What are the hazards of red dye in food and other products?

November 26, 2025 •

4 min read

In January 2025, the FDA banned the use of Red Dye No. 3 in food and ingested drugs after decades of evidence linked it to cancer in rats. The widespread use of artificial red dyes, such as the now-banned Red 3 and the common Red 40, has prompted significant concern among consumers about their potential health risks.

Quick Summary

This article explores the health risks associated with synthetic red dyes, detailing concerns like hyperactivity in children, potential links to cancer, and allergic reactions. It examines regulatory actions and offers guidance on how consumers can identify and reduce their exposure to these controversial additives.

Key Points

Behavioral Issues: Certain red dyes, especially Red 40, have been consistently linked to hyperactivity and other neurobehavioral problems in sensitive children.
Cancer Risk: Red Dye No. 3, now banned by the FDA for food use, was found to cause thyroid cancer in animal studies, and Red Dye 40 has been linked to DNA damage and inflammation in animal models.
Allergic Reactions: Both synthetic (Red 40) and some natural (carmine) red dyes can trigger allergic or hypersensitivity reactions, including hives, swelling, and respiratory symptoms.
Identification: Consumers can identify synthetic red dyes on ingredient lists by looking for names like FD&C Red No. 40, Allura Red AC, and FD&C Red No. 3.
Regulation Differences: Regulatory standards for red dyes differ globally; for example, the European Union requires warning labels on products containing certain dyes linked to hyperactivity.
Hidden Sources: Red dyes are not only found in visibly red foods but also appear in many processed items, drinks, medications, and cosmetics.
Healthier Alternatives: The primary purpose of these dyes is cosmetic, with safer, natural alternatives derived from fruits, vegetables, or spices often available.

Common Red Dyes and Their Associated Health Risks

Synthetic red food dyes, primarily Red Dye No. 40 (Allura Red AC) and the recently banned Red Dye No. 3 (Erythrosine), are petroleum-derived color additives used to enhance the visual appeal of thousands of products. While they provide no nutritional value, they have been linked to a variety of adverse health effects, triggering public and regulatory scrutiny. Understanding the specific risks associated with these common colorants is the first step toward making more informed dietary choices.

The Behavioral Impacts of Red Dyes, Especially on Children

One of the most heavily researched areas concerning red dyes is their effect on behavior, particularly in children. Decades of studies have explored the connection between artificial color additives and neurobehavioral issues.

Hyperactivity and ADHD: Numerous studies have found a statistically significant association between the consumption of synthetic food dyes and increased hyperactivity in children. A 2021 report from the California Office of Environmental Health Hazard Assessment confirmed that food dyes like Red 40 can cause or exacerbate neurobehavioral problems, including inattentiveness and restlessness, in some sensitive children. The European Union requires products with Red 40 to carry a warning label about potential effects on children's activity and attention.
Mechanisms of Action: Researchers theorize that these behavioral changes may result from mineral depletion, altered brain chemistry, or hypersensitivity reactions. The effects can be particularly pronounced in children with pre-existing conditions like ADHD.

Cancer Concerns Linked to Red Dyes

Cancer risk is another serious concern, especially concerning Red Dye No. 3, which the FDA has explicitly linked to thyroid cancer in animal studies. While Red Dye No. 40's risk profile is less clear, it is not without concern.

Red Dye No. 3: The FDA's 2025 ban on Red 3 in food products was based on studies demonstrating it caused thyroid tumors in lab rats. Although the cancer mechanism found in rats was deemed species-specific, federal law mandates banning additives that cause cancer in animals, leading to this action.
Red Dye No. 40: Research into Red 40's potential carcinogenicity in humans is less conclusive, but animal studies and potential chemical contamination raise flags. The dye has been found to contain trace amounts of known carcinogens like benzidine. A 2023 study found Red 40 caused DNA damage and promoted colonic inflammation in mice, which is a known risk factor for colorectal cancer.

Allergic Reactions and Sensitivities

Beyond behavioral and carcinogenic risks, red dyes can also trigger allergic reactions or sensitivities in some individuals.

Symptoms of an allergic reaction: Mild allergic responses can manifest as hives, itching, or swelling. More severe cases can lead to anaphylaxis.
Distinguishing from Intolerance: While true IgE-mediated allergies to food coloring are rare, many people experience hypersensitivity or intolerance with similar symptoms, headaches, or gastrointestinal issues.
Carmine as an alternative: Carmine, a red dye from cochineal insects, is sometimes used as a "natural" alternative but can also cause allergic reactions, including respiratory and skin issues.

Natural vs. Synthetic Red Dyes

To make informed decisions, it is helpful to understand the differences in potential hazards between artificial and natural red colorings.


Feature	Synthetic Red Dyes (e.g., Red 40, Red 3)	Natural Red Dyes (e.g., Carmine, Beetroot)
Source	Petroleum distillates or coal tars	Plants (beets, berries) or insects (cochineal)
Associated Health Risks	- Hyperactivity and behavioral issues - Potential cancer links (especially Red 3) - Allergic reactions and sensitivities - DNA damage and inflammation (Red 40 in mice)	- Allergic reactions (especially carmine) - Potential cross-reactivity (e.g., annatto) - Milder or no behavioral links
Vibrancy & Stability	Generally very vibrant and stable in processed foods	Can be less vibrant and stable; may affect flavor
Nutritional Value	None	Often provides additional antioxidants and nutrients

Navigating Product Labels and Reducing Exposure

Avoiding or limiting red dyes requires vigilance when reading product labels. The synthetic dyes are not just in obviously red-colored items. It is crucial to remember that manufacturers can use different names for the same dye.

Key Steps to Reduce Red Dye Exposure:

Read Ingredient Lists: Look for specific names like FD&C Red No. 40, Allura Red AC, FD&C Red No. 3, or Erythrosine.
Beware of "Natural" Labels: Realize that some "natural" dyes, like carmine, can also be allergens.
Choose Whole Foods: Minimize consumption of highly processed and pre-packaged foods where dyes are most common.
Buy Dye-Free: Many brands now offer dye-free versions of products like medications and fruit snacks.
Look for European Products: Because of stricter labeling laws in the EU, many companies produce dye-free versions of products for the European market; these can sometimes be purchased or used as a guide.

Conclusion

The health hazards of red dye, particularly the synthetic varieties like Red 40 and the now-banned Red 3, are well-documented, spanning behavioral issues like hyperactivity in children to potential cancer risks and allergic reactions. Although the long-term effects on humans require more research, the evidence is strong enough that regulatory bodies and consumers are increasingly cautious. Opting for whole foods, reading labels carefully for specific dye names, and choosing dye-free or naturally colored alternatives are practical steps for anyone concerned about these unnecessary food additives. By staying informed, consumers can make safer choices for themselves and their families.

Authoritative Source

Center for Science in the Public Interest: Synthetic Food Dyes: A Rainbow of Risks

Frequently Asked Questions

Red Dye 40 (Allura Red AC) and Red Dye 3 (Erythrosine) are both petroleum-derived synthetic colorants with different chemical properties. Crucially, the FDA banned Red 3 in January 2025 due to strong evidence linking it to cancer in rats, while Red 40 remains on the market, though it carries its own health concerns.

While red dyes are not proven to cause ADHD, multiple studies have established a link between the consumption of synthetic food dyes, including Red 40, and the exacerbation of hyperactivity and other neurobehavioral symptoms in sensitive children.

Red dyes are found in a wide range of processed foods and beverages, including candy, fruit snacks, breakfast cereals, sodas, and baked goods. They are also present in many cosmetics and medications, including certain gummy vitamins and liquid syrups.

Carmine, or cochineal extract, is a red dye derived from insects and is considered 'natural'. However, some individuals can have allergic reactions to carmine, including hives, swelling, and respiratory issues, so it is not risk-free for everyone.

To avoid red dyes, you should always check the ingredient list on packaged products for terms like FD&C Red No. 40, FD&C Red No. 3, or other color additives. Opting for natural, unprocessed whole foods and choosing products with clear 'dye-free' labeling are also effective strategies.

The European Union has more restrictive regulations regarding synthetic food dyes compared to the U.S. In Europe, products containing Red 40 and other dyes must include a warning label about potential effects on children's behavior, leading many manufacturers to use natural alternatives for the European market.

Most food color additives are poorly absorbed by the body and are quickly eliminated. The time it takes for a dye like Red 40 to be excreted depends on an individual's metabolism, but it is typically cleared from the system within a couple of days.