Food additive discourse tends toward two opposite and equally unhelpful positions. Position one: all E-numbers and additives are toxic and any processed ingredient should be avoided. Position two: all approved additives have been thoroughly tested and anything allowed in the food supply is safe. Neither is accurate.
The regulatory approval process for food additives is imperfect. Studies used to establish safety limits are often industry-funded, conducted over short timeframes, and don't account for combined exposure. Some additives approved decades ago have since accumulated evidence suggesting they warrant reconsideration. Others have strong safety records across many decades of use.
The goal here is to identify the ones worth actually paying attention to.
◈Key Facts
The additives with the strongest evidence for concern
Artificial food dyes
Red 40, Yellow 5 (tartrazine), Yellow 6, Blue 1, Blue 2, Green 3 — synthetic petroleum-derived dyes used to colour processed foods. The EU requires a warning label on products containing six of these dyes: "may have an adverse effect on activity and attention in children." The US FDA does not require this warning.
The evidence linking these dyes to hyperactivity in susceptible children is considered sufficient for the EU label requirement. For adults the evidence is less studied, but these dyes serve no nutritional purpose and the EU regulatory position suggests precaution is warranted.
Sodium nitrate and sodium nitrite
Used as preservatives and colour fixatives in processed meats (bacon, hot dogs, deli meats, salami). Under certain conditions — particularly high heat cooking and in the acidic environment of the stomach — they form nitrosamines, which are classified as probable carcinogens.
This is the basis for the WHO's classification of processed meat as a Group 1 carcinogen (sufficient evidence of carcinogenicity in humans). The risk is dose-dependent and context-dependent — occasional consumption is different from daily processed meat consumption.
Brominated vegetable oil (BVO)
BVO was used in some citrus-flavoured soft drinks as an emulsifier. Bromine accumulates in the body and has been associated with thyroid disruption and neurological effects at higher exposures. Banned in the EU and Japan, and recently removed from the FDA's approved list in the US (2023). Still may appear in some products during transition periods.
Potassium bromate
A flour additive used to strengthen dough. Classified as a possible carcinogen. Banned in the EU, Canada, UK, and many other countries. Still permitted in US flour. If baking with US flour or eating US-made baked goods frequently, worth checking.
TBHQ and BHA/BHT
Synthetic antioxidants used to prevent fat oxidation in packaged foods. BHA is classified as a possible carcinogen by the IARC. BHT has shown mixed results in animal studies. Both are banned or restricted in some countries. They're found in a wide range of packaged snack foods, cereals, and frozen foods.
High-fructose corn syrup (HFCS)
Technically more ingredient than additive, but worth addressing. HFCS is not identical to regular sugar — the fructose content is higher (55-90% depending on type vs. 50% in sucrose), and fructose is metabolised differently, primarily in the liver. High fructose intake has been linked to non-alcoholic fatty liver disease, insulin resistance, and elevated triglycerides. Found ubiquitously in US processed food, less so in EU products where sugar is more commonly used.
Additives that are generally fine
Citric acid — derived from citrus or fermentation. Widely used as a preservative and flavour enhancer. Strong safety record.
Ascorbic acid (Vitamin C) — antioxidant preservative. Safe.
Lecithin — typically soy or sunflower-derived emulsifier. Generally well-tolerated.
Xanthan gum — fermentation-derived thickener. Generally safe, though can cause digestive discomfort in large amounts.
Carotene/beta-carotene — natural colouring from plant sources. Safe.
Tocopherols (Vitamin E) — natural antioxidant preservatives. Safe.
Emulsifiers and the gut microbiome question
This is an emerging area of concern worth watching. Carboxymethylcellulose (CMC) and polysorbate-80 (P80), two widely used emulsifiers in ice cream, baked goods, and processed foods, have been shown in animal studies to disrupt gut mucus layers and alter microbiome composition in ways that promote low-grade inflammation.
Human data is limited, but the mechanism is biologically plausible and the animal evidence is consistent. The concern is less about individual products and more about the cumulative effect of emulsifiers appearing in most processed foods eaten daily.
The most useful thing to know about food additives is that the fewer ultra-processed foods you eat, the less you need to think about them. Additives are a feature of processed food, not whole food.