Recent discussions about food dyes have prompted considerable concern, with social media boosting calls for restrictions at the state and national levels. Critics believe that these compounds, which may be found in anything from sports drinks to morning cereals, may contribute to major health problems such as cancer, behavioural disorders, or obesity. But does focusing on food dyes overlook the greater picture? A closer look at the science suggests that the true health concerns may be in the foods themselves, rather than the colourful additives. 

Food colours are compounds used to improve the appearance of food such as candy, baked goods, and salad dressings. They are classified into two types: natural, which are obtained from plants, minerals, or insects (for example, cochineal for red dye), and synthetic, which are made from petroleum-based compounds. The United States Food and Drug Administration (FDA) has approved nine synthetic dyes, including Blue Nos. 1 and 2, Red Nos. 3 and 40, and Yellow Nos. 5 and 6. However, due to regulatory changes, Red No. 3 will be phased out for food in 2027 and medications in 2028.

"Food dyes are about marketing—they make products bright and tempting, especially for kids," explains Lindsey Smith Taillie, PhD, a nutrition epidemiologist at the University of North Carolina. However, these additions have little nutritional value. Whether natural or synthetic, they do not improve the health benefits of a food. For example, a natural dye derived from beets does not include the vegetable's nutrients, and "natural" does not always imply health. 

Concerns about cancer originate from a regulation mandating the removal of chemicals that cause cancer in animals. The FDA revoked Red No. 3's authorisation in January 2025, citing two tiny studies that found it caused cancer in animals. However, the agency noted that the mechanism—a rat-specific hormone—is not applicable to people. The rats also devoured significantly larger dosages than the average human exposure. 

"Human studies on food dyes and cancer are scarce," explains Taillie. A 2023 review in Food and Chemical Toxicology discovered no compelling data tying permitted synthetic colours to cancer in humans at current intake levels. Animal studies frequently use higher amounts than people's daily diets, making direct comparisons difficult. 

Another point of worry is the potential link between food dyes and behavioural disorders, particularly in youngsters. Products containing dyes, such as sweet cereals and candies, are frequently promoted to children, prompting concerns about their effects on diseases such as attention-deficit/hyperactivity disorder (ADHD). ADHD is a neurodevelopmental disorder characterised by problems maintaining attention or managing impulsive behaviour. 

Over two dozen clinical trials indicate that synthetic colours may aggravate symptoms such as hyperactivity in some youngsters. A 2021 meta-analysis in Paediatrics discovered a tiny but substantial link between synthetic dyes and hyperactivity in sensitive youngsters (DOI: 10.1542/peds.2020-021477). However, Taillie warns, "The notion that removing dyes can cure ADHD is false. The evidence indicates a moderate effect in select circumstances, but not a cause." 

The FDA agrees that certain youngsters may be more sensitive to dyes. Parents who notice behavioural changes after their child consumes dyed foods should see a doctor, as other substances, such as sugar, may also play a role. 

Banning synthetic dyes may not necessarily make foods healthier. "Junk food with natural dyes is still junk food," Taillie explains. Snack foods, whether naturally or synthetically tinted, are generally heavy in sugar, sodium, and fat. These ultraprocessed meals, which are produced in factories and contain additives such as sugars and emulsifiers, are intended to be consumed in excess. 

There is strong evidence that ultraprocessed meals pose health concerns. A 2019 randomised controlled trial in Cell Metabolism found that ultraprocessed meals resulted in more weight gain than minimally processed diets. According to the CDC, excess weight raises the chance of developing type 2 diabetes, heart disease, stroke, and some malignancies. 

The emphasis on food dyes may detract from larger dietary concerns. "We know from rigorous trials that ultraprocessed foods drive weight gain and chronic disease," Taillie tells me. "Fruits, vegetables, whole grains, and dairy are the foundation of a healthy diet." A 2024 study in The Lancet found that diets high in minimally processed foods minimise the risk of obesity-related disorders.

While food dyes aren't always hazardous, their presence frequently indicates ultraprocessed items. Rather than focusing on dyes, researchers suggest prioritising whole foods to reduce long-term health hazards. The dye discussion brings to light a deeper issue: the need for a more focused approach to overall dietary patterns in order to improve health results.