A Brief History Of The Egg

For millennia, the hen was an egg machine first. Then 1948 happened, and we forgot.

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Sixty thousand years ago, in what is now the Western Cape of South Africa, somebody built a fire in a rock shelter and ate eggs.

We know this because they left the shells. Thousands of them. Ostrich eggshells, fragmented across the hearths of the Diepkloof Rock Shelter, in such quantities that archaeologists have spent decades cataloguing them. A single ostrich egg contains the equivalent of roughly twenty chicken eggs, give or take, and these were being cracked, cooked, and eaten in numbers that suggest this was not a special occasion. This was Tuesday.

The ostrich was almost certainly annoyed about it. There is no kind way to take eggs from an ostrich. They are eight feet tall, can outrun a horse over short distances, and have a kick that will shatter a femur with the casual disinterest of a man closing a car door. Stone-age humans evidently weighed the risks against the reward of an entire brunch service in shell form, and decided the femur was worth gambling.

The egg has been on the menu for as long as we have been here to put it on a menu. What is interesting, and what this article is actually about, is the absurd journey it has taken since.

It has been worshipped as a god. It has been the most reliable food in pre-modern Europe. It has been singled out, alone amongst all foods on earth, for restriction by the world’s largest health body, on the basis of a hypothesis that turned out to be wrong. The warning lasted forty-seven years and was retracted in a sentence. And throughout all of this, the egg quietly carried on being one of the most nutrient-dense things you can put in your mouth, while the bird that lays it was systematically rebred into a fundamentally different animal entirely.

Get comfortable. This is going to take a while.

Before The Farm

The honest answer to “did our pre-agricultural ancestors eat eggs” is: almost certainly yes, but the evidence is patchy in the way that all pre-agricultural evidence is patchy. Eggshell does not preserve as well as bone. It crumbles. It dissolves. Diepkloof is unusual in that the conditions happened to favour preservation. Most sites of comparable antiquity simply do not give us the receipts.

What we can say is this. Where archaeology does turn up eggshell, it tends to turn up rather a lot of it. The same pattern shows up across multiple paleolithic sites in southern and eastern Africa. We can also look at modern hunter-gatherer populations, who eat wild eggs whenever they encounter them, with a consistency that suggests this is not a clever modern invention but a default behaviour. If you are a creature with hands and an appetite, and you find a nest, the nest gets raided. This is not complicated.

What we should be careful about is overselling the case. Wild eggs were probably an opportunistic food rather than a staple. Birds nest seasonally, in places that are often deliberately inaccessible to ground-based predators, and the calorie return on climbing a tree to fight a goshawk for three eggs is questionable on a good day. So eggs were a known food. Not a daily one, but not a novel one either. By the time agriculture arrived, the human relationship with the egg was already several hundred thousand years old. We just did not yet have a bird obliging enough to lay them on demand.

That was about to change.

The Bird That Was Too Sacred To Eat

The chicken, at least the version that ended up in your fridge, descends from the red junglefowl of Southeast Asia. Domestication probably began somewhere between seven and ten thousand years ago, although the exact timing is contested because the bones of small fowl preserve poorly and identifying them is genuinely difficult work. The interesting bit is not when. The interesting bit is why.

For a long time, the assumption was that chickens were domesticated for food. Recent work suggests this is wrong, or at least incomplete. The earliest chickens appear to have been kept for cockfighting, for ritual purposes, and very probably for status. They were exotic. They looked unusual. They made surprising noises at four in the morning. They were not, initially, dinner.

The clearest illustration of this comes from Iron Age Britain. Chickens arrived in the British Isles around 800 BC, brought in by traders from continental Europe, and the British response was immediate and unambiguous. They worshipped them.

Archaeologists working in Hampshire and Hertfordshire have excavated chicken burials from the period and found the birds buried whole, intact, with no butchery marks on the bones. Some were buried alongside their human owners. Hens went with women, cockerels went with men, and the entire arrangement screams “beloved companion” rather than “leftover Sunday lunch.”

This was not a fringe theory hatched by archaeologists with too much time on their hands. We have a primary source on this, and the primary source is Julius Caesar. In his account of the Gallic Wars, written in the first century BC, he records that the Britons “consider it contrary to divine law to eat the hare, the chicken, or the goose. They raise these, however, for their own amusement and pleasure.”

This is Julius Caesar, a man who had a fairly relaxed attitude to most things, recording with mild bewilderment that the locals were too pious to eat their own poultry. The same man, incidentally, who would shortly invade and start the process of teaching them otherwise.

When the Romans got properly settled in Britain, they did what Romans tended to do, which was make everything pragmatic, well-organised, and slightly less fun. Chickens went from sacred objects to farmed livestock within a few generations. By the third century AD, the British were tucking into roast chicken with the enthusiasm of people who had spent eight hundred years staring at a perfectly good food source and refusing to acknowledge it.

But here is the bit that matters for our purposes. Even when chicken became food, the chicken’s primary value was not its meat. It was its eggs.

Two Thousand Years Of The Egg Economy

For most of recorded history, the hen was a small, portable, self-replicating protein factory, and the protein she produced came out the back end in a perfect single-serving package roughly twice a day. The carcass, when she eventually stopped laying, was a bonus rather than the point.

This is not a stylistic claim. It is a basic fact of pre-industrial economics. A hen, kept on table scraps and whatever she could scratch up in the yard, would lay between fifty and a hundred and fifty eggs a year, depending on the breed and the season. That is somewhere between four and twelve kilograms of complete protein, fat-soluble vitamins, and minerals, produced at near-zero feed cost, by an animal that took up almost no space and could be kept by anyone with a back garden.

Killing the hen for one meal of stringy, inedible meat after she had spent five years performing this miracle was a decision so economically deranged that almost no peasant household would have made it voluntarily. You ate the eggs. You ate the cockerels, occasionally, because there was no point keeping them around once they had done their job. The hen herself was killed only when she stopped laying, and even then, the resulting bird was so tough that medieval cookbooks tend to describe it as something best simmered for half a day with whatever you had to hand.

This is the egg economy that ran across most of Europe, Asia, and North Africa for the better part of two thousand years. From the Roman occupation to the dawn of the twentieth century, the chicken was an egg machine first, and a meat carcass a distant, reluctant second. People understood this intuitively. Nobody had to explain it to them.

Then 1948 happened.

The Chicken Of Tomorrow

In 1948, the Great Atlantic and Pacific Tea Company, then America’s largest poultry retailer, launched a competition. It was called the Chicken of Tomorrow contest, and the goal was straightforward. The post-war American population was booming, the country was exporting beef and pork to a war-shattered Europe, and there was suddenly enormous demand for cheap domestic protein. The existing American chicken, an egg-first dual-purpose bird that weighed somewhere between two and four pounds at sixteen weeks of age, was not going to cut it.

The Chicken of Tomorrow was supposed to be a different animal entirely. The organisers commissioned a wax model of the ideal bird, with a vast bulging breast, plump legs and thighs, and the proportions of an avian wrestler going through a cut. Breeders across America were invited to compete to produce the closest living approximation, with winning genetics rolled out commercially.

What followed over the next fifty years was one of the most aggressive selective breeding programmes in the history of domesticated animals. From 1957 to 2005, broiler chicken weight at six weeks of age increased by over four hundred percent. Body fat dropped from around twenty-seven percent in the 1970s to around fifteen percent by the early 2000s.

Modern broilers reach slaughter weight in six weeks, where their 1948 ancestors took sixteen. This is not a chicken in any meaningful sense that a Roman or a Victorian would recognise. This is a purpose-built, lean-protein delivery vehicle, optimised over decades to produce the maximum quantity of breast meat in the shortest possible time on the cheapest possible feed.

But here is the thing. The Chicken of Tomorrow was being designed at exactly the moment that the cholesterol scare was about to land. By the time the new lean broilers were rolling out across American supermarkets, the entire western world was being told that animal fat was the architect of heart disease. The lean, breast-heavy, fat-stripped broiler was, in retrospect, the perfect food for the era it was about to enter. It was almost as if someone had planned it.

The egg-laying hen, meanwhile, got her own entirely separate genetic line and quietly carried on doing what chickens have always done. Modern commercial layers can produce three hundred eggs a year, which is biologically remarkable, but the basic deal has not changed. She is still an egg machine first. The meat industry has its hen. The egg industry has its hen. And one of them got famous for the wrong reasons.

The Forty-Seven Year Warning

In 1968, the American Heart Association issued a recommendation that no individual should consume more than three egg yolks per week, and that total dietary cholesterol should be capped at three hundred milligrams a day.

This was, and remains, one of the strangest moments in the history of public health nutrition. The egg is the only food in human history to have been singled out, by name, for restriction by a major health body. Not seed oils. Not industrial sugar. Not processed grain products. The egg. The thing that paleolithic humans were literally fighting ostriches for.

The basis for the warning was the cholesterol hypothesis, which I have written about extensively elsewhere on this blog, and which most of you will have heard the gist of by now. Briefly, the theory ran that dietary cholesterol raised blood cholesterol, that blood cholesterol caused heart disease, and that therefore foods rich in dietary cholesterol were dangerous. The egg yolk, being one of the densest concentrations of dietary cholesterol in the food supply, was an obvious target.

The hypothesis was never validated in clinical trial. By the 1990s the evidence was overwhelming that for the vast majority of people, eating eggs did essentially nothing to their blood cholesterol levels. The warning, however, kept right on going. Generations of cardiologists trained patients to avoid the yolk. Restaurants started offering egg-white omelettes as a healthy option, an act of culinary vandalism that involves throwing away the entire nutritional payload and keeping the bit that does almost nothing. Bodybuilders bought cartons of liquid egg whites by the gallon, in the sincere belief that they were optimising their nutrition by removing the most nutrient-dense part of the food they were eating.

The egg consumption per capita in the United States dropped from around three hundred and seventy eggs a year in the late 1940s to around two hundred and thirty by the 1990s. That is not a small change. That is forty percent of an entire food removed from the average diet, on the basis of a recommendation that turned out to be wrong.

In 2015, forty-seven years after the original warning, the United States Dietary Guidelines Advisory Committee removed the cholesterol limit. The phrasing in the report was clinical and untheatrical. They simply noted that the available evidence showed no appreciable relationship between dietary cholesterol and serum cholesterol, and that therefore the recommendation would not be carried forward. There was no press conference. No mailout to the nation’s GPs. No apology to anyone who had spent half a century being told to scrape the yolk into the bin.

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Forty-seven years of advice, retired in a sentence buried on page somewhere of a four-hundred-page report. That was the entire ceremony. The warning had been mistaken, but admitting it required no fanfare, because admitting it would have invited questions about how it got there in the first place, and nobody wanted those questions.

The egg, indifferent to all of this, simply waited it out.

What’s Actually Inside

Now that the world has decided eggs are allowed again, it is worth taking a moment to look at what was being thrown away during those forty-seven years.

The yolk is the entire point of the egg. The white is mostly water and a single high-quality protein, which is fine, but it is not why the food exists. The yolk is the bit designed to grow a chicken from a single cell to a fully-formed vertebrate over the course of three weeks. To do that, it has to contain almost everything that vertebrate is going to need. Which it does.

A single large yolk delivers around a hundred and fifty milligrams of choline, which is one of the few nutrients that almost no modern population gets enough of. Choline is essential for the production of acetylcholine, a neurotransmitter that does small minor jobs like memory, learning, and muscle contraction. It is also critical for foetal brain development, which is why every credible source on prenatal nutrition now recommends pregnant women eat eggs daily. Two yolks gets you most of the way to the daily target. There is essentially no other food that delivers choline at this density.

The yolk contains all of the egg’s vitamin A, in its preformed retinol state, which is the form your body actually uses without having to perform conversion gymnastics on a plant precursor. It contains all of the vitamin D, all of the vitamin E, and the meaningful share of the vitamin K, in the K2 form that helps direct calcium into bones rather than arteries. It contains substantial B12, riboflavin, and folate, which is to say most of the B-vitamin spectrum in a single ingredient.

The yolk is one of the few sources of lutein and zeaxanthin in the human diet that the body can actually absorb properly. These are carotenoids that accumulate in the retina and protect against age-related macular degeneration, the leading cause of blindness in older adults. They exist in larger absolute quantities in dark leafy greens, but the fat in the yolk renders them several times more bioavailable than the same compounds in spinach or kale. You can eat all the kale you like. If there is no fat in the meal, most of the lutein walks straight out of you.

There is iron. There is zinc. There is selenium and iodine, both of which the average western diet is increasingly short on. There is the cholesterol your body uses as the raw material for every steroid hormone you produce, which includes the minor matters of testosterone, oestrogen, progesterone, cortisol, and vitamin D itself.

And all of this comes packaged in around seventy calories, in a self-contained, reusable, near-perfect serving size, that costs about thirty pence a unit at the time of writing and can be cooked five different ways before breakfast. The egg is the food equivalent of a Swiss Army knife, except the Swiss Army knife was banned for forty-seven years because someone misread the instructions.

The Best Use Of Chicken

Which brings us, finally, to the chicken.

The modern broiler is a triumph of mid-twentieth-century animal science. It is also, for anyone interested in an actually nutrient-dense diet, one of the more disappointing meats available.

The micronutrient profile is the first issue. Chicken meat, across all cuts, is markedly less nutrient-dense than ruminant meat. You get less B12. Less iron, and what iron is there is in a less bioavailable form. Less zinc. Less of the fat-soluble vitamins that ride along with proper animal fat. Liver-for-liver, ounce-for-ounce, beef and lamb deliver substantially more of almost everything that matters. The chicken came in second on the nutritional league table, and modern breeding has, if anything, widened the gap.

The fat profile is the second issue, and arguably the worse one. Chicken fat is dominated by polyunsaturated fats, specifically by linoleic acid, which is the omega-6 fatty acid that I have spent rather a lot of words warning you about elsewhere on this site. The reason the modern chicken is so high in omega-6 is straightforward.

Modern chickens are fed almost exclusively on grains and seed-derived feeds, and a chicken incorporates the fat it eats directly into its tissue. Whatever was in the feed bucket is, in a few weeks, in the meat. The omega-6 to omega-3 ratio in commercial chicken can run as high as twenty to one, where ruminant meat from grass-fed animals comes in closer to two or three to one.

This is not a problem with breast meat specifically. It is a problem with the whole bird. Thigh, drumstick, wing, skin, or breast, the fat is mostly the same fat, and most of it is the kind you would benefit from eating less of. The lean cuts have less fat overall, but the fat that is there carries the same profile.

The egg dodges almost all of this. The hen, evolved over millions of years to produce a complete starter kit for a developing chick, packages the yolk with a fat profile and micronutrient density that has very little to do with what she ate yesterday. The omega-6 content of an egg yolk is tempered by the deliberate inclusion of substantial amounts of the saturated and monounsaturated fats the embryo needs.

The choline, the fat-soluble vitamins, the minerals, all of this is there because the chick will not develop without it, not because the hen happened to encounter it in her feed. The yolk is a purpose-built nutrient package. The drumstick is a slab of muscle tissue passively absorbing whatever the bird walked through.

If you are eating chicken meat as your primary protein source because it has been recommended to you as the lean, healthy, low-fat option, you have been sold the answer to a question that the last forty years of nutritional science has revealed to be the wrong question entirely. The chicken’s actual contribution to human nutrition was always the egg. The meat was a bonus. The Romans understood this. The medieval peasant understood this. The Victorian smallholder understood this. We forgot it for about seventy years, and we are slowly remembering.

If you keep chickens in your diet, eat the eggs. Let someone else have the broiler.

Beatrice

In a back garden in Worcestershire, a Buff Orpington called Beatrice has just laid an egg.

Beatrice is four years old. She does not understand the cholesterol hypothesis. She has not read the 1968 American Heart Association recommendation, or the 2015 Dietary Guidelines Advisory Committee report that quietly retracted it. Beatrice is interested in three things, which are corn, the slugs that live under the upturned plant pot near the shed, and the specific patch of dust she likes to bathe in.

In the course of the last twelve months, Beatrice has produced approximately a hundred and ninety eggs. The eggs contain, in aggregate, around twenty-eight grams of choline, more bioavailable lutein than her owner could absorb from an industrial quantity of spinach, and enough complete protein to keep a single adult fed for a season. The cost to Beatrice’s owner is roughly fifteen pounds a month in feed. The cost to Beatrice is whatever Beatrice charges for being a chicken in a garden with slugs in it, which appears to be nothing.

Beatrice has not been bred over fifty years to grow four times faster than her ancestors. Beatrice has not had her body fat reduced from twenty-seven percent to fifteen by aggressive selection. Beatrice was not designed, in a wax model, to have plump thighs and an enormous breast. Beatrice is, broadly, the same animal that the Iron Age Britons buried with their dead, that the Romans started eating in the third century, and that paleolithic humans would probably have recognised in spirit if not in plumage.

Beatrice does not care about any of this. Beatrice is examining the upturned plant pot.

The egg outlasted the warning. The yolk survived the question.

Most things worth eating do.

T

The Livestock Series

This is part of an ongoing series on the animals that built civilisation and are now being blamed for ending it.

Why Cows Aren’t Bringing The Apocalypse

Cow: The Animal That Built The World

Sheep: The Animal That Built Britain

Keith Was Here First: The Goat’s Claim To Civilisation

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