eggs with confidence is to reduce the intake of saturated fats (such as red meat and processed meat) at the same time to avoid excessive cholesterol intake.
The researchers found that the association of serum cholesterol with cardiovascular disease is largely independent of several other cardiovascular disease risk factors. As a major cause of death worldwide, atherosclerotic disease is triggered by the accumulation of lipids (including circulating cholesterol) in the arterial wall, which subsequently leads to local chronic inflammation and promotes the further development of atherosclerotic plaques. In addition to the initial plaque buildup, cholesterol can also increase the production and accumulation of oxysterols. These findings are consistent with previous studies.
Taken together, the study provides objective and convincing evidence for the association between egg intake and an increased risk of cardiovascular disease and death. These findings support limiting dietary cholesterol intake as a means of improving long-term cardiovascular health and longevity.
Thesis Link:
https://doi.org/10.1161/CIRCULATIONAHA.121.057642
Choreographer: Dai Wei Xia Bingbing