What’s The Real Story Behind That New Egg Study?
I swear that if I had five dollars for every new nutrition study that caused an unnecessary uproar, I’d be at Nordstrom buying shoes right now, not writing this blog. The phrase ‘unnecessary uproar’ brings me to that new egg study that was just published in JAMA.
Eggs and Cholesterol
The study, which looked at the association between egg consumption and cholesterol levels, has been in the media a lot this week, with headlines like, ‘eating as few as three eggs a week raises risk of heart disease’; ‘Eggs, cholesterol tied to higher risk of heart disease’; and ‘Egg consumption tied to higher heart disease and death risk’. With proclamations like those, it’s no wonder people are freaking out a bit.
Put any variation of the words ‘INCREASED RISK OF DEATH FROM SOMETHING YOU EAT A LOT OF’ on the cover of anything and that’s bound to happen.
The reality and findings of the study are, you’ll be relived to learn, a heck of a lot less exciting.
Are Eggs Healthy? This is what we know about eggs
I love eggs for their nutrients, including protein, lutein, zeaxanthin, vitamins A, D, E, B12, folate, choline, zinc, and iron.
Eggs have been vilified in the past because of their cholesterol content, which is around 300mg per egg. We now know though that dietary cholesterol doesn’t really affect blood cholesterol except in the few people we call hyper responders. Most of us can tolerate eggs and dietary cholesterol just fine.
Most of what makes our blood cholesterol rise is actually genetics. Sure, if you have a diet that’s high in saturated and trans fat, that can affect your cholesterol. But most people who eat well and have elevated blood cholesterol anyhow have livers that just make too much cholesterol. This is hereditary, so if your parents had high cholesterol, you’re more likely to have it too.
Aside from heredity, trans fat, and possibly saturated fats, other risk factors for the development of high cholesterol are possibly a diet high in refined carbohydrate, smoking, obesity, sedentary lifestyle, age, and diabetes.
For most healthy people, I’ve always recommended eggs in unlimited numbers and have no plans to stop. Who in the world eats that many eggs, anyhow?
Let’s see what the study actually found:
The study authors collected the data of just under 30,000 people over 17.5 years. These people were interviewed once about their diets, at the beginning of the study. By the end of the study, predictably, a number of people had gotten sick with heart disease. Some had died.
Researchers found that the participants who ate 2 eggs a day had a 27% higher risk of developing heart disease. Every 300mg of cholesterol a day added another 2.24% of having a cardiovascular event and a 4.43% risk of dying from a cardiovascular event.
While these numbers may seem ominous, let’s poke some holes in them. My favorite part!
First of all, this study is population-based. So while it can draw associations between two things, in this case egg intake and cardiovascular risk, it can’t prove causation. That means that while these two things may be related in some way, there’s no real proof that they are, so what we’re doing is taking more of an educated guess about their relationship.
People were interviewed once about their diets, 17.5 years before the study conclusions were drawn. My diet has changed a lot in 17.5 years, and theirs may have as well. Aside from that, the study didn’t control for the rest of their diets *facepalm*. That means that even if the participants ate eggs every single day of those 17.5 years, the study didn’t look at what else they ate.
It’s pretty safe to assume that these people didn’t eat only eggs for all that time, so what else were they eating? Their diets could have been full of saturated and trans fat-heavy, ultra-processed foods, alongside their eggs. Sausage, anyone?
While the study controlled for some lifestyle factors like activity level, smoking, and alcohol use, it didn’t look at others, such as socioeconomic status, and stress levels. These can also have an impact on someone’s risk of a heart attack, can they not?
So are Eggs Bad For You?
Let’s not drill our diets down to individual foods and nutrients. If you eat a well-varied, balanced diet, as boring as that is of me to say, you’ll be FINE.
Don’t let sensationalized nutrition headlines bother or scare you.
Correlation does not equal causation, and a study that doesn’t control for diet over 17 years isn’t telling us much about how eggs affect our health.
Blood cholesterol is affected by many things, such as genetics, saturated/trans fats, smoking, diabetes, obesity, and age. Most people can tolerate dietary cholesterol well without significant effects to their blood cholesterol. If your cholesterol is high and you suspect the culprit might be your diet, try taking out higher sat fat foods and refined carbs, increasing fiber, and adding healthy fats like avocado, nuts, and olive oil to your diet.
Like my dad used to tell me, ‘there’s risk, and then there’s just plain bad luck’. Eat your eggs. Enjoy.
Want to read more? Learn about if sugar in fruit is bad for you.