Eggs and Autoimmune Diseases: The Truth You Need to Know

Let’s get one thing clear right away: eggs should absolutely be part of your diet, especially grass-fed eggs, which are rich in omega-3 fatty acids. Chicken eggs are generally a nutritious food, providing a good source of selenium, vitamin A, vitamin D, B vitamins, and several essential minerals.

Additionally, numerous recent experimental and epidemiological studies (1, 2) suggest that regular egg consumption (7 per week) does not increase the risk of coronary heart disease (CHD). While eggs are one of the most concentrated sources of dietary cholesterol (212 mg per egg), dietary cholesterol has minimal effect on blood cholesterol levels for most people (1, 3).

Moreover, high-cholesterol egg-based diets increase HDL particles (the “good” cholesterol that removes excess cholesterol from the body) (1) and reduce small, dense LDL particles, which are highly atherogenic, while simultaneously increasing larger, less atherogenic LDL particles (4, 5).

So, should everyone include eggs in their daily diet? Not necessarily, especially when examined through an evolutionary lens.

Undoubtedly, our pre-agricultural ancestors would have collected and eaten bird eggs whenever possible, but in the wild, bird eggs are only seasonally available. Thus, pre-agricultural humans would not have consumed two eggs for breakfast every morning of the year, as some people do today. Instead, they would have eaten them occasionally for just a few weeks or months.

If we follow the evolutionary model and look closer, eggs do have some nutritional deficiencies that may be problematic, especially for people with autoimmune diseases or allergies.

Although eggs are classified as an animal food and grouped with meats in the USDA’s My Pyramid (the official dietary guidelines in the U.S.), eggs are uniquely different from meats in that they represent reproductive targets for adult birds, existing outside the mother’s body in a semi-permeable, warm compartment.

As a result, all eggs are particularly vulnerable to invasion, attack, and destruction by microorganisms like fungi, bacteria, and viruses present in their nesting environment. The egg white protein is not just a simple protein; it’s a conglomeration of multiple proteins designed by natural selection to cause toxic and lethal effects on bacteria and microorganisms, much like the food lectins found in grains and legumes (12).

For any dietary protein to potentially trigger or promote autoimmune disease, it must:

1. Survive intact through human digestion,
2. Cross the intestinal barrier intact, either alone or attached to other proteins,
3. Interact with the immune system in a way that could trigger autoimmune disease.

Several egg white proteins meet these criteria. The most problematic is lysozyme, a protein found in egg whites. It’s actually an enzyme known as N-acetylglucosaminidase, which is also found in many human tissues, including tears (13).

Lysozyme’s function in both egg whites and human tears is to act as a potent bactericide, binding to and dissolving bacterial cell walls (13).

Lysozyme is unusual among the major egg white proteins because it has an alkaline isoelectric point (pI), meaning it can form strong complexes with other egg white proteins, including ovomucin, ovoalbumin, and ovotransferrin (6, 13). So, while lysozyme is a benign enzyme produced by our bodies, when we eat egg white lysozyme, it presents itself as a compound attached to other foreign egg white proteins.

In the human digestive tract, enzymes called proteases typically break down proteins into their constituent amino acids, allowing them to be absorbed through the intestine. However, egg white protein contains high concentrations of protease inhibitors (ovomucoid, ovoinhibitor, ovostatin, cystatin), which make human intestinal proteases (mainly trypsin and chymotrypsin) less effective in degrading egg white proteins and lysozyme/egg white protein complexes.

Additionally, lysozyme remains stable in the acidic environment of the intestines (13), arriving intact in the lower gastrointestinal tract.

So, what’s the problem if lysozyme/egg white protein complexes are not broken down by normal digestion? Typically, these protein complexes easily cross the intestinal barrier and enter the bloodstream, where they can interact with the immune system.

Again, lysozyme is unusual because it crosses the intestinal barrier quickly and enters human circulation (14). Lysozyme and the complexes it forms with other egg white proteins can cross the intestinal barrier because lysozyme contains a sugar (15, 16) that specifically binds to an intestinal receptor—the epidermal growth factor receptor (EGF-R)—allowing these protein complexes to enter circulation.

Remember, lysozyme also binds to intestinal bacterial cell walls, meaning these peptides can also enter circulation through this Trojan horse mechanism. Once the lysozyme/egg white protein/bacterial cell wall protein complex gains access to circulation, it has the potential to activate the immune system through a process called three-way molecular mimicry (12).

In genetically susceptible individuals, this process causes the immune system to lose the ability to distinguish between the body’s own proteins and foreign proteins, eventually leading the immune system to attack and destroy the body’s tissues.

Conclusion: If you suffer from an autoimmune disease like Hashimoto’s thyroiditis, multiple sclerosis, rheumatoid arthritis, or others, I have previously recommended a diet free of grains, dairy, and legumes.

To that list, you may also want to add eggs for the reasons explained above. Eliminate all these foods for an extended period (4-6 weeks) and closely monitor your symptoms. You can then reintroduce individual foods gradually into your diet to see if they trigger any issues.

Mediterranean diets, vegan, vegetarian, calorie-restricted diets, etc., will almost always lead to physical and mental deterioration, especially if you are predisposed to certain conditions.

Let food heal you, or medicine will feed you.

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