Eggs are one of the Paleo staple foods. They are nutrient powerhouses – filled with amino acids, cholesterol and wonderful whole food sources of choline, which is quite rare. We are not going to rewrite the ‘why cholesterol isn’t bad for you’ argument here, but a useful source of information on this would be Chris Kresser.
So – beyond the cholesterol – why are Eggs such a highly prized food? And why are they then eliminated the moment you enter into an Autoimmune Protocol?
The Hunter-Gatherer Diet Debate
This is a pretty quick section: hunter-gatherers ate Eggs. Not just chickens’ Eggs but Eggs from everything that laid them that lived alongside them in their habitat.
Modern Egg Consumption
Now we are more likely to eat chickens’ Eggs, and possibly ducks’ and quails’ Eggs. Occasionally you might see a fancy chef cook a goose or ostrich Egg, but you won’t find them casually in the supermarket.
In a Modern Paleo diet Eggs form part of the foundation of breakfasts, simply because all cereals and toasts are removed when there is a grain-free approach. This makes Eggs (every which way) and omelettes, little Egg tortillas and muffin-case-baked Egg things a pretty permanent feature of an easy, relatively quick Paleo breakfast. Eggs also make the baking of Paleo ‘treats’ possible, and are actually very useful sources of all-round nutrition.
In fact, Eggs are possibly the single-most-missed food on an Autoimmune Protocol because losing Eggs from the diet makes breakfast and baking incredibly challenging.
But what of the modern Egg – are we really getting the nutrition that hunter-gatherers once were?
The truth is that with the Egg, as well as meat and dairy produce, quality is everything. The nutrient profile of an Egg is entirely dependent on the feed of the bird that laid it, and whether that bird was subjected to any hormones and/or antibiotics in its life.
Good quality Eggs carry far higher levels of amino acids, and interestingly they have a better ratio of Omega-3 to Omega-6 fatty acids than factory-farmed eggs. This is largely down to the diet – because as you may have read elsewhere on this site – animals are built using the foods they consume. Animals fed on grains will produce poorer nutrition all-round.
For a real insight into Omega 3s and 6s and the difference between Organic, Free-Range, Pastured Eggs and the normal supermarket Egg our Deeper Science article on Grass-fed Meat and Pastured Chickens goes into the details.
The Dark Side of the Egg
As you may have read, our ethos is that a food should include more nutrients that anti-nutrients in order to be included on a Paleo diet. You would think that from the above explanation of the nutritional value of Eggs they would be a shoe-in for inclusion. And yet Eggs are, quite simply, one of the top ten food allergens. This means they rank alongside wheat, dairy, soy, shellfish and peanuts as a food capable of creating powerful immune responses in those who are sensitive. This ‘immune response’ can be anything from an autoimmune condition to anaphylaxis, but the fact that the Egg can prove so aggravating and inflammatory means that for those with impaired health or immune conditions, consuming Eggs may add fuel to the fire.
Of course, the reactivity of Eggs is a completely individual phenomenon. Many people will be absolutely fine with Eggs. And yet it seems that there are many with autoimmune concerns who are never able to successfully reintroduce Eggs, even after some years of attaining symptom remission.
The inflammatory and immune-activating potential of Eggs might be down to the fact that an Egg is actually supposed to become a whole new life: new chickens/ducks/quails etc. This means that much like the hormonal and immune changes that occur within a pregnant human mother, a bird’s Egg contains protective substances to guard the embryo from microbial invasions which would threaten the burgeoning life.
At the head of this ‘protection army’ is an enzyme called Lysozyme. Lysozyme is held within the Egg white and can break down the cell wall of any invading microbes. That’s great news for the Egg. It’s less good news for the humans who then eat the Egg white, Lysozyme and all.
Lysozyme forms strong complexes with other proteins – like those that accompany it within the Egg white. It is largely left intact by human digestion, which means that these proteins all come along within a Lysozyme complex and are hard to break down. Some of the proteins bound up in the Lysozyme complex from the Egg white are known protease/trypsin inhibitors, neither of which will break down the Lysozyme or allow the complex to be broken down. Lysozyme can also break down the cell wall and bind up protein fragments from gram-negative bacteria in the GI tract.
This wonderful resulting ‘complex’ would be fine, if it stayed where it was. The issue with Lysozyme is that it has a quirk of maintaining a slightly positive electrical charge. This means it becomes attracted to specific glycoproteins embedded in the surface of enterocytes (cells which line the human gastrointestinal wall) which are negatively charged. This is enough to let the Lysozyme (and its accompanying complex) pass through the intestinal wall. Whilst Eggs in normal quantities will cause Lysozyme to transfer into circulation in everyone, the levels that access the bloodstream are nowhere near enough to create issues… for most people.
Leaky Lysozyme and Inflammation
Humans do not actually have a problem with Lysozyme itself. In fact, we make a form of Lysozyme in our bodily secretions because it is exceptionally good at binding to any bacterial infections that come towards us. The issue arises because Lysozyme binds to other things before crossing the GI tract. It is these ‘other things’ which cause inflammatory and immunological problems.
As with all proteins that arrive where they shouldn’t be, particularly in large quantities, the immune system will react accordingly and mount an inflammation response to any proteins (and bacterial fragments) that the Lysozyme carries into circulation.
It is perhaps not surprising then that those with really healthy guts and fully functioning, alert immune systems have less of an issue with Eggs. Whilst Lysozyme has been shown to cross the barrier within everyone, in healthier individuals any circulating toxins or proteins are easily identified and dealt with by the body.
In individuals with compromised health there are other factors at play. To begin with Intestinal Permeability may already be a factor (for other reasons, such as gluten consumption and increased zonulin production) and in cases such as this, the Lysozyme transport across the GI tract wall is far easier, leading to increased circulating toxins and proteins.
Secondly, those with immune hypersensitivity and an already up-regulated inflammatory response will have an increased inflammatory and immune response to any proteins and bacterial fragments which appear in circulation. This could result in the immune system creating antibodies to certain proteins which will cause that protein to create a reaction every time it is seen in the future. It could also, and is highly likely to, result in mass, systemic inflammation as the immune system attempts what it sees as a host of rogue, invading foreign entities.
In anyone with an autoimmune condition the immune system is prepped and on high alert, waiting for anything that might aggravate and trigger an inflammatory response. Consuming Eggs, with the Lysozyme’s ability to introduce ‘foreign’ proteins into circulation where they should not be, is like waving a red flag to the overzealous immune system and pushing it to respond.
How to Eat Eggs
So yes, Eggs are a superfood for those who can tolerate them and who are relatively healthy. But they do come with their own challenges. How well each individual tolerates eggs will mostly depend on how susceptible they are to the mechanism, and to the overt triggering of inflammation, as explained above.
For those on AIP this is something that can only be discovered after a trial of elimination and subsequent reintroduction. But even for those following a Paleo regimen, we would definitely recommend that at some point a trial period without any Eggs is attempted. On Paleo Eggs can become such a staple that you are having them every day, if not multiple times a day. To truly understand whether this is really healthy for you, going for a week or two without them will provide you with valuable information as to how healthy Eggs really are – for you.
Have you eliminated Eggs and now need to Reintroduce? Our Guide to Reintroductions on AIP shows you how.