By Kelley Herring
It wasn’t long ago that an image of eggs sunny-side up graced the cover of Time magazine. The questioning caption on the cover read “Is Eating Eggs as Bad for Your Heart as Smoking?”.1
The study featured in that issue was published in the journal, Atherosclerosis. In that study, the researchers measured plaque build-up in the arteries of over 1,200 men and women. These subjects had all filled out lifestyle questionnaires at heart-health clinics, providing details about their use of medications, cigarette smoking and consumption of egg-yolks.
The study evaluated how much people smoked and how many egg yolks they consumed over time. And they used this data to calculate two measure that they called “pack-years” (packs of cigarettes smoked per day times the number of years) and “egg-yolk years” (egg yolks consumed per week times the number of years).
The researchers concluded that those who ate the most egg yolks developed more arterial plaque over time and that this “follows a similar pattern to that of cigarette smoking.”2 The study states that:
“Our findings suggest that regular consumption of egg yolk should be avoided by persons at risk of cardiovascular disease.”
Of course, if you’re hip to the low-fat lies we’ve been told for decades and you’ve seen studies like this before, you already know the inherent problems with this erroneous conclusion.
Population studies such as this can NEVER be used to show causation or conclusive “proof” of anything. At best, they provide clues to correlation and may help to identify leads to explore with tightly-controlled clinical research studies.
The reasons why these “epidemiological studies” are flawed are obvious. First and foremost, these studies are not controlled. In this case, the primary source of “data” were questionnaires, based on the subjects’ memory. Of course, it is also impossible for the researchers to weed out conflicting and confounding factors.
For example, how were the eggs cooked? Were they fried in vegetable oil? Were they served with hash browns, toast and orange juice? Did the people who ate egg yolks also consume soft drinks? What about refined carbohydrates and trans-fats? How much physical activity did they pursue? What about their stress levels?
We will never know the answers to these questions, because these factors were not studied. But we DO know ALL of those factors impact risk and incidence of heart disease and the development of plaque in the arteries.
Don’t Blame the Eggs for What the Toast Did
Despite the vilification of cholesterol and saturated fat, we know that dangerous plaque in the arteries only develops in the presence of inflammation.
And when it comes to our diet, inflammation is primarily driven by our blood sugar, levels of polyunsaturated fats, and our microbiome.
Researchers discovered two years ago that an animal-based diet, low in carbohydrate and rich in saturated fat and cholesterol, actually shifts the bacteria inside of our microbiome to a composition that uniquely protects against heart disease.3
Another recent study found yet another way eating eggs can help protect the health of the heart…
Eating Eggs Boosts Heart-Healthy Metabolites
A 2018 study published in the journal Heart included approximately half a million adults who ate eggs daily (about one per day). Researchers found these individuals had a substantially lower risk of heart disease and stroke than those who ate eggs less frequently.
Researchers used a technique called targeted nuclear magnetic resonance to measure 225 metabolites in the participants’ blood. Of these metabolites, they identified 24 associated with self-reported levels of egg consumption.
Those who ate a moderate amount of eggs had higher levels of a protein in their blood called apolipoprotein A1 – a key building-block of HDL. This so-called “good” cholesterol helps clear cholesterol from the blood vessels and protects against heart attack and stroke.4
The participants who ate fewer eggs had lower levels of these beneficial metabolites and higher levels of harmful ones in their blood, compared to those who ate eggs more regularly. Regarding their results, the lead researcher of this study, a professor at Peking University, states that:
“Our results provide a potential explanation for how eating a moderate amount of eggs can help protect against heart disease”
An Animal-Based Diet for Heart Health
When it comes to the health of your heart, focus on an anti-inflammatory diet rich in animal foods – including beef, wild fish, pastured pork and poultry, traditional fats, like tallow, lard and coconut oil… and EGGS!
You should also keep an eye on your omega-6 intake (from seeds, nuts and vegetable/seed oils). And keep carbohydrates and sugars to a bare minimum.
Check your levels of inflammation (especially CRP and homocysteine) regularly and consider getting your coronary artery calcium checked if you are at high risk for heart disease.
Read more health and nutrition articles from Kelley Herring on our Discover Blog. Want to learn more about which eggs are best…see our article, Free-range vs. Pasture-raised: Which Eggs are Best?
Love comfort foods, but not the carbs? Check out Kelley’s FREE new book – Carb Lover’s Keto – with 100 recipes for all of your favorite comfort foods. From Chicken Parmigiana and Coconut Shrimp to Buffalo Wings and Pizza. Discover how you can indulge – 100% guilt free!
- Spence JD, Jenkins DJ, Davignon J. Egg yolk consumption and carotid plaque. Atherosclerosis. 2012 Oct;224(2):469-73. doi: 10.1016/j.atherosclerosis.2012.07.032. Epub 2012 Aug 1. PMID: 22882905.
- Veronika Kivenson, Stephen J. Giovannoni. An Expanded Genetic Code Enables Trimethylamine Metabolism in Human Gut Bacteria. mSystems, 2020; 5 (5) DOI: 10.1128/mSystems.00413-20
- Lang Pan, Lu Chen, Jun Lv, Yuanjie Pang, Yu Guo, Pei Pei, Huaidong Du, Ling Yang, Iona Y Millwood, Robin G Walters, Yiping Chen, Weiwei Gong, Junshi Chen, Canqing Yu, Zhengming Chen, Liming Li. Association of egg consumption, metabolic markers, and risk of cardiovascular diseases: A nested case-control study. eLife, 2022; 11 DOI: 10.7554/eLife.72909