If you use food science to guide your diet and health, are eggs going to be on your plate?
The consumer pendulum has swung widely with an average of 400 eggs per person per year in 1945 that dropped to 229 in view of concerns over dietary cholesterol and heart disease. The current numbers show that annual egg consumption has climbed back to 279 or 5–6 eggs a week.
A study made headlines this month suggesting that egg consumption in type 2 diabetics, a group at particular risk for cardiovascular disease like heart attacks and strokes, was not harmful. Actually, there were 2 new reports, with conflicting results, but only one grabbed the headlines. In addition, there are many older studies to consider.
The New Study That Made Headlines
Researchers in Australia enrolled 128 subjects with prediabetes or type 2 diabetes as part of a weight loss study and randomized them to <2 eggs/week or >12 eggs/week. The end points were lab values for cardiac markers like glucose control, cholesterol, inflammation, and oxidative stress. At the end of the 9 months, there were no differences in the lab markers. Headlines like “eggs are safe for diabetics and heart health” were found in news feeds worldwide.
What was not mentioned in most of the news reports was the funding of the study by the Australian Egg Corporation and authors had received research grants from the Egg Nutrition Council. Also overlooked was the study design wherein those subjects assigned to the low egg group were instructed to increase their protein by more meat, chicken, fish, dairy, and legumes.
The New Study That Did Not Make Headlines
Researchers in Korea conducted a prospective cohort study of 9,248 Korean adults without cardiovascular diseases (CVD) or cancer at baseline and followed them for 7.3 years. During follow up, 570 cases of CVD were diagnosed. In the group with type 2 diabetes the consumption of 4 eggs/week vs none increased the risk of developing CVD by 2.8 times (280% increase). This assocation was not found in those without diabetes.
Key studies relating egg intake to disease states
1. Congestive heart failure
In a prospective study of approximately 70,000 Swedes, eating an egg a day or more was associated with an 30-percent increased risk of congestive heart failure.
A large analysis of eggs found that diabetics who eat eggs have a 50-percent increased risk of coronary heart disease.
3. Diabetes Mellitus
According to a meta-analysis of more than 200,000 subjects, people who eat three eggs a week have an increased risk of developing diabetes.
Diabetic patients who eat a large quantity of eggs double the risk of dying compared to those eating fewer eggs, so says a prospective study.
5. Carotid Artery Disease
In a prospective study of 1,262 persons undergoing serial ultrasound examinations of the carotid arteries to the brain, egg yolk consumption was correlated with increased amounts of carotid plaque.
6. Prostate cancer
A pooled study found that increased egg intake — along with red meat — was associated with a 14-percent increase in advanced and fatal prostate cancers.
7. Breast cancer
According to a meta-analysis that looked at eating eggs, consuming more than nine eggs a week was associated with a nine-percent increased risk of breast cancer.
8. Ovarian cancer
In a meta-analysis, egg consumption was found to relate to a 22-percent increased risk of ovarian cancer.
9. Colon cancer
In an analysis of more than 400,000 subjects, egg consumption correlated with the development of gastrointestinal cancers, especially a 25-percent increase in colon cancer.
Trimethylamine N-oxide (TMAO) is a molecule that causes cardiovascular and kidney disease and is related to the ingestion of certain foods. For example, in a research study, eating eggs increased TMAO in the blood significantly.
What will you do the next time you are at a café and the choice is oatmeal or fried eggs? A fruit plate or a frittata? As a medical doctor, if you are diagnosed with type 2 diabetes, I would reach for the plant option not the ovum. In addition, if you have ovaries, a colon, a prostate, breasts, a pancreas, arteries, or a pulse, think long and hard about the wealth of data that says the best egg meal is the one you skip over.