Is Red Dye 40 Still Bad for You? What Recent Studies Say

January 12, 2026 •

3 min read

In early 2025, the FDA announced a plan to phase out synthetic food dyes like Red Dye 40, citing health risks and consumer demand for cleaner ingredients. Despite its long-standing approval, growing research suggests this common food additive may be worse than previously thought, impacting gut health, behavior, and more.

Quick Summary

Despite long-standing FDA approval, recent research in 2024 and 2025 indicates Red Dye 40 may cause gut inflammation and exacerbate behavioral issues, particularly in sensitive children. The dye's continued use is under scrutiny following a similar additive's cancer link, driving a broader regulatory push towards natural alternatives.

Key Points

Recent studies raise concerns: A 2023 study in mice linked Red Dye 40 to gut inflammation and altered microbiomes, a potential risk for long-term health issues like colorectal cancer.
Exacerbates ADHD symptoms: A 2021 review confirmed that Red Dye 40 and other synthetic dyes can worsen neurobehavioral problems, like hyperactivity and inattention, in sensitive children.
Harbors potential carcinogens: The dye can be contaminated with trace amounts of known DNA-damaging substances, including benzene and benzidine.
Regulatory action is underway: In 2025, the FDA announced plans to phase out synthetic dyes like Red Dye 40, following the precedent set by the ban on Red Dye 3.
Natural alternatives are available: Healthier replacements like beet juice and paprika extract are increasingly being used by manufacturers, offering vibrant color without the synthetic risks.
Check your labels: To reduce exposure, consumers should read ingredient lists carefully for "Red 40," "Allura Red AC," or "E129" and choose whole foods or products with natural colorings.

Red Dye 40: A New Era of Scrutiny for a Ubiquitous Additive

Red Dye 40, scientifically known as Allura Red AC, has been widely used in processed foods since the 1970s. While historically considered safe by regulatory bodies like the FDA at typical consumption levels, recent scientific studies and increased consumer awareness have brought its safety under renewed scrutiny.

The Science Has Evolved: What Recent Research Reveals

Newer research explores the long-term, systemic impacts of Red Dye 40, focusing on areas like gut health and neurobehavioral function, rather than just immediate toxicity.

A Closer Look at Recent Findings:

Gut Health and Inflammation: A 2023 study indicated that Red Dye 40 significantly harmed gut health and caused inflammation in mice, potentially increasing the risk of conditions like colorectal cancer.
Neurobehavioral Effects in Children: Recent reviews and studies, including a 2021 report from California, have strengthened the link between synthetic food dyes and hyperactivity and inattention in some children, particularly those with a predisposition. European regulations already require warning labels on products containing the dye.
Concerns over Carcinogenic Contaminants: Analysis shows that Red Dye 40 can contain trace amounts of potentially cancer-causing substances. The ban on the similar Red Dye 3 in 2025 due to a cancer link highlights growing concerns about such contaminants in food additives.

The Regulatory Shift and Voluntary Phase-Out

Following the Red Dye 3 ban, regulatory approaches are changing. In April 2025, the FDA and HHS announced a plan for the voluntary phase-out of several synthetic dyes, including Red Dye 40, by the end of 2026. This initiative is driven by accumulating research, consumer demand, state-level actions, and the availability of natural alternatives.

Natural Alternatives vs. Synthetic Red Dye 40: A Comparison


Feature	Synthetic Red Dye 40 (Allura Red AC)	Natural Red Alternatives (e.g., beet juice, paprika)
Origin	Derived from petroleum.	Derived from fruits, vegetables, and plants.
Cost	Generally cheaper to produce.	Often more expensive to produce and process.
Stability	Very stable, consistent color under varying conditions.	Can be sensitive to heat, light, and pH levels, potentially leading to color degradation.
Flavor Impact	Flavor-neutral.	May impart subtle flavors, though this can sometimes be masked by manufacturers.
Labeling	Labeled as "Red 40," "Red 40 Lake," or "E129".	Labeled by their source, such as "beet juice extract".
Health Concerns	Linked to hyperactivity, inflammation, and potential carcinogenic contaminants.	Considered safer with minimal health risks, and often provide added nutritional benefits.

How to Reduce Red Dye 40 Consumption

Reading ingredient labels is key to reducing Red Dye 40 intake. Be aware it can be listed under names like Allura Red AC or E129. Choosing natural, unprocessed foods is the most direct way to avoid it.

Check Ingredient Lists: Look for "Red 40" or its other names on product labels.
Prioritize Whole Foods: Focus your diet on natural ingredients like fruits, vegetables, and whole grains.
Seek Out Natural Alternatives: Many companies are now using natural colorings like beet juice or paprika extract. Look for these on labels.
Communicate Concerns: If you suspect sensitivity, keep a food diary and consult a healthcare provider. You can also find more information from sources like the California Office of Environmental Health Hazard Assessment.

Conclusion

Recent studies have raised new concerns about Red Dye 40, pointing to potential links with gut inflammation, behavioral issues in children, and carcinogenic contaminants. The 2025 FDA and HHS plan to phase out synthetic dyes signals a shift in regulatory perspective. To minimize potential risks, consumers should prioritize reading labels, opting for whole foods, and choosing products with natural colorings whenever possible. The scientific understanding and regulatory approach to Red Dye 40 are evolving, suggesting it may not be as harmless as once believed.

Frequently Asked Questions

No, Red Dye 40 does not cause ADHD, but recent research, including a 2021 California EPA review, indicates it can worsen existing hyperactivity and inattention symptoms in sensitive children.

No, they are different chemical dyes, though both are petroleum-based. The FDA banned Red Dye 3 in 2025 due to a cancer link in animals, a risk not established for Red Dye 40, though its own safety is under increased scrutiny.

While the FDA has historically maintained that Red Dye 40 is safe, it announced a voluntary phase-out in April 2025. This was in response to growing evidence of health risks and consumer pressure, pushing for a move toward safer, natural alternatives.

Side effects can vary, but potential concerns include exacerbating hyperactivity in sensitive children, triggering allergic reactions like hives, and potentially causing or worsening gut inflammation based on animal studies.

Natural alternatives include beet juice or beet powder, paprika extract, annatto, and hibiscus powder. Many food manufacturers are transitioning to these options to provide cleaner, more natural ingredients.

You can check the ingredient list on product labels. Red Dye 40 may be listed as "Red 40," "FD&C Red No. 40," "Red 40 Lake," "Allura Red AC," or "E129" (in Europe).

For some children who are sensitive to artificial food dyes, eliminating Red Dye 40 from their diet can lead to a reduction in hyperactivity symptoms. Parents may find it helpful to track behavior and discuss diet changes with a pediatrician.