This comes after academics analysed the dietary habits of 4241 residents, aged 35 to 70 years, in Sabzevar city, Iran. The cases group comprised 1535 individuals recently diagnosed (within two months) with heart diseases, ischemia, infarction, and high blood pressure, while the control group consisted of 2706 healthy individuals.
A comprehensive food frequency questionnaire (FFQ), covering 168 commonly consumed Iranian food items, was employed in face-to-face interviews to assess food consumption over the past year. Nutrient intake was evaluated using a food composition table, with participants providing information on their habitual egg consumption over the last 12 months.
Additionally, a Persian cohort general questionnaire gathered demographic details, medical and family history of cardiovascular diseases, smoking and alcohol habits, and physical activity levels.
Measurements of systolic and diastolic blood pressure were taken three times, with the average of the last two measurements considered for each participant, and height and weight measurements were also recorded.
Correlation found between egg consumption and increased stroke risk
In the comparison between the cases and control groups, the former exhibited significantly higher age, weight, BMI, systolic and diastolic blood pressure, as well as incidences of diabetes and triglyceride, while the latter had notably higher physical activity, height, serum cholesterol, low-density lipoprotein, and smokers.
Regarding nutrient intake, the cases group showed lower levels of protein, total fat, carbohydrate, energy, and cholesterol compared to the control group.
Although there was no significant association between egg consumption and the risk of cardiovascular diseases after adjusting for various factors, the control group had significantly lower egg consumption than the cases group (25.31 ± 31.73 vs. 74.8 ± 31.73 g/d, p < 0.001).
Notably, the researchers identified a positive association between dietary egg intake and stroke risk after adjusting for multiple factors, including physical activity, BMI, blood pressure, smoking, alcohol consumption, diabetes, and nutrient intake.
Nevertheless, the study findings, as emphasised by the researchers, may be influenced by a significant measurement bias inherent in self-reported dietary data. Furthermore, the lack of information regarding the preparation methods of eggs introduces uncertainty about their nutritional contents.
As such, the results cannot be broadly applied due to its observational nature and variations in nutritional habits and chronic disease epidemiology within this group of participants.
Dietary recommendation for those at-risk of stroke
Addressing nutritional risk factors stands as a crucial strategy in global efforts to alleviate the burden of cardiovascular diseases.
While dietary cholesterol has been extensively studied and often linked to an increased risk of cardiovascular diseases, the specific mechanisms through which eggs may influence this risk remain unclear and sometimes contradictory.
Past research has noted associations between egg consumption and other unhealthy behaviours such as smoking, poor dietary patterns, and low physical activity. But in the current study, none of this was detected. Researchers believe such inconsistency might stem from individual differences in responses to dietary cholesterol.
On the other hand, a previous study had shown 8% increased risk of coronary heart disease with each additional half egg consumed but the present study discovered that participants in the cases group had lower dietary cholesterol intake, and a significant positive association between egg consumption and stroke persisted even after adjusting for cholesterol levels.
This suggests that the adverse link between eggs and stroke may be independent of egg cholesterol content. The heightened risk of heart disease might be attributed to the choline content of eggs. Some choline may convert to trimethylamine by gut microbiota, further oxidizing in the liver to trimethylamine-N-oxide (TMAO), a compound associated with increased atherosclerosis.
“Further studies should be performed to establish a causal relationship between eggs consumption and the risk of CVDs,” researchers wrote.
“[However] there was a significant association between egg intake and stroke. Dietary recommendations for egg consumption should be adjusted for people at risk of stroke.”
Source: BMC Cardiovascular Disorders
Egg consumption and risk of cardiovascular disease: a PERSIAN cohort-based study
Authors: Golsa khalatbari Mohseni et al.