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The additive playbook

Most of the 10,000+ substances allowed in U.S. food are inert. About forty matter — and a regulatory loophole means roughly nobody is checking the rest.

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The additive playbook

TL;DR. U.S. food law allows about 10,000 added items. Another 1,000 sit in food the FDA has never seen. About 40 matter. The rules fit on one page: GRAS, FDA, EFSA, 7 groups, a 1 to 5 concern score. The short watchlist: sodium nitrite, a few emulsifiers, most coal-tar dyes, the old man-made preservatives, and the artificial sweeteners. Most scary names on a label (xanthan, lecithin, citric acid) are fine. Knowing the difference is the skill.

What you'll learn

  • What "GRAS" means, and why about 98.7% of new additives since 2000 never crossed an FDA desk.
  • How EFSA, JECFA, and FEMA split the rule-making map, and why the EU bans things the U.S. allows.
  • The 7 main additive groups with named examples.
  • The short list of additives GoodEnough scores at concern level 4 or 5, and why.
  • Which additives flag a NOVA-4 product but cause no direct harm.
  • How GoodEnough's two-axis ingredient score works.

The GRAS framework

An additive is any substance added to food. The 1958 Food Additives Amendment said new ones needed FDA testing before sale. It made one exception: items scientists already agreed were safe (salt, vinegar) skipped review. That exception is Generally Recognized As Safe, or GRAS. Congress wrote it for a few dozen basic items.

In 1997 the FDA built a voluntary notification path. A company could hire its own experts, call a substance GRAS, ship it in food, and never tell the FDA. Filing was a choice. Chris van Tulleken worked with EDF's Tom Neltner and Maricel Maffini and found the result: 756 of 766 new food substances added between 2000 and 2010 (about 98.7%) were self-declared GRAS by the company selling them. EDF says about 1,000 substances now sit in U.S. food without the FDA knowing. Harvard's Food Law and Policy Clinic called U.S. food-additive rules "essentially voluntary."

Flavorings get worse. About 2,600 of them are GRAS-certified by FEMA, the Flavor and Extract Manufacturers Association. FEMA is an industry trade group. Its expert panel gets paid by member companies. FEMA has cleared substances like isoeugenol, which caused liver tumors in 80% of male mice in NTP tests. That one would fail a fair Delaney-rule review.

The other agencies do this work:

  • FDA runs U.S. GRAS, color additives, and contaminants.
  • EFSA runs the EU E-number system (E100s for colors, E200s for preservatives, E300s for antioxidants, E400s for thickeners and emulsifiers, E600s for flavor enhancers). EFSA publishes OpenFoodTox and sets an Acceptable Daily Intake for each substance.
  • JECFA (the Joint FAO/WHO Expert Committee) handles global reviews that anchor Codex standards.

EFSA reviews each substance once and gives it a numeric ADI. The FDA reviews each intended use. A substance can be safe at 0.01% of a baked good and then show up at 0.1% of a new product with no fresh review. Add the GRAS loophole and you get no data on stacking effects. Nobody is testing what happens when you eat 14 emulsifiers a day for 40 years.

The main additive groups

Every additive does one of 7 jobs.

Emulsifiers keep oil and water mixed. Lecithin is the old one. Industry added carboxymethylcellulose (CMC, E466), polysorbate 80 (E433), DATEM (E472e), and mono- and diglycerides (E471). They let supermarket ice cream sit in a warm aisle. They keep bread soft for 3 weeks.

Gums and thickeners copy the texture of fat or dairy. Xanthan comes from bacteria. Guar comes from beans. Locust bean comes from carob. Carrageenan comes from red seaweed. Modified starches do the same work in dressings, fillings, and frozen meals.

Preservatives stop microbes or going rancid. Sodium benzoate (E211) and parabens block yeast and mold. Propionates keep bread from molding. Sodium nitrite (E250) cures bacon and lunch meats. BHA, BHT, TBHQ, and propyl gallate are man-made antioxidant preservatives that slow fat oxidation in cereals, gum, and oils.

Antioxidants stop fat from going rancid. Ascorbic acid (E300) and tocopherols (E306–E309) are the safe vitamin forms. BHA, BHT, TBHQ, and propyl gallate are the man-made ones. This group splits hard.

Colorants come in two types. Man-made FD&C dyes include Red No. 3, Red No. 40, Yellow No. 5 (tartrazine), Yellow No. 6, and Blue No. 1. "Natural" colors include caramel, beet juice, annatto, paprika, carmine, and turmeric. The word "natural" hides a lot. Class IV caramel holds 4-methylimidazole, which causes cancer in animals. FD&C dyes come from coal tar.

Flavor enhancers make food taste more savory than its protein content earns. MSG (E621) is the famous one. Hidden glutamates do the same job under other names: hydrolyzed vegetable protein, autolyzed yeast extract, soy protein isolate, "natural flavors." These let brands dodge MSG warnings. Disodium inosinate (E631) and disodium guanylate (E627) boost glutamate. If you see them, glutamate is somewhere else on the label.

Artificial sweeteners include aspartame (E951), sucralose (E955), acesulfame K (E950), and saccharin (E954). Newer ones include stevioside (E960), neotame, and advantame.

Learn the 7 groups and you can decode 90% of any label. The skill is knowing which entries actually matter.

The ones to pay attention to

GoodEnough scores ingredients 1 to 5. Scores draw from Winter, Lustig, van Tulleken, Moss, and primary toxicology. The watchlist (concern 4 and 5) is short.

Trans fats and partial hydrogenation (scored 5 in the past; banned 2018). These drove heart disease for 50 years. They prove a whole additive class can be wrong. Under 0.5 grams per serving still rounds to "0g trans fat" on labels that list "partially hydrogenated."

Sodium nitrite (5). Cured meats like bacon, hot dogs, and salami are IARC Group 1 carcinogens. Same class as tobacco. Nitrite mixes with amines under heat to form nitrosamines, which cause cancer in lab animals at tiny doses. The FDA proposed a phase-out in 1980 and dropped it for lack of a swap-in. Treat cured meats as a rare item.

CMC and polysorbate 80 (both 4). Chassaing and Gewirtz 2015 (Nature) tested these two emulsifiers at doses people really eat. The result in mice: low-grade gut swelling, metabolic syndrome, and gut microbe shifts. A 2022 human controlled-feeding trial showed CMC changed the human gut microbiome in 11 days. Why: emulsifiers break up fat layers, and the gut's mucus shield is built from fat.

Most coal-tar dyes (usually 4). Red No. 3 (E127) was banned in U.S. cosmetics in 1990 for thyroid cancer in rats. It stayed in food 35 more years. The FDA finally banned it in 2025. The 2007 Southampton study tied 6 common dyes plus sodium benzoate to child hyperactivity. The EU now requires a warning label. The FDA does not.

BHA and BHT (both 4). These man-made antioxidants live in cereals, gum, shortenings, and animal fats. NTP lists BHA as "reasonably anticipated to be a human carcinogen." Both caused rodent tumors. BHT changed brain chemistry in mouse pups. Japan banned BHA. The U.K. banned BHT in food. The U.S. keeps both as GRAS. TBHQ (4) comes from oil, and 5 grams is a lethal dose. Propyl gallate (3) is the milder cousin.

Most artificial sweeteners (aspartame, sucralose: 4; acesulfame K: 3). Suez 2014 (Nature) showed sucralose, saccharin, and aspartame changed the gut microbes and set off glucose intolerance in mice. A small human group showed the same pattern. Lustig and Means argue sweeteners split sweetness from calories, which breaks the insulin response. NutriNet-Santé 2022 found dose-based heart-disease links to aspartame. IARC moved aspartame to Group 2B in 2023. No single study is a smoking gun. Stacked, they point one way: the diet-soda bet was wrong.

Hidden glutamates (MSG: 4; autolyzed yeast, hydrolyzed proteins: 3–4). Whether MSG itself causes "Chinese restaurant syndrome" is still in dispute. What is settled: free glutamate boosts taste and skips the normal full-signal. The umami taste bud reads "protein incoming," but no real protein follows in a Pringle or KFC seasoning. Hidden glutamates matter more than MSG. Label rules let brands print "No MSG" on products full of autolyzed yeast.

High-fructose corn syrup (5). HFCS is a sweetener, not an additive in the strict legal sense. It still belongs here. The liver handles 100% of fructose you eat. It drives new fat output, sticks to proteins 7 times faster than glucose, and fills no need your body has. HFCS is the main path for that effect across U.S. packaged food.

That's the watchlist. About a dozen substances and families. Avoid them and you avoid 90% of the additive-related harm in the source material.

The ones to mostly ignore

The scary-but-fine list is much longer.

  • Xanthan gum (3). A bacterial product. Safe at normal doses.
  • Guar gum (3). A bean-endosperm fiber. Mostly inert.
  • Lecithin (3). A phospholipid, the same kind in egg yolk. Not in the polysorbate-80 class.
  • Citric acid (2). Made by fermenting Aspergillus niger. Same molecule as in lemons.
  • Ascorbic acid (2) and tocopherols (2). Vitamins.
  • Class I and II caramel color (3). Toasted sugar. The ammonia-based types carry the 4-methylimidazole concern.

Here is the trap. A product with xanthan is almost sure to be ultra-processed even though xanthan itself is fine. Its presence flags a factory formula. That means other things on the label are doing the damage. A single safe additive is not the issue. The setup that needs 14 of them is.

What the regulators actually do

The U.S. and EU split on 3 things.

Burden of proof. EFSA wants safety proof. The FDA takes self-certification.

Openness. EFSA publishes OpenFoodTox, which lists every reviewed item, its ADI, and the studies behind it. The FDA's PAFA database is partial and dated. It misses the 1,000 self-declared GRAS items.

Speed of pull-back. EFSA re-reviewed titanium dioxide in 2021 and said it was no longer safe. It re-reviewed aspartame in 2023. The FDA's reply to the 2007 Southampton hyperactivity data was no change.

The Delaney Amendment is the 1958 rule that bans any animal carcinogen from food. It forced the Red No. 3 ban in 2025. It also shows how most additives dodge review: proof of cancer needs a study someone paid for, and nobody paid for studies on the 1,000 self-declared GRAS substances.

"Natural" colorants are their own quirk. The 1960 Color Additive Amendments grandfathered "exempt from certification" items (caramel, annatto, beet juice, carmine, paprika) into a softer track. Ammonia-based caramel would fail the FD&C-dye review it was exempted from. The lesson is not "natural means safer." It is "we wrote the rules before we knew."

The GoodEnough scoring approach

GoodEnough scores every substance on 2 axes.

Concern level (1 to 5). A blend of toxicology, legal status across countries, and how-it-works proof in the anchor books.

  • Level 1. No concern at any normal dose.
  • Level 2. Allowed everywhere. No known way it harms you. Examples: citric acid, ascorbic acid.
  • Level 3. Allowed and mostly inert, but a sign of factory food or with edge-case concerns. Examples: xanthan, lecithin, caramel color.
  • Level 4. Real proof of harm, or banned in several countries. Examples: BHA, BHT, polysorbate 80, CMC, MSG, aspartame, most coal-tar dyes.
  • Level 5. Proven carcinogen, proven metabolic harm, or banned in the U.S. Examples: sodium nitrite, HFCS, trans fats.

NOVA-4 marker (yes/no). Some additives show up only in factory food. Xanthan scores 3 for concern but flags as a true NOVA-4 marker. Its presence means the product was built, not cooked.

Concern level answers: should I avoid this substance? The NOVA-4 marker answers: what kind of food is this? A product can score low on concern (lecithin, xanthan, citric acid) and high on NOVA-4 marker count. That is the working test for ultra-processed. A different product can have 1 high-concern ingredient (nitrite in butcher's bacon) and zero NOVA-4 markers. Different choices. Every score in the canonical database links to the underlying claim.

Frequently asked questions

Is aspartame OK?

Probably not. IARC moved it to Group 2B (maybe carcinogenic) in 2023. The 2022 NutriNet-Santé cohort found dose-based heart-disease links. Suez 2014 showed gut microbiome harm. No single finding is a smoking gun. The pattern points toward harm. Concern level 4. Drink water.

Is xanthan gum bad?

Mostly no. Concern level 3. Its presence is a NOVA-4 marker, so the product is factory food. The gum itself shows no steady harm at normal doses. Avoid the product for what xanthan flags, not for the xanthan.

Is "no artificial colors" a meaningful claim?

Sometimes. It means no FD&C dyes. It does not rule out caramel color (4-methylimidazole), annatto, carmine, or titanium dioxide (banned in EU food, allowed in U.S.). It beats "natural." It loses to "no added color of any kind."

What's the deal with E-numbers?

They are EU label IDs. E300 is ascorbic acid. E621 is MSG. E471 is mono- and diglycerides. The system makes EU labels easy to scan because every code links to a public database. U.S. labels use full names, which scan worse. An E-number is not a danger sign. Vitamin C has one.

Why does the U.S. allow what the EU bans?

Three reasons. EFSA wants safety proof; the FDA takes self-certification. EFSA acts faster, and industry money captures it less. EU member states label and restrict additives more often. The FDA's food side has lacked funding next to its drug side since the 1980s.

Are FDA approvals trustworthy?

Drug approvals, mostly yes. Food approvals, mostly no. Most since 2000 are self-declared GRAS, which the FDA never reviewed. The agency still does real work on color additives, food-contact materials, and contaminants. It does little on the bulk of new additives because the law no longer makes it.

Should I avoid all emulsifiers?

No. Lecithin in small amounts is fine. Mono- and diglycerides at normal doses are likely fine. Egg yolks and milk are emulsifiers. The 2 the evidence calls out are polysorbate 80 and CMC. The useful rule is not "avoid emulsifiers." It is "avoid products that need emulsifiers to exist."

Sources

  1. Winter, R. A Consumer's Dictionary of Food Additives, 7th ed. Three Rivers Press, 2009. Entry-by-entry toxicology and regulatory status for ~12,000 substances.
  2. van Tulleken, C. Ultra-Processed People. W. W. Norton, 2023. The GRAS loophole, the FEMA arrangement, the Maffini-Neltner evidence, the emulsifier-microbiome literature.
  3. Lustig, R. H. Metabolical. Harper Wave, 2021. The eight subcellular pathologies; the case for removing fructose from GRAS.
  4. Moss, M. Salt Sugar Fat: How the Food Giants Hooked Us. Random House, 2013. How industry deploys these substances at the formulation, marketing, and policy levels.
  5. Chassaing, B., et al. (2015). "Dietary emulsifiers impact the mouse gut microbiota promoting colitis and metabolic syndrome." Nature, 519, 92–96.
  6. Chassaing, B., et al. (2022). "Randomized controlled-feeding study of dietary emulsifier carboxymethylcellulose reveals detrimental impacts on the gut microbiota and metabolome." Gastroenterology, 162(3), 743–756.
  7. Suez, J., et al. (2014). "Artificial sweeteners induce glucose intolerance by altering the gut microbiota." Nature, 514, 181–186.
  8. IARC Monograph 114 (2015). Red and Processed Meat — Group 1 carcinogen classification.
  9. Debras, C., et al. (2022). "Artificial sweeteners and cancer risk: NutriNet-Santé cohort." PLOS Medicine, 19(3): e1003950.
  10. EFSA. OpenFoodTox database.
  11. Neltner, T. & Maffini, M. (2014). "Generally Recognized as Secret: Chemicals Added to Food in the United States." Environmental Defense Fund.

Related glossary terms

Related ingredients