In one pass Whether a molecule is safe depends on what it is, how much of it you take in, and how fast your body clears it, not on whether the label says added.
Educational content, not medical advice — consult a clinician.
Whether a molecule is safe depends on what it is, how much of it you take in, and how fast your body clears it, not on whether the label says added. The bit of nitrite in cured pork is an example: it is holding back a bacterium that can stop a person breathing.
The bacterium is Clostridium botulinum. Its spores are everywhere, in soil and on the surface of meat, and they usually lie quiet. It hates oxygen, and cured meat is exactly the home it likes: no oxygen, moist, room temperature, plenty of protein. Once the spores wake up, they release a nerve toxin into the meat. The toxin jams the switch that nerves use to signal muscles: first the eyelids cannot stay up and speech slurs, then the paralysis moves down to the breathing muscles. If these symptoms, or blurred vision or trouble swallowing, follow homemade cured meat, canned food or fermented food, go to the emergency department immediately.
Nitrite slows the growth of the bacterium and delays the production of its toxin; it also fixes that pink color. Take it out and you do not get cleaner meat; you reopen the door to botulism. So the real choice is never additives or no additives; it is which risk is smaller and easier to control. How the body clears a molecule dose by dose is covered in the chapter Why the dose makes the poison.
Safety · The risk nitrite carries itself
Nitrite is not innocent either. In the meat and in your stomach it can take part in forming nitrosamines, which is one of the proposed mechanisms behind the International Agency for Research on Cancer (IARC) classifying processed meat as a Group 1 carcinogen. Group 1 means sufficient evidence that it causes cancer in people: it describes how certain the evidence is, not how large the risk is. The grading and the risk figures are covered properly in Processed Meat, so they are not repeated here.
So the real approach is not a choice between allow and ban. It squeezes the dose into the narrow gap where there is just enough to hold back the bacterium while as little nitrosamine as possible forms. After re-evaluating it in 2017, the European Food Safety Authority (EFSA) set the acceptable daily intake (ADI, the amount you could eat every day for a lifetime with no appreciable expected risk) for nitrite ion at 0.07 mg per kg of body weight.
One more thing worth noticing, and the chapter Your body cannot read the label comes back to it: cured meats labeled no nitrite added often use cultured celery powder instead. Celery is naturally rich in nitrate (vegetables are the main dietary source of nitrate, EFSA 2008), and a bacterial culture reduces it to nitrite. The industry line is blunt: nitrite is nitrite, wherever it comes from (Mermelstein 2018). In other words, the label changed and the molecule did not, and the bacterium reads the molecule.
bouvard-2015-iarc-red-meat
Chapter 2
Why the dose makes the poison
The same molecule is harmless in a small amount and deadly in a large one, and there is no magic in between. The only difference is whether you clear it as fast as it comes in.
A foreign molecule in your blood has only two exits: the kidney filters it into urine, or the liver dumps it into bile and it leaves with stool. The trouble is that most foreign molecules are fat-loving: they dissolve in oil, so they can slip through cell membranes. The kidney tubule works to filter one into urine, and it dissolves straight back through the tubule wall into the blood. Filtered out, back in, again and again: the kidney alone can never get rid of it.
So the liver reshapes it first, in two steps that cannot be swapped. Step one drills a handle: a large family of enzymes in liver cells (cytochrome P450, often written CYP450) attaches an oxygen atom to the molecule, creating a connection point. Step two welds on a water balloon: another group of enzymes hangs a large, water-loving, charged tag on that handle.
With the tag on, its character changes: heavier, charged and water-loving, it can no longer slip back through membranes, and once the kidney filters it, it can only leave in urine. That is all detoxification is: not destroying the molecule, but reshaping it into something that can leave.
And this production line has a limited number of enzymes, each with a top speed. Once it saturates, whatever arrives next piles up. That one fact is the whole reason the dose makes the poison.
Mechanism · step one sometimes makes things worse
Honestly: drilling the handle is done by oxidation, and the intermediate that oxidation produces is often far more reactive than the original molecule. Almost always, step two seals it immediately and nothing happens. But if step one runs too fast and step two cannot keep up, that reactive intermediate gets a window in which to crash into things.
Aflatoxin takes exactly this road to cause cancer: it arrives at the liver fairly harmless, and it is the liver's own enzymes that activate it into a highly reactive molecule, which then lodges itself into DNA (IARC 2012). The human liver is also weak at step two for this molecule, so step one does not need to run too fast: even a tiny amount sends some of it into DNA, which is why regulators set no tolerable daily intake for aflatoxin and ask only for as little as possible. The chapter Is natural always safe meets it again.
For the whole reshaping system, the liver half: see Hepatic System; the kidney half: see Renal System. For how powerless detox products are against it, see Detox & Cleanse.
Numbers · almost nothing happens before saturation
Enzymes are physical objects: finite in number, each with a ceiling on how fast it can work.
At low amounts there are idle enzymes to spare. Whatever arrives is grabbed immediately. Clearance speed tracks concentration — double the concentration, double the clearance rate. The result is that a fixed fraction leaves every hour, and it can never pile up.Past a certain amount, every enzyme is occupied. The production line is at capacity. More arriving changes nothing: only a fixed quantity can be cleared per hour.Beyond that point, input exceeds capacity and the remainder starts queuing. Blood concentration climbs, and the reactive intermediate that should have been sealed instantly now has time to linger. So the relationship between dose and harm is not a straight slope. It is a hinge: almost nothing happens below saturation, and it rises steeply above it. Is this molecule toxic is therefore the wrong question. The question is: does this amount exceed the speed at which my body clears it?
Mechanism · A hard limit at one end, none at the other
Alcohol is the easiest to grasp: the enzyme that breaks it down saturates at a very low concentration. So blood alcohol does not fade proportionally — a fixed amount disappears per hour. That is also why drinking twice as much does not take twice as long, but longer. For the detail, see Alcohol Metabolism.
Vitamin C is the other end. However much you take, the transporters in your intestinal wall are finite in number, so the absorbed fraction actually falls; and of whatever does reach your blood, anything above a certain concentration gets tipped straight into the urine by the kidney (Levine 1996). Which is why, when the EU re-evaluated ascorbic acid (E300 — vitamin C), it set no acceptable daily intake at all: at normal dietary levels it is regarded as physiologically harmless (EFSA 2015).
The same logic yields a strict limit at one end and no limit at all at the other. And what decides the outcome is never whether the molecule is natural or synthetic. It is how fast your body clears it.
Numbers · Where the 100 comes from
How much of an additive is allowed follows a short algorithm. Run long-term feeding studies, escalating the dose until you find the boundary where measurable abnormalities begin. The tier just below it is the no-observed-adverse-effect level (NOAEL). Divide that by 100 and you have the acceptable daily intake (ADI), in milligrams per kilogram of body weight per day.
The 100 is two tens multiplied. What's worth seeing clearly is that each of those tens corresponds to the very machine this chapter has been describing (WHO/FAO 2009):
The first 10 · you are not a rat. The enzyme set in a rat's liver is not yours, and the same molecule can be cleared at speeds an order of magnitude apart in the two species.The second 10 · you are not the average person either. Among humans, how much of each liver enzyme you carry is set by your genes; a child's production line isn't finished; the elderly and people with poor liver function have less capacity. That spread also reaches an order of magnitude. So the 100 isn't administrative caution. It is the quantified margin for one specific thing: how much clearance speed can differ. The arithmetic belongs to a committee. The reasoning belongs to your liver and kidneys.
The ADI's definition rewards slow reading too: eating this much every day for a lifetime is expected to carry no appreciable health risk. It is not a red line where harm begins; it is a floor below which a lifetime of daily intake is fine. Concretely: the ADI for aspartame is 40 mg per kg of body weight (JECFA 2023). By JECFA's own arithmetic, if a can of diet soda contains 200-300 mg of aspartame, a 70 kg adult would have to drink more than 9-14 cans a day to go over it, and that assumes no other source. The same year, the International Agency for Research on Cancer (IARC) placed aspartame in Group 2B (possibly carcinogenic), on limited evidence; that grade describes how certain the evidence is, not how large the risk is, and JECFA kept the ADI after reviewing it. Each sweetener's ADI, and the full story behind that headline, are in Artificial & Non-nutritive Sweeteners.
And the thinnest link in the framework, stated honestly: it assesses each substance separately, and handles the combined effect of many additives eaten together far less solidly than any one of them alone. Put that back into the mechanism of this chapter and you can see why the combination is hard to compute: different molecules may crowd onto the same production line. Compete for the same enzyme family and together they might push it to saturation, while individually not one of them exceeded its limit. This gap is often pointed out and is still being worked on. It is not evidence that additives are toxic, but it is genuinely the weakest link as things stand.
The routine test for protein in milk never sees protein at all. It counts nitrogen atoms, then does one multiplication.
When you drink a mouthful of milk, what your body actually takes is not the word protein. A protein is a long chain. In the stomach and small intestine, enzymes that work like scissors cut it into pieces, and carriers in the wall of the small intestine move the amino acids into the blood one by one.
Every amino acid carries a head that contains nitrogen. That is where the multiplication comes from: nitrogen makes up about 16% of the weight of protein, so the test measures total nitrogen, multiplies by about 6.25, and calls the result protein. The conversion rests on a single assumption: that all the nitrogen in the sample sits on amino acids.
Melamine exploits exactly that assumption. It is an industrial raw material for plastics and coatings: a small molecule packed with nitrogen, two thirds nitrogen by weight. Sprinkle some into watered-down milk and the nitrogen figure comes right back, and the protein on the lab sheet looks good again.
But what the instrument reads and what the baby receives have nothing to do with each other. Melamine is not an amino acid: the scissors in the stomach have nowhere to cut, the carriers in the small intestine do not recognize its shape, and not a single amino acid gets carried in. The number is real; the thing it stands for is not there, not one gram of it.
And where it goes next is the kidney.
Mechanism · the kidney concentrated it into a stone
Melamine does not need to trouble the liver: it is already water-loving enough that the kidney can filter it straight into urine, no handle required. That sounds like good news. It is exactly where the trouble is.
The kidney tubule's day job is taking water back. As filtrate runs down the tube, water is drawn back into the blood and the remaining fluid gets steadily more concentrated. So the melamine gets steadily more concentrated too. And the same industrial feedstock often carries a relative alongside it — cyanuric acid, which travels the same route.
Once melamine and a partner molecule traveling the same route (cyanuric acid, or the uric acid the body already makes) are concentrated enough inside the tubule, they begin to interlock: the hydrogen of one against the nitrogen of the other, layer on layer, into a crystal that will not dissolve in water (WHO 2008). What is now in the tube is no longer a molecule. It is a stone. The tube blocks, urine cannot get out, pressure backs up, and filtration stops.
Look closely at the causation here: the harm is not toxicity in the poisoning sense. It is physical obstruction. And it was the kidney doing its job that concentrated it into existence — the very act that turns a low-toxicity molecule into a stone is what this organ does all day.
That also explains why it was infants who collapsed: their tubes are narrower, their urine more concentrated, and formula was their only food — per kilogram of body weight, more went in than for any adult. In the 2008 incident WHO counted roughly 300,000 cases, 51,900 hospitalizations, and 6 deaths (WHO 2008).
Evidence · That 6.25 is a proxy
An instrument often does not measure the thing you care about itself. It measures a proxy — a shadow that usually moves in step with the thing you care about. Break that 'usually' deliberately and the number survives while its meaning does not.
This tool is portable. Amino-acid spiking in the protein-powder trade is the second generation of the same move: cheap free amino acids — glycine, taurine — are blended into the powder. This time what is added really is amino acids, so the nitrogen passes easily. But they happen to be the ones your body can already build itself, and you get no more of the ones you actually lack. The nitrogen test still cannot tell the difference, because it was never measuring what you wanted in the first place.
So the next time you see any number, it is worth asking first: is the thing this instrument directly measured the same as the thing I care about? And if there is a conversion in between, what does that conversion assume?
Myth · melamine was never a food additive
Melamine is not a food additive. It was never approved as one, never evaluated as one, and nobody ever gave it an acceptable daily intake. So the melamine scandal proves additives are not safe is broken grammatically, not politically: it is equivalent to saying someone robbed a bank with counterfeit notes, therefore currency is unsafe.
Conflating the two actively helps the counterfeiters. Your vigilance gets spent on the long chemical names on the ingredient list, while the thing you actually need to guard against is not on that list at all — the ingredient list is filled in by the people who follow the rules.
Background · Two lists: permitted and forbidden
On paper the cut is clean, and it uses two entirely separate lists. The permitted list is GB 2760, the Standard for Uses of Food Additives, where each entry is pinned down: its name, which food categories it may enter, the maximum level (GB 2760-2024). The forbidden list is the Catalogue of Non-Food Substances That May Be Illegally Added to Food, published by the Ministry of Health in batches from December 2008; melamine is on it, and so is Sudan red. Their category name is 'non-food substances'.
Sudan red is the same sentence in another form: an industrial dye for shoe polish and floor wax, mixed into chilli powder only because chilli powder is priced on redness (EC 2005/402). It shares one feature with melamine, and that feature says more than the lists do — neither was added to make the food better. Both were added to make a number or a look better. That is the real definition of an illegal additive: it serves the instrument and the shelf, not the person eating it.
WHO later set a tolerable daily intake for melamine of 0.2 mg per kg of body weight (WHO 2008). The point of that number isn't to permit adding it. It draws a line for trace contamination — migration from plastic containers, say — so that deliberate adulteration and trace contamination can be told apart.
Tetrodotoxin, the pufferfish toxin, is 100% natural and contains no additives, and a small mouthful can stop a person breathing within hours.
This chapter does one thing: it pulls the words natural and safe apart. Three examples, none with any man-made ingredient.
Tetrodotoxin plugs, with precision, the small door in nerve-cell membranes that lets sodium ions in and out. With the door blocked, nerves cannot fire electrical signals and muscles get no instructions: first the lips and tongue go numb, then the paralysis spreads all the way to the breathing muscles.
Aflatoxin is what grows on peanuts, corn and nuts when they get damp and moldy. It takes exactly the road described in the chapter Why the dose makes the poison: liver enzymes drill a handle onto it, the intermediate they make is highly unstable, and before step two can seal it off, it has already driven into DNA and stuck there.
Bongkrekic acid hides in wood ear mushrooms soaked too long, homemade fermented corn flour and spoiled wet rice noodles. It gets into your mitochondria and jams the cell's energy machine; cells left without fuel die in large numbers.
If your lips and tongue go numb after eating pufferfish, or you vomit, have belly pain, feel dizzy or weak after eating wood ear soaked too long or spoiled wet rice noodles, go to the emergency department now and tell the doctor what you ate.
All three survive cooking, and none has an antidote. Natural describes where something comes from, not whether it is safe: many of the most toxic molecules are made by living things, and they were made in the first place to kill something else.
Safety · Key facts on three natural toxins
Tetrodotoxin does not cook out: ordinary heat will not destroy it. And there is no antidote: all a hospital can do is breathe for you with a machine while your body metabolizes it.
Aflatoxin, once lodged in DNA, damages p53, the gene that acts as a brake. IARC lists it as Group 1, meaning sufficient evidence that it causes cancer in people, the same group as processed meat and tobacco; the grouping describes how certain the evidence is, not that the three carry the same risk. It is heat-stable too; frying will not remove it.
Bongkrekic acid is released by a bacterium called Burkholderia gladioli in soaked Wood Ear Mushroom fungus and wet rice noodles. Among the poisonings recorded in China between 2010 and 2020, the case fatality rate approached one in three. Heat-stable, and no antidote. How to avoid natural toxins is covered on the Foodborne Illness page.
Mechanism · What no antidote really means
Notice what these three share: no antidote means there is no clearance route anyone can speed up. All a hospital can do is keep you going while your body's own clearance machine slowly grinds through it. The rule that the dose makes the poison still holds for them; it is just that a tiny amount is enough to kill.
And synthetic likewise only describes origin: the vitamin C you take as a supplement, whether pressed from a fresh pepper or made in a factory, is the same molecule by the time it reaches your small intestine, and the transport protein in the intestinal wall cannot tell them apart and does not care.
Honestly: natural things are on average more worth eating is often true. But it is true because whole foods arrive with fiber, potassium, and phytochemicals attached — not because the word natural holds any magic. The reason has to match the conclusion, or the next person selling a pure natural detox herb will win you over with the identical sentence.
Chapter 5
The real issue is oil, salt and sugar
The real problem with a bag of chips is not the chemical names at the end of the ingredient list. It is the things at the very front: oil, salt and sugar.
Ingredients are listed from most to least. What this bag does to you is decided by the top three, not by the antioxidant at the end that makes up a few parts per thousand.
How processed a food is and whether it contains additives are two different things. They often show up together, so they keep being treated as one:
A sugary drink can have zero added preservatives and still deliver thirty-some grams of sugar in one bottle.A soy sauce labeled zero added can have exactly as much sodium as the ordinary bottle next to it.Plain yogurt, canned tomatoes and frozen vegetables all list additives, and they are all good foods. Ultra-processed food really is a problem, and that is not a claim this story takes apart. The key is why: in an inpatient trial with nutrients broadly matched, people still ate more, and the clues point to what the food had been turned into, such as more calories in each bite, a soft texture that is easy to chew, and fast eating. On current evidence, additives look more like a marker of ultra-processed food than the main cause.
Mistaking the marker for the cause has a real cost: you pick a box of zero-added cookies, eat the same sugar and oil, and, because the label reassures you, quite possibly eat a little more.
Evidence · How far the case on ultra-processed food goes
Ultra-processed food really is a problem. That is not a claim this story sets out to take apart; it has evidence.
In the Hall 2019 inpatient crossover trial, the two diets were matched as served for calories, macronutrients, sugar, sodium and fiber, and people could eat as much as they liked. During the ultra-processed weeks they ate about 500 kcal more a day, and their weight went up. It shows that, in the short term, eating this way makes people eat more without noticing; but it was very small, each diet lasted only two weeks, and it cannot tell which property of the food was doing most of the work.
An umbrella review (a review that pools many ) found that people who eat more ultra-processed food have more of a range of adverse outcomes (Lane 2024). These are observed associations and cannot show on their own that the food is the cause; what Hall's trial adds is causal evidence for one link, eating more.
As for additives themselves: a few emulsifiers have disturbed the gut bacteria in mouse experiments, which has not been confirmed in people. The NOVA system, this trial and the emulsifier question are all covered in detail in Ultra-processed Foods (UPF).
In practice · Where to look on the package
Look first at the nutrition table: energy, sodium, sugar. Those numbers are what you actually accumulate day after day (from March 2027 sugar and saturated fat become mandatory entries too, GB 28050-2025).Then read the top three ingredients. If sugar or refined oil is first, nothing further down the list changes that.Don't spend your energy decoding the chemical names at the end. Ascorbic acid is vitamin C — a legal additive numbered E300 in the EU, used as an antioxidant, and the same molecule you get from an orange. After re-evaluation the EU didn't even set an ADI for it, since at normal dietary levels it is regarded as physiologically harmless (EFSA 2015). A chemical name you don't recognize tells you that chemical nomenclature and everyday speech are different vocabularies. It tells you nothing else. Why sodium and sugar earn that attention is covered in see Salt (Sodium) and in Sugar & Honey; the randomized evidence on sodium and blood pressure is the DASH-Sodium trial (Sacks 2001), and the ceiling on free sugars is WHO's recommendation (WHO 2015).
No part of your body can tell whether a molecule is natural or synthetic. This is not hair-splitting; it is a matter of structure: a molecule has no field for that.
When a molecule arrives at the wall of the small intestine, only two kinds of things are waiting for it: carriers that recognize shapes, and enzymes that recognize shapes. They work in a very physical way, like a lock reading the teeth of a key: whether it gets carried in, and whether it gets cut, depends on what it looks like, not on where it came from.
Vitamin C is the cleanest example. Ascorbic acid pressed from a fresh pepper and ascorbic acid made in a factory are the same molecule, with the same atoms in the same arrangement. The carrier in the intestinal wall treats the two exactly alike, because it cannot do otherwise: all it can feel is the shape of the teeth, and the teeth are identical.
So the body reads only three things: what the molecule looks like, which decides which locks it can open; how much arrives, and how fast, which decides whether it outruns your clearance; and what it came with, since the fiber, water and potassium in a whole food change how fast it is absorbed.
Natural and synthetic are not on that list. Those words describe a molecule's history, and the body never checks history. So zero added promises a category that does not exist inside you.
A CLOSER LOOK
Transporters recognize shape, not origin
Identical atoms and arrangement make ascorbic acid identical to an intestinal transporter.
1The same key shape
This compares the same ascorbic-acid molecule, not the complete composition of two foods.
2Dose and food context still matter
Amount, arrival rate, and accompanying fiber, water and nutrients still matter. Natural or synthetic labels cannot replace that information.
Illustration for understanding; not to scale. Saved figures include explanations and sources.
Mechanism · the label changed; the molecule did not
For how concrete that is, the cured-meat example is enough. A cured meat labeled no nitrite added has often switched to cultured celery powder. Celery is naturally rich in nitrate (vegetables are the main dietary source of nitrate, EFSA 2008), and a bacterial culture reduces it to nitrite.
So: what lands on the botulism bacterium's enzymes is the same nitrite ion; and what takes part in forming nitrosamines in your stomach is the same nitrite ion. The industry line is blunt: nitrite is nitrite regardless of the source (Mermelstein 2018).
The label changed; the molecule did not. The bacterium cannot read the label, and neither can your stomach.
Myth · what the phrase is actually selling
It is selling a contrast that does not exist. This product has zero added preservatives implies the others added them, and the others are worse. But the preservative the others use has been evaluated, numbered, and capped; whereas this so-called zero-added version may simply have a shorter shelf life (so the door to botulism opens a crack again), or may just have switched to a molecule that does not count as an additive on the label and is identical inside your body. You paid more and bought reassurance, not safety.
Regulators have seen this too: from March 2027, claims like zero added may no longer be printed on prepackaged food in China (GB 7718-2025). But that only takes the words off the shelf. What actually protects you is knowing why they never promised anything in the first place.
Myth · Which line of reasoning is wrong
This page is not a brief for the food industry:
Ultra-processed food is a real problem, and the real problem is the recipe and the structure; see the chapter The real issue is oil, salt and sugar.The sugar and sodium in the recipe are a real problem, and those two numbers are printed plainly on the nutrition table.People really do put things into food that do not belong there, and those things appear on no ingredient list at all; see the chapter How melamine fooled the protein test. All of that vigilance is warranted. What needs dismantling is the bad reasoning: chemical name equals danger, natural equals safe, contains additives equals toxic. Its flaw is not excess vigilance — it is vigilance aimed at the one dimension the body does not read, a molecule's origin, and therefore missing the three it does: which molecule, how much, and what it came with.
Next time you see those words on a package, you do not need to remember a single regulation. One question is enough: did the molecule change, or only its origin story?
Related: the closest precedent is — see MSG / Glutamate; whether organic food is actually safer is at Organic Food.
References · 18
Sofos, J. N., Busta, F. F., & Allen, C. E. (1979). Botulism control by nitrite and sorbate in cured meats: A review. Journal of Food Protection, 42(9), 739-770. At suitable concentrations nitrite retards Clostridium botulinum growth and delays production of its neurotoxin. 10.4315/0362-028X-42.9.739
EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS). (2017). Re-evaluation of potassium nitrite (E 249) and sodium nitrite (E 250) as food additives. EFSA Journal, 15(6), 4786. Derived an ADI of 0.07 mg nitrite ion/kg bw per day based on increased methaemoglobin. 10.2903/j.efsa.2017.4786
Guengerich, F. P. (2008). Cytochrome P450 and chemical toxicology. Chemical Research in Toxicology, 21(1), 70–83. 10.1021/tx700079z
EFSA Panel on Contaminants in the Food Chain (CONTAM), Schrenk, D., Bignami, M., Bodin, L., Chipman, J. K., del Mazo, J., Grasl-Kraupp, B., Hogstrand, C., Hoogenboom, L., Leblanc, J.-C., Nebbia, C. S., Nielsen, E., Ntzani, E., Petersen, A., Sand, S., Schwerdtle, T., Vleminckx, C., Marko, D., Oswald, I. P., Piersma, A., Routledge, M., Schlatter, J., Baert, K., Gergelova, P., & Wallace, H. (2020). Risk assessment of aflatoxins in food. EFSA Journal, 18(3), e06040. DNA adduct formation rises linearly from very low doses (a linear non-threshold model); liver GST activity toward the activated epoxide is much lower in humans than in resistant mice; because aflatoxins are genotoxic carcinogens, no tolerable daily intake is set and exposure should be as low as reasonably achievable. 10.2903/j.efsa.2020.6040
Jancova, P., Anzenbacher, P., & Anzenbacherova, E. (2010). Phase II drug metabolizing enzymes. Biomedical Papers, 154(2), 103–116. 10.5507/bp.2010.017
Levine, M., et al. (1996). Vitamin C pharmacokinetics in healthy volunteers: evidence for a recommended dietary allowance. PNAS, 93(8), 3704–3709. In-hospital depletion-repletion study of 7 healthy volunteers (4-6 months on a diet with less than 5 mg/day), seven daily doses from 30 to 2500 mg. Bioavailability was complete for a 200 mg single dose; at single doses of 500 mg and higher bioavailability declined and the absorbed amount was excreted; plasma saturated at 1000 mg daily, white cells at 100 mg. The abstract gives no absorption percentage for 500 or 1250 mg (abstract, PMID 8623000). 10.1073/pnas.93.8.3704
EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS). (2015). Scientific opinion on the re-evaluation of ascorbic acid (E 300), sodium ascorbate (E 301) and calcium ascorbate (E 302) as food additives. EFSA Journal, 13(5), 4087. No ADI was established, as ascorbic acid and its salts are regarded as physiologically harmless at typical dietary intake levels. 10.2903/j.efsa.2015.4087
Gossner, C. M., Schlundt, J., Ben Embarek, P., Hird, S., Lo-Fo-Wong, D., Beltran, J. J. O., et al. (2009). The melamine incident: Implications for international food and feed safety. Environmental Health Perspectives, 117(12), 1803-1808. Melamine was deliberately added to diluted raw milk to inflate apparent protein content, because routine testing measures nitrogen, not protein; about 300,000 Chinese infants and young children were affected. 10.1289/ehp.0900949
World Health Organization. (2008). Toxicological and health aspects of melamine and cyanuric acid: Report of a WHO Expert Meeting, Ottawa. Established a tolerable daily intake for melamine of 0.2 mg/kg body weight. WHO reported 294,000 cases, 51,900 hospitalizations, and 6 deaths as of 1 December 2008. www.who.int/news/item/05-12-2008-experts-set-tolerable-level-for-melamine-intake
Lago, J., Rodriguez, L. P., Blanco, L., Vieites, J. M., & Cabado, A. G. (2015). Tetrodotoxin, an extremely potent marine neurotoxin: Distribution, toxicity, origin and therapeutical uses. Marine Drugs, 13(10), 6384-6406. TTX blocks fast voltage-gated sodium channels causing paralysis and respiratory failure; it is not destroyed by conventional cooking heat, and no specific antidote exists. 10.3390/md13106384
Zhang, H., Guo, Y., Chen, L., Liu, Z., Liang, J., Shi, M., et al. (2023). Epidemiology of foodborne bongkrekic acid poisoning outbreaks in China, 2010 to 2020. PLOS ONE, 18(1), e0279957. 19 outbreaks, 146 illnesses, 43 deaths; CFR 29.5%; 79.0% occurred at home; Auricularia auricula 3/5 deaths (60%). 10.1371/journal.pone.0279957
Hall, K. D., Ayuketah, A., Brychta, R., Cai, H., Cassimatis, T., Chen, K. Y., et al. (2019). Ultra-processed diets cause excess calorie intake and weight gain: an inpatient randomized controlled trial of ad libitum food intake. Cell Metabolism, 30(1), 67-77.e3. 20 inpatients, 2 weeks per diet, crossover. Meal eating rate was greater on the ultra-processed diet by 17 +/- 1 kcal/min (7.4 +/- 0.9 g/min), p < 0.0001 - that is the between-diet difference; ratings of pleasantness and familiarity did not differ (full text, PMC7946062). Diets were matched for presented calories, energy density including beverages (1.024 vs 1.028 kcal/g), macronutrients, sugar, sodium and fiber (21.3 vs 20.7 g/1000 kcal, partly via fiber supplements added to ultra-processed meals); non-beverage energy density was 1.957 vs 1.057 kcal/g (~85% higher), which the authors say likely contributed. Intake was 508 +/- 106 kcal/day greater on the ultra-processed diet (full text, Table 1 and Results). 10.1016/j.cmet.2019.05.008
Lane, M. M., Gamage, E., Du, S., Ashtree, D. N., McGuinness, A. J., Gauci, S., et al. (2024). Ultra-processed food exposure and adverse health outcomes: umbrella review of epidemiological meta-analyses. BMJ, 384, e077310. Umbrella review of 45 pooled analyses (about 9.9 million people): direct associations for 32 (71%) outcomes. Class I (convincing): cardiovascular disease mortality RR 1.50 (1.37-1.63; GRADE very low), type 2 diabetes dose-response RR 1.12 (1.11-1.13; moderate), prevalent anxiety OR 1.48 and common mental disorders OR 1.53 (low). Class II: all-cause mortality RR 1.21 (1.15-1.27; low), heart disease mortality HR 1.66, type 2 diabetes OR 1.40 (very low), depression HR 1.22, adverse sleep outcomes OR 1.41, wheezing RR 1.40 and obesity OR 1.55 (all low). Overall 22 pooled analyses were low quality, 19 very low and 4 moderate; all observational (abstract, PMID 38418082). 10.1136/bmj-2023-077310
Monteiro, C. A., Cannon, G., Levy, R. B., Moubarac, J. C., Louzada, M. L. C., Rauber, F., et al. (2019). Ultra-processed foods: what they are and how to identify them. Public Health Nutrition, 22(5), 936-941. 10.1017/S1368980018003762
EFSA Panel on Contaminants in the Food Chain. (2008). Nitrate in vegetables — scientific opinion. EFSA Journal, 6(6), 689. Leafy vegetables (including spinach) are major dietary nitrate sources; dietary nitrate from vegetables is part of the nitrate-nitrite-nitric-oxide pathway. 10.2903/j.efsa.2008.689
National Health Commission & State Administration for Market Regulation of the PRC. (2025). National food safety standard: General rules for the labelling of prepackaged foods (GB 7718-2025). Issued 2025-03-16, effective 2027-03-16. Prohibits no-added and zero-added claims and their synonyms; no-content claims remain permitted only where the component is genuinely 0 or below the method's detection limit. www.news.cn/politics/20250327/9360e28149a44e4898de8ece0305fc6c/c.html