The Foyson Diet: Faeries, Essence, and My Findings...

I'd like to introduce some perhaps leading edge science, nutrition and folklore connections, and I think a gentle, relatable way to do that might be by explaining how and why I discovered them.

So..

My body runs on a very short list.

Fresh red beef, cooked as little as I can get away with. Fresh eggs, fresh butter, fresh whole milk. Every single day, without fail, or things go wrong quickly and measurably. The beef has to be red and it has to be recent, not aged, not cured, not frozen and thawed, not sitting in a display case under fluorescent lights accumulating the quiet chemical violence that processed meat accumulates when no one is paying attention to what's happening inside it. The butter has to be real. The milk has to be full-fat, unprocessed, and as close to the animal as my supply chain allows. I've lived on this list for most of my life, not because a nutritionist designed it for me, but because my body taught me through years of trial, error, and consequences what it can and cannot run on, and the margin for substitution is narrower than most people would believe, especially if they catch me on a monthly date night eating avocado toast, haha.

I always assumed this was a medical peculiarity, one more line item on the long list of ways my body operates differently from the standard model. Aged food makes me ill. Heavily cooked food gives me less than I need, and processed food gives me almost nothing at all. The fresher and more alive the food is when it reaches me, the better I function, and the further it has traveled from its living state, the worse I do, with a predictability that has never once failed to reproduce.

I stopped filing this under "medical anomaly" when I started reading the nutritional research on what actually happens to food as it ages, as it is processed, as it travels further from the living animal or plant that produced it. What the science describes is a measurable, reproducible loss of the very compounds my body depends on, replaced by inflammatory byproducts that accumulate in direct proportion to the time and distance between the food and its source. The pattern my body has been enforcing through consequences turns out to have a biochemical basis that most people never encounter, because most people's tolerances are wide enough to absorb the loss without noticing. Mine are not, and the research explains why.

What Happens When Food Gets Old

The word "fresh" is doing considerably more work than most people realize, and the science behind what happens when food ages is, I think, one of the most underappreciated chapters in nutritional research.

When meat sits, even under ideal refrigeration, a class of compounds called biogenic amines begins to accumulate through bacterial decarboxylation of the amino acids in the protein. Their names read like a roll call from a chemistry department that has seen too much: histamine, tyramine, putrescine, cadaverine. They are the natural byproducts of protein breaking down over time, and their concentrations rise predictably as the meat moves further from the moment of slaughter. Research published in PMC has established that the Biogenic Amine Index, which is the combined measurement of histamine, cadaverine, putrescine, and tyramine, should not exceed 5 milligrams per kilogram in fresh meat. A BAI between 20 and 50 milligrams per kilogram indicates poor quality, and anything above 50 conveys, in the researchers' own language, that quality is "very poor." Aged, fermented, and cured meat products routinely reach histamine levels of 249 milligrams per kilogram and tyramine levels exceeding 500, concentrations that would fail freshness testing by a factor of fifty.

The physical form of the meat looks unchanged at these levels. Color may even improve with certain aging techniques, because some of the chemical processes that produce biogenic amines also produce flavor compounds that the culinary world prizes in dry-aged steaks and charcuterie. What was nourishing inside the meat, however, has been quietly replaced by compounds that, in sensitive individuals, produce inflammatory cascading, headaches, blood pressure fluctuations, skin reactions including urticaria, gut inflammation, and in people with reduced diamine oxidase activity, severe systemic reactions that mimic full-spectrum allergic response. Diamine oxidase is the enzyme your body uses to break down histamine in the gut, and when it is insufficient or overwhelmed, even moderate amounts of aged food can produce reactions that most physicians will diagnose as food allergy when the real issue is that the food has been dead too long.

Cooking adds a second layer of loss. A study on vitamin B12 content in raw versus cooked beef, published in ScienceDirect, found that frying strips approximately 32 percent of the biologically active cobalamins from the meat, while roasting and grilling had comparatively little effect. Thiamine, one of the B vitamins critical for nervous system function and energy metabolism, often becomes undetectable after high-heat cooking, according to research on trace elements and B vitamins in raw and cooked meats. Riboflavin retention after cooking ranges from as low as 20 percent to a ceiling of about 58 percent depending on the cut, and niacin retention hovers between 30 and 51 percent.

The iron picture is even more striking, and it matters to me personally because I have been chronically anemic for most of my life despite eating red meat daily and supplementing with ferritin. Beef contains two forms of iron: heme iron, which is bound within the hemoglobin and myoglobin molecules of the muscle tissue and which the human body absorbs at roughly twice the efficiency of its counterpart, and non-heme iron, which is the less bioavailable form found in plant foods and in meat that has been thermally damaged. Research published in the Journal of Food Science and Nutrition demonstrated that heating meat to 80 degrees Celsius for two hours converts 62 percent of the heme iron into non-heme iron, effectively cutting the bioavailability of the most important mineral in the meat by more than half. Iron is still technically present. It is no longer in a form your body can use efficiently.

Raw food also contains natural enzymes, proteases and lipases among them, that assist in the digestion of the very nutrients the food provides. Heat deactivates these enzymes. What you gain in food safety from cooking, you pay for in the loss of the biological machinery that helps your body extract what it needs from the food in the first place.

Salt adds a third dimension to the problem, and this one is personal. I have been acutely salt-sensitive for as long as I can remember, in a way that goes well beyond the mild water retention or elevated blood pressure that most people associate with excess sodium. In my case, too much salt affects my nervous system and organs rapidly, noticeably, and with a severity that is disproportionate to the amount consumed. For most of my life I had no framework for understanding why, until I started reading the vascular research.

The science of what sodium does inside the body at the cellular level is, I think, one of the most startling chapters in cardiovascular research, and it connects to the question of freshness in ways that are not immediately obvious.

Every blood vessel in the human body is lined with a single layer of endothelial cells, and those cells are coated with a structure called the glycocalyx, a mesh of negatively charged biopolymers that functions as a barrier, a buffer, and a lubricant. Red blood cells are coated with their own glycocalyx, also negatively charged, and the repulsion between these two negative surfaces is what allows blood to flow frictionlessly through vessels that are, in some cases, narrower than the cells themselves. Research published in Pflügers Archiv demonstrated that the glycocalyx acts as sodium's first line of defense, buffering sodium ions within its negatively charged structure and preventing them from reaching the endothelial cell surface. When sodium levels remain within normal range, the system works. When they exceed the glycocalyx's buffering capacity, the damage begins.

A study by Oberleithner and colleagues found that sodium overload causes the endothelial glycocalyx to shrink by approximately 50 percent and stiffen by approximately 130 percent, with a 68 percent reduction in heparan sulfate residues, one of the key structural components of the barrier. A separate finding, published in the Proceedings of the National Academy of Sciences, demonstrated that a 5 percent increase in plasma sodium concentration stiffens endothelial cells by approximately 25 percent, leading to measurable cellular dysfunction. Research published in Frontiers in Physiology went further, demonstrating that elevated sodium renders endothelial cells "sticky" for red blood cells, because the excess sodium neutralizes the negative charges on both surfaces that normally keep them apart. When those charges are lost, red blood cells begin to adhere to the vessel walls, and the frictionless flow that healthy circulation depends on begins to break down.

The downstream effects cascade from there. Stiffened endothelial cells produce less nitric oxide, the molecule responsible for blood vessel dilation and healthy vascular tone. Reduced nitric oxide production increases oxidative stress. Oxidative stress activates inflammatory pathways, triggering production of pro-inflammatory cytokines including TNF-alpha, IL-1 beta, and IL-6. Research published in Frontiers in Physiology on the pathophysiology of salt-sensitive hypertension found that salt-sensitive individuals exhibit higher levels of circulating norepinephrine after a salt load than salt-resistant individuals, indicating that the sympathetic nervous system, the body's fight-or-flight wiring, remains activated in response to sodium in ways that it should not. The central nervous system itself detects changes in cerebrospinal fluid sodium concentration directly through specialized neurons in the brain, and in salt-sensitive individuals, this detection triggers a persistent increase in sympathetic nerve activity that drives blood pressure upward and keeps it there. Salt sensitivity affects an estimated 50 percent of hypertensive individuals and 25 percent of people with normal blood pressure, and despite decades of research, the precise mechanisms remain, in the words of multiple review papers, "incompletely understood."

My body has always operated at the far end of that sensitivity spectrum. I do not know the full reason, and the research confirms that the field does not either. What I know is that salt does something to my system that is rapid, measurable, and disproportionate, and what the science now shows is that sodium, at the cellular level, degrades the very structures that keep blood flowing, vessels flexible, and organs supplied with what they need. It strips the charge from the surfaces that depend on that charge to function. It stiffens what should be soft. It inflames what should be calm.

Here is the sentence I keep returning to: the physical form of the food remains, but the nourishment has been stripped away and replaced by something that either does nothing or actively harms.

Robert Kirk wrote that sentence in 1691, in different words, about a different subject entirely.

What the Folklore Already Knew

In The Secret Commonwealth, the Scottish minister Robert Kirk described how certain nonhuman peoples sustain themselves by feeding on what he called the "foyson or substance of Corns and Liquors," leaving the physical matter behind but stripping from it the vital essence that makes it nourishing. Kirk was writing about the faeries of the Scottish Highlands, and his use of the Scots word foyson, which the Oxford English Dictionary defines as "inherent vigour or vitality" and "power, strength, capacity" and marks as surviving chiefly in Scottish English, was deliberate and precise. He was not describing theft of physical food. He was describing the extraction of the life from the food while leaving the husk intact. The Gaelic equivalent, toradh, carries the same meaning, translated as "profit" or "fruit" in Irish Gaelic, referring not to the physical substance of the food but to its hidden spiritual and nutritive essence.

The folklorist Katharine Briggs confirmed the concept through both Kirk and the Highland collector J. G. Campbell, writing in An Encyclopedia of Fairies that the faeries "steal the essential good out of human food, and leave an unnourishing substance behind them." Briggs used the English word "goodness" as a synonym for foyson and toradh, which is telling, because goodness is exactly the word that a modern speaker would use to describe what biogenic amine accumulation, thermal degradation, and oxidative nutrient loss take from food as it ages and is processed.

What the faeries prefer to eat, across every tradition that documents their dietary habits, is fresh dairy and fresh grain, with an emphasis on freshness that reads less like preference and more like biological necessity. In Ireland, the first portion of every batch of churned butter was left for the fae. Across the Scottish Isles, a bowl of cream or fresh milk was set on the windowsill or doorstep, and it was considered essential never to watch the faeries come for it. In Cornwall, spilled milk was regarded as a gift to the faeries, and scolding a child who spilled it was strongly discouraged, a tradition so widespread that it may be the actual origin of the phrase "don't cry over spilled milk." The Danish house spirit known as the Nis demanded porridge with fresh butter and was said to fly into a destructive rage if the butter was missing or had been replaced with an inferior substitute. In Malaysian folklore, the Bajang, a spirit sometimes kept as a familiar, requires eggs and fresh milk as sustenance. Even in John Milton's 1645 poem L'Allegro, Faery Mab is described eating junkets, a dessert of fresh cream and rennet, and Ben Jonson's 1605 play Entertainment at Althorp describes how the faerie mistress "liked to rob the dairy."

The consistency across unrelated cultures is, I think, remarkable enough on its own, but the detail that moves me from observation to hypothesis is the salt.

The Salt Problem

A Manx woman walking on the road heard music, followed the sound, and encountered a group of faeries she could hear but not see. They asked what she carried in her basket. She offered bread. They accepted, but only after confirming that there was no salt in the mix. In Scottish tradition, oatcakes hung above a cottage threshold would protect a mother and newborn, and burning an oatcake would drive off the faeries, but the bread itself was a gift they valued deeply, provided the salt had been left out. A Cumbrian farmer, annoyed that faeries had been sampling milk he'd left cooling outside his cottage overnight, threw salt into the churn. When the faeries tasted the salted milk, they spat it across his entire property, and wherever the salty milk landed, the grass died and would not regrow.

Salt is one of the two primary wards against nonhuman peoples in European folklore, the other being iron. Spreading salt across a threshold kept the fae from entering. Sprinkling salt on food being carried to farmhands in the fields was explicitly said to prevent faeries from "extracting the nourishment from it unseen." Katharine Briggs argued that salt is abhorrent to the Good Neighbours because it is "a universal symbol of preservation, eternity and of goodwill."

I think Briggs identified the right quality but may not have traced it far enough, because preservation is, at the biochemical level, the precise opposite of what foyson requires.

Salt halts enzymatic activity. It inhibits the microbial metabolism that keeps organic matter in its living state. It draws moisture from cells through osmosis, collapsing the very structures that contain and transport nutrients. It locks food into a state of chemical stasis in which the form endures, sometimes for years, while the biological activity that made the food nourishing ceases entirely. A salted fish looks like a fish. A cured ham looks like meat. The appearance is preserved with remarkable fidelity, and what has been lost is invisible, because what has been lost is the foyson.

The folklore knew this, I think, because salt is the opposite of foyson. It is the chemical enforcement of stillness on matter that was meant to be consumed while it was still moving, still enzymatically active, still carrying its charge. No wonder the faeries will not touch it. No wonder they check the bread before they eat it. They are not being difficult, they are checking whether the food is still alive.

What Comes Next

This is the second piece in what I now expect to be a longer series. The first, "Faerie Well Then!," laid the groundwork for foyson as a concept and introduced the Bio-Well scan data that documented an unusual pattern in energy absorption. This piece has, I hope, established that the concept of foyson is not merely folkloric but maps onto verifiable biochemical processes that modern nutritional science has documented in detail without ever using the word. The physical form of the food remains, the nourishment departs, and what replaces it is measurably harmful. Kirk knew. Briggs knew. The women who left fresh cream on the windowsill and checked the bread for salt before offering it knew. The science is arriving at the same destination through a different door.

The next piece in this series will ask a question that the research has been circling for some time now: why the cow? Why is this one animal, above all others, the one that virtually every ancient civilization on earth venerated as sacred, and why are its products, specifically, the offerings that the folklore says the faeries demand? I think the answer lives in foyson, and I think the implications extend into territory that most researchers in this field have not yet been willing to enter.

Stay close. There is more to come..