Are eggs just a heart-attack fuse waiting to be lit? While it has been increasingly accepted by the general public that eggs, and in particular, dietary cholesterol aren’t as bad as we once thought, a recent observational study published by JAMA has given eggs a bit of a beating.
The study was a pooled analysis of data from 6 different studies and it involved 30,000 participants over 17 years. The results?
Among US adults, higher consumption of dietary cholesterol or eggs was significantly associated with higher risk of incident CVD and all-cause mortality in a dose-response manner.
Specifically, the researchers found that for each additional 300 milligrams a day of cholesterol in the diet, there was a 17% increased risk of cardiovascular disease and an 18% increased risk of premature death from any cause. In relation to that: since a large egg has about 185 milligrams of cholesterol (with all of that contained in the egg yolk), each additional half-egg a day was associated with a 6% increased risk of cardiovascular disease and an 8% increased risk of early death.
Those numbers do sound scary and convincing, I know. But do not dump the trays of eggs on your kitchen table-top into the trashcan and swear off morning eggs for all of eternity just yet — it turns out that there are a lot of gaps in information and assumptions when we take a closer look at the study.
Studies are indeed more meaningful when you have a larger pool of data, or participants but in this case, the (almost) 30,000 participants were a result of combining 6 studies where the information was collected in different manners.
As if that was not confounding enough: this study was also based on dietary self-report — what participants recall having eaten over a period of weeks. I’m not sure about you, but I can’t even remember what I had for dinner yesterday. Researchers also only assessed this once, and assumed the number didn’t change in an average of 17 years of follow-up.
Now tell me, are you eating the same number of eggs as you did 17 years before?
It is also important to note that many other lifestyle factors contribute to cardiovascular risk. BMI, weight, smoking, and exercise factors were admitted to be crucial contributing factors to cardiovascular risk but were not adequately factored in when it came to the study’s conclusions.
If you still think I’m crazy for eating 3 eggs daily, I don’t blame you — let me just throw in a few more studies which might just convince you. Before that though, how well do you know eggs?
Heck, let me just do a very quick introduction.
Hi, this is Egg
The albumen — the white of the egg — is mostly water and protein. It also contains the anti-nutrient avidin, a protein that can bind to certain B-vitamins (such as biotin) and prevent their absorption. Thankfully, heat (including pasteurisation) destroys avidin: I trust that you like to have your eggs cooked because otherwise, you’re facing possible nutrient loss!
Ah, the devil as portrayed by the devil and those fond of fear-mongering. The yolk is mostly made of fatty acids, cholesterol, and fat-soluble nutrients. A notable mention goes to choline, a nutrient associated with a number of health benefits. While the egg yolk is lower in protein in comparison to the albumen, it contains higher concentrations of leucine, an essential amino acid.
Other studies on egg consumption and heart health
No association between egg consumption and risk of cardiovascular disease has been found in observational studies in middle-aged Japanese people and in people on a Mediterranean diet. Another observational study has also found no increase in the risk of stroke of coronary artery disease in people consuming 1–6 eggs per week.
In short, observational studies which have looked at egg consumption specifically (rather than at overall dietary cholesterol in the case of the JAMA study) have not found it to be associated with any form of cardiovascular disease.
Randomised controlled trials
Healthy college students were randomised to eat either a breakfast with 2 eggs or without eggs 5 times a week for 14 weeks. The study found that when eggs were added to the diets of healthy college students, risk factors for cardiovascular health, insulin sensitivity or blood glucose did not worsen.
To sum it all up, if you are an otherwise healthy individual, as long as you don’t exceed 6 eggs a day, an extra egg (or two! — eggs are yummy) in addition to your usual has not been shown by the current available scientific literature to be harmful to your coronary health. Enjoy your (cooked) eggs!
Thanks for reading! If you want an evidence-based approach to nutrition, start by learning how much protein you need for your goals. You’ll like it — I promise!