We eat with our eyes. Before even taking a bite, we judge our food’s freshness, taste, and flavour by its colour, influencing upwards trends in the development of genetically modified organisms (GMOs), selective breeding, and the use of food dyes. As arguably the easiest, fastest, and cheapest way to make food more visually appealing, the use of food dyes has become an industry standard, allowing companies to establish their brand identity and sell their products at a higher price. Through years of careful marketing strategies, brighter has effectively become synonymous with better.

While it might be intuitive that most processed foods are formulated with colorants, food dyes are commonly used in fruit, cheese, meat, fish, and more, to the extent that the natural colour of many of these items might no longer be recognized as ‘natural’ at all. Food dyes are added to margarine to give it a butter-like yellow colour, most candies rely on dyes for their visual appeal, and American cheddar cheese is characteristically orange due to pigments added during the manufacturing process. Food dyes aren’t always necessarily added during final-stage processing either. Farmed salmon is naturally grey, as the fish are less active than those who spend their lives in the wild. To compensate and produce a more attractive product, farmed salmon are commonly fed a diet rich in red pigments. The same principle applies to eggs: factory-farmed yolks often get their colour due to hens being fed yellow pigments. Without food dyes, the classic sunny-side-up complexion we associate with eggs wouldn’t be as common.
According to a 2008 study, approximately 640,000 tonnes of natural or synthetic food dyes are produced each year, with a market value exceeding $11 billion USD. This represents a 500% increase in food dye production over the previous 50 years. Natural colour additives, derived from fruits, vegetables, herbs, minerals, and insects, are the best option when used in animal feedstocks. For other applications, synthetic food dyes are preferred by industry as they provide more uniform colour, don’t affect flavour or texture, are easily blended with other ingredients, and are relatively inexpensive. Isolating natural pigments from their origin can be an expensive and time-consuming process, whereas synthesizing artificial dyes is relatively straightforward. However, despite their superior performance and low cost, synthetic food dyes have cause for concern when it comes to the health of the environment and the consumer.
Artificial food dyes are a product of the petrochemical industry, being derived from petroleum or coal tar. Because of this, to be able to be used in food, approved synthetic dyes have to meet strict legal controls. Each batch of artificial food dye is carefully screened for contaminants, like organic solvents or heavy metals, before it can be brought to market. Not only that, but very few synthetic food dyes are approved for use to begin with, as most known artificial pigments are inherently toxic when ingested. Approved food dyes are carefully studied to determine which compounds are safe for use, with which foods, and in what concentrations. These laws vary from country to country. For example, the Canadian government permits the use of 10 synthetic food dyes, the American FDA approves nine options, and the European Food Safety Authority (EFSA) allows a total of 16. Although a 2017 study comparing EU and US regulations found that both groups had well-established risk-assessment and management procedures, this lack of uniformity between countries can lead to confusion when it comes to importing or exporting certain foods, as well as distrust of this legislation in the public eye.
Food dyes that are accepted by one country but banned by another are obvious targets of food-dye-fear, but even those that are used worldwide are often met with controversy. Red 40, otherwise known as Allura Red, is arguably the most well known of this category. Used in everything from pickles to Powerade, Red 40 has been linked to attention deficit hyperactivity disorder (ADHD), allergies, and learning difficulties in certain individuals. As evidence is still mostly anecdotal, Red 40 is still used in Canada, the United States, the European Union, and many other countries, although this may change as new studies are published. Until then, just as with all other artificial food dyes, consumers should at least be aware of the potential risks so they can make well-informed decisions for themselves and their families.

While it may be harder to concretely prove the effects of synthetic dyes on human health, it is well documented that synthetic dyes have a negative effect on the environment. Between 10 and 15% of artificial food dyes are directly discharged in wastewater during manufacturing processes. In these quantities, water becomes notably colored, reducing the amount of sunlight that can reach marine organisms. This reduces photosynthesis by marine plants and microorganisms, which in turn reduces levels of dissolved oxygen in the water. Then, if dissolved oxygen drops below a critical concentration, fish and other marine animals can suffocate and die. These dyes do eventually decompose, or they dissipate by being consumed by plants or animals, but their metabolic and degradation products can be carcinogenic or mutagenic to certain species. In the environment they affect vegetation, vertebrates, and invertebrates differently, but in all cases have lasting negative effects on the organism.
As food dyes are solely used for aesthetic reasons, it begs the question: are these human-health and environmental risks really worth it? True, artificial food dyes are carefully monitored and kept at levels well below potential toxicity thresholds, but with natural alternatives available (albeit at a greater cost) or the choice to forgo food dyes altogether, for many consumers the potential consequences may outweigh the rewards. While we can’t forget that it’s the dose that makes the poison, it’s useful to be aware of what goes into the food we eat so that we can make the most well-informed decisions for our health, as well as the health of our planet.
Advice to consumers:
- If you’re concerned about consuming artificial food dyes, look for labels that indicate that no synthetic pigments have been used.
- Read the ingredients lists: if the name of a colour appears, the product has likely been formulated with a synthetic dye. Examples include Red 1, Blue 2, etc.