Examining the Safety of Food Dyes

On April 22, 2025, the U.S. Department of Health and Human Services (HHS) and U.S. Food and Drug Administration (FDA) announced that they would begin to phase out the use of all synthetic, petroleum-based dyes in food (FDA 2025). The safety of synthetic food dyes has long been a target of public scrutiny, with frequently cited concerns about possible neurobehavioral and carcinogenic effects of these additives. Many companies are working to transition to more naturally derived colorants, with several high-profile moves by major players announced this summer.

In June, Nestlé said that it would remove synthetic food colors from all of its products worldwide by the end of 2026, and Mars said it would offer a naturally colored version of its iconic M&M’s—minus brown and blue M&M’s, which have proven difficult for the candy company to replicate at scale without artificial dyes.

Colorants have been added to food for centuries, albeit by slightly different methods than we use today. Think saffron to dye foods yellow or paprika to turn them red. Synthetic food dyes were introduced sometime around the 18th century thanks to advancements in the field of chemistry. Unfortunately, many of these new dyes contained toxic substances, such as mercury and arsenic, or were used to deceive consumers about the ingredients or freshness of the products (Burrows 2009).

The food industry has come a long way since those days. Both synthetic and natural colorants are regulated as additives by the FDA and must be proven safe for consumption prior to being approved for use (Lehto et al. 2017, FDA 2023).

The safety of synthetic food dyes has long been a target of public scrutiny, with frequently cited concerns about possible neurobehavioral and carcinogenic effects of these additives.

The FDA reports that there are currently six synthetic colors frequently used in foods and beverages in the United States: FD&C Blue No. 1, FD&C Blue No. 2 , FD&C Green No. 3, FD&C Red No. 40, FD&C Yellow No. 5, and FD&C Yellow No. 6 (FDA 2026). There are currently more synthetic food colorants approved for use in the European Union than in the United States (Lehto et al. 2017, Ajanta Food Colors 2026). This is not to say that these regulations are right or wrong; both entities have protocols for assessing and monitoring the safety of such additives. However, it does provide a counter to one of the arguments against the use of food colorants in the United States.

Regarding the potential carcinogenicity of food dyes, the evidence is scarce. Studies investigating the issue link food dyes with pro-oxidative effects in rats and mice fed high doses of food dyes daily for anywhere from 30 days to 10 months (Khayyat et al. 2018, Zhang et al. 2023, Neal et al. 2026). These effects were demonstrated only on the cellular level, though, with the potential for carcinogenicity presumed based on theory rather than clinical observation.

As for the neurobehavioral effects of food dye consumption, research results have been mixed, with most studies focusing on a potential link between synthetic food dyes and attention deficit hyperactivity disorder (ADHD). A 2012 meta-analysis looked at studies in which children were placed on restriction diets and then given foods containing various additives, including synthetic colorants (Nigg et al. 2012). The authors noted that the additives studied included more than food colorants alone, and that the studies were conducted both inside and outside of the United States, often using colors not approved for use in the United States. That said, even after adjusting the results for publication bias and heterogeneity, there did seem to be a signal toward food dyes increasing ADHD symptoms (Nigg et al. 2012).

Despite the lack of strong evidence that synthetic dyes are unsafe, the pendulum is expected to continue to swing in the direction of natural colors, with the food industry working to identify new and creative solutions to maintain the colors that consumers expect without the use of synthetic dyes. In general, natural pigments are derived from plants, animals, minerals, and microorganisms, such as algae and fungi. Dyes produced by microorganisms, in particular, seem poised to take over for synthetic dyes, thanks to their stability, ease of processing, and wide range of available colors (Li et al. 2022).