Original Pork Pie

What it is. A curing salt that keeps cured and processed meats pink and stops the growth of the bacteria behind botulism.

Why it is used. Used in bacon, ham, salami and hot dogs for preservation, safety and colour.

What the evidence says. The concern is not the additive in isolation but processed meat as a whole, which the WHO's cancer agency IARC classes as Group 1, meaning there is sufficient evidence it causes colorectal cancer. Nitrite can form nitrosamines during curing and cooking, and those are the likely culprit. Risk rises with how much processed meat you eat over time.

Permitted with strict maximum levels. The EU cut the allowed limits further from 2023 to reduce nitrosamine formation.

Assessed against IARC, EFSA, UK FSA. Full entry for E250

What it is. A curing agent that slowly converts to nitrite in the product, giving a longer acting preservative effect.

Why it is used. Used in dry cured meats and a few traditional cheeses.

What the evidence says. Sits under the same processed meat evidence as nitrite, since it ends up as nitrite in the food. Same practical takeaway: the issue is regular processed meat intake, not a trace in one meal.

Permitted with maximum levels, tightened in the EU alongside nitrite.

Assessed against IARC, EFSA, UK FSA. Full entry for E251

What it is. A gel forming fibre extracted from red seaweed.

Why it is used. Thickens dairy, plant milks, desserts and some processed meats.

What the evidence says. Food grade carrageenan is permitted. A degraded form called poligeenan is harmful, but that is not what goes into food. Some lab and animal work links carrageenan to gut inflammation, which keeps it under review, but human evidence is limited and mixed.

Permitted, including in organic food in many places, though a few specialist products avoid it as a precaution.

Assessed against EFSA, JECFA. Full entry for E407

What it is. A modified plant fibre used to thicken and stabilise.

Why it is used. Common in ice cream, low fat products, gluten free bakery and sauces.

What the evidence says. Falls in the same emulsifier and gut research bucket as polysorbate 80, with early human work hinting at effects on the microbiome. Interesting, not conclusive.

Permitted with limits.

Assessed against EFSA. Full entry for E466

What it is. The orange pigments found in carrots and other vegetables, either extracted or made synthetically.

Why it is used. Colours margarine, soft drinks, dairy, and sweets.

What the evidence says. The same compound the body turns into vitamin A, and safe at the levels used in food. High dose beta-carotene supplements have been linked to harm in smokers, but those doses are far above anything a colour in food delivers, and conflating the two is a common mistake.

Permitted. The supplement findings apply to concentrated doses, not to food colouring.

Assessed against EFSA, JECFA. Full entry for E160A

What it is. Vitamin C, added to protect colour and flavour and sometimes to fortify.

Why it is used. Stops browning in juices and cut fruit, protects fats, and boosts vitamin content.

What the evidence says. Beneficial and harmless at the levels used. Included here as a reminder that an E number is just a code, and plenty of them are ordinary nutrients.

Permitted freely, no concern.

Assessed against EFSA, JECFA. Full entry for E300