Food colouring refers to additives used to impart, enhance, or restore the colour of food and beverages. They can be either synthetic (artificial) or natural, derived from plants, minerals, or animals.
Manufacturers use food colouring to make products more visually appealing, as bright colours are associated with freshness and quality. They also help compensate for the loss of natural colour that occurs during processing, freezing, and storage. Additionally, specific shades create a recognizable product image—for example, oranges are dyed to meet consumer expectations.
In this article, we will explore which food colourings are potentially harmful, which are considered relatively safe, and how to minimize their consumption.
Prevalence of Food Colouring in Modern Production
Food colourants are widely used in processed products, especially in those where appearance plays a key role. Below are the main categories in which they are found:
- Carbonated drinks, juices, and energy drinks – synthetic dyes give them bright, intense colours.
- Confectionery products – candies, chewing gum, jelly, glazes, and cakes are coloured to enhance visual appeal.
- Dairy products – flavoured yoghurts, ice cream, and cottage cheese desserts contain dyes to enhance their colour.
- Processed meats and meat products – dyes are used to give a “natural” appearance, such as the pink colour of cooked sausages.
- Sauces, seasonings, and ready-made meals – ketchup, mayonnaise, and dry mixes are often coloured to maintain a consistent hue.
- Fast food – dyes are added to buns, beverages, and glazes, for example, to create a recognizable brand colour.
- Baked goods – dyes are used in biscuits, croissants, and doughnuts for an even colour.
- Canned foods and marinades – vegetable and meat preserves contain dyes to retain their appetizing look.
- Meal replacements and sports nutrition – protein bars and powdered mixes contain dyes to mimic natural ingredients.
Unexpected Cases of Food Colouring
In addition to their use in processed foods, dyes may also be applied to products where their presence is not obvious. They help align the appearance of products with consumer expectations, creating an illusion of freshness, quality, or naturalness. However, these dyes do not appear on the label, as the treatment occurs during transportation, storage, or even at the growing stage.
- Oranges and lemons – their peel may be dyed if the fruit lacks a sufficiently bright colour. A notable example is Florida oranges, which often have uneven skin colouring, ranging from green to light orange. To meet consumer expectations, they are dyed with a substance that is banned for other food products due to its potential carcinogenic effects. This is why it is best to avoid using citrus zest if you are unsure whether it has been treated with dye.
- Salmon and trout – farmed fish are fed carotenoid supplements to keep their flesh pink (otherwise, it would be grey).
- Shrimp – sometimes treated with dyes if their natural colour is too pale.
- Honey – counterfeit or diluted honey may be coloured with caramel dyes to make it look more authentic.
- Black olives – in reality, these are green olives artificially coloured with ferrous gluconate to achieve a rich black hue.
- Apples – may be coated with dyes and wax to create a smooth, shiny appearance.
- Potatoes – the skins of some varieties are treated with dyes to remove blemishes and give them a fresher look.
- Beef – in supermarkets, meat is sometimes treated with carbon monoxide or carmoisine to maintain a bright red colour, even if it is no longer fresh.
- Margarine – coloured yellow to resemble butter.
- Olive oil – cheaper varieties are dyed with chlorophyll or annatto to make them look greener and fresher.
- Egg yolk – its colour depends on the hen’s diet, but colourants like canthaxanthin (Carophyll) are often added to poultry feed to enhance the yellow hue. These additives are not regulated, and acceptable levels vary by country.
- Salt – in addition to the colouring of “exotic” varieties (such as pink Himalayan salt), regular table salt may be bleached and treated with optical brighteners to achieve a perfectly white colour.
- Sugar – refined white sugar may contain titanium dioxide to enhance its whiteness.
- Tea – cheap varieties may contain dyes to give the infusion a deeper colour.
- Coffee – caramel colouring is sometimes added to ground coffee to create a darker hue.
- Pistachios – in the past, they were often dyed red, and this practice persists in some countries.
- Peanuts in shells – may be treated with dyes to give them a uniform shade.
- Dried fruits (apricots, raisins, figs) – sometimes artificially coloured to maintain a rich hue after drying.
As these examples show, even whole foods can undergo hidden colouring. To minimize the consumption of such additives, it is best to choose seasonal, locally sourced products that do not require additional processing to enhance their appearance.
Food Colouring: How Safe Is It?
By now, it is clear that food colouring is used almost everywhere. Its application is regulated by governmental bodies such as Health Canada (Canada), the FDA (USA), the EFSA (European Union), and others. However, some colourants that are permitted in certain countries are banned in others due to potential health risks.
The main concerns associated with food colouring include potential allergic reactions and hyperactivity in children, links to cancer development, effects on gut microbiota, possible toxic impacts on the liver and kidneys, and disruption of the endocrine system as potential endocrine disruptors.
Classification of Food Colouring
Food colourants fall into two main categories: synthetic (certified) and natural (exempt from certification). The difference lies in their source, application, and level of regulation.
Synthetic (Certified) Colourants
Synthetic dyes are chemically produced to provide products with stable and intense colours. They can be either water-soluble or insoluble pigments and are derived from petroleum or coal tar. Certification is necessary since these substances do not naturally occur in food, may contain impurities, and require toxicity testing.
FD&C Blue No. 1 (E133)
- Used in: beverages, ice cream, confectionery products.
- Status: approved in the USA and Canada.
- Bans: no full bans reported.
- Risks: allergic reactions, hyperactivity in children.
- Additional concerns: may reduce levels of Bifidobacterium and Lactobacillus when consumed in high amounts.
FD&C Blue No. 2 (E132)
- Used in: desserts, frozen foods, dry mixes.
- Status: approved in the USA and Canada.
- Bans: no full bans reported.
- Risks: allergic reactions; potential carcinogenic effects under study.
FD&C Green No. 3 (E143)
- Used in: candies, jelly, cereals, canned vegetables, desserts, drinks, salad dressings, medications.
- Status: approved in the USA and Canada.
- Bans: banned in some countries.
- Risks: possible allergic reactions.
FD&C Red No. 40 (E129)
- Used in: sweets, soda, flavoured yoghurts, ice cream, sauces.
- Status: approved in the USA and Canada.
- Bans: banned in some EU countries.
- Risks: hyperactivity in children, allergic reactions.
- Additional concerns: may cause inflammation in the gut and alter gut microbiota composition.
FD&C Yellow No. 5 (E102)
- Used in: soft drinks, chips, candies, jelly, ready-made desserts, sports drinks.
- Status: approved in the USA and Canada.
- Bans: banned in Norway and Austria; requires a warning label in the EU.
- Risks: allergies, hyperactivity in children, sensitivity in asthmatics.
- Additional concerns: may alter populations of beneficial gut bacteria.
FD&C Yellow No. 6 (E110)
- Used in: fast food, confectionery, drinks.
- Status: approved in the USA and Canada.
- Bans: banned in Norway and Finland.
- Risks: allergic reactions, hyperactivity in children.
FD&C Red No. 3 (E127)
- Used in: candies, icing, maraschino cherries, cake decorations, pharmaceuticals.
- Status: banned in the USA since 2024 but allowed until January 15, 2027; approved in Canada.
- Bans: banned in the USA, Australia, Japan, and some EU countries.
- Risks: linked to thyroid cancer, potential behavioural effects in children.
FD&C Orange No. 1 and No. 2
- Previously used in: food products.
- Status: banned in the USA and Canada.
- Bans: prohibited in most countries.
- Risks: identified as carcinogenic.
FD&C Citrus Red No. 2
- Used in: colouring orange peels only.
- Status: approved in the USA (only for oranges), approved with restrictions in Canada.
- Bans: banned in some EU countries.
- Risks: potential carcinogenic effects if consumed in large amounts.
This classification highlights the different regulatory approaches taken in various countries regarding food dyes and the concerns associated with their safety.
Natural (Exempt from Certification) Food Colouring
Natural food colourants are derived from natural sources, including plants, minerals, and animal products. Plant-based colourants include turmeric, beetroot, annatto, and grape skin extract. Mineral-based dyes include iron oxides and titanium dioxide. Among animal-derived sources, the most well-known is carmine, which is extracted from cochineal insects. Many natural colourants lose their intensity when exposed to heat, freezing, or acidic environments.
These dyes do not require certification, but their safety must be confirmed through toxicological studies.
Annatto (E160b) – Orange
- Source: Extracted from annatto tree seeds.
- Status: Approved in the USA and Canada.
- Bans: No full bans reported.
- Risks: May cause allergic reactions in sensitive individuals.
Beta-Carotene (E160a) – Yellow-Orange
- Source: A natural pigment found in carrots, pumpkins, and spinach.
- Status: Approved in the USA and Canada.
- Bans: No full bans reported.
- Risks: High doses may cause carotenodermia (a harmless yellow-orange skin discolouration).
Beetroot Extract (E162) – Red, Pink
- Source: Derived from natural beetroot juice.
- Status: Approved in the USA and Canada.
- Bans: No full bans reported.
- Risks: Considered safe.
Carmine (E120) – Red
- Source: Extracted from cochineal insects.
- Status: Approved in the USA and Canada.
- Bans: Banned in some countries due to allergy concerns.
- Risks: May cause severe allergic reactions, especially in people sensitive to insects. Also raises ethical concerns as it is derived from insects.
Grape Skin Extract (E163) – Purple, Red
- Source: Derived from grape skins.
- Status: Approved in the USA and Canada.
- Bans: No full bans reported.
- Risks: Considered safe.
Caramel Colour (E150a-d) – Brown
- Source: Formed by heating sugars. Some variations of caramel colouring may contain 4-methylimidazole (4-MEI), a substance linked to cancer in animals.
- Status: Approved in the USA and Canada. Due to public pressure, Coca-Cola and Pepsi have reduced 4-MEI levels.
- Bans: In the USA (California), a warning label is required for 4-MEI. Restrictions also exist in the EU, China, and Canada.
- Risks: Potential carcinogenicity of 4-MEI, particularly in E150c and E150d. Acceptable levels of this compound have been regulated.
Chlorophyll (E140) – Green
- Source: Extracted from green plants.
- Status: Approved in the USA and Canada.
- Bans: No full bans reported.
- Risks: Considered safe.
Curcumin (E100) – Yellow
- Source: Extracted from turmeric root.
- Status: Approved in the USA and Canada.
- Bans: No full bans reported.
- Risks: Considered safe.
Titanium Dioxide (E171) – White
- Source: A mineral pigment derived from the natural mineral rutile.
- Status: Approved in the USA and Canada.
- Bans: Banned in the European Union since 2022.
- Risks: The European Food Safety Authority (EFSA) cannot rule out its potential genotoxicity (possible DNA damage).
- Additional concerns: May alter gut microbiota and contribute to inflammation.
This classification highlights that while natural food colourants are often perceived as safer than synthetic ones, some still carry potential health risks and require regulation.
How to Reduce the Consumption of Food Colouring?
Completely avoiding food colouring is difficult, but you can significantly reduce your intake by knowing where colourants are commonly used and choosing alternatives.
- Pay attention to colour – Bright, intense shades often indicate the use of artificial dyes, especially if the product has been transported long distances or stored for an extended period.
- Do not blindly trust natural colourants – Even “natural” dyes may pose health risks. For example, titanium dioxide (E171) has already been banned in the EU, and carmine (E120), derived from insects, can trigger allergic reactions.
- Minimize processed foods – The fewer heavily processed products in your diet, the lower the likelihood of consuming artificial dyes. This is especially true for soft drinks, confectionery, fast food, and processed meats.
- Use natural alternatives – If you want vibrant colors in your dishes, replace artificial food colorings with natural ingredients:
- Beetroot – adds red and pink shades.
- Orange carrot – provides a bright orange color.
- Sea buckthorn – when dried and ground, gives a yellow-orange hue.
- Turmeric – used to create a rich yellow color.
- Saffron – imparts a deep golden-yellow shade, most commonly used in baking.
- Matcha (green tea powder) – used for a green color.
- Blueberry – has a dark blue color but turns purple in an acidic environment.
- Blackberry, black currant – give a deep dark purple hue.
- Coconut milk – a natural source of white color.
- Activated charcoal (e.g., coconut-based) – provides an intense black shade.
- Be especially mindful of children’s food – Many products marketed towards kids, such as yogurts, juices, biscuits, and candies, contain synthetic dyes, which have been linked to hyperactivity and allergies.
- Choose local, organic, and seasonal products – Certified organic products do not contain synthetic dyes, and fresh, locally sourced foods do not require artificial colour enhancement.
Conclusion
Food colouring has become an integral part of the modern food industry, helping to create visually appealing products and compensate for colour loss during processing. However, its use is not always harmless—some dyes may trigger allergic reactions, affect gut microbiota, and, in some cases, even have potential carcinogenic properties.
While it is difficult to completely eliminate food colourants, making informed food choices can significantly reduce exposure. Reading ingredient labels, reducing processed food intake, and choosing local, seasonal products that do not require additional colour enhancement all help lower the risk of hidden food dyes.
The best way to reduce the impact of food colouring is to prioritize organic and locally produced foods. The simpler and more natural the ingredient list, the less likely it is to contain hidden additives. Raising awareness about food colourants and making conscious dietary choices is a key step toward healthier eating and better control over food quality.