The History & Controversy of Red Dye No. 40

The History & Controversy of Red Dye No. 40

A History of Red Dye No. 40

Red Dye No. 40 is a synthetic dye that's found in a wide array of products, from the brightly colored candies and cereals that line grocery store shelves to cosmetics, medications, and even children's toys1. It's one of the most commonly used dyes in the United States, adding that vibrant red hue to countless foods and beverages we consume every day2. But where did this dye come from, and how did it become so prevalent? Let's delve into the history of Red Dye No. 40, exploring its invention, FDA approval, controversies, and potential health effects.

Invention and Early Use

Red Dye No. 40, also known as Allura Red AC or FD&C Red 40, was developed in 1971 by the Allied Chemical Corporation3. It was originally introduced as a replacement for amaranth (FD&C Red No. 2) in the United States3. Amaranth was another red dye that was ultimately banned in 1976 due to health concerns4. 

The red dye called amaranth should not be confused with the natural plant also called amaranth. While the specific motivations behind the development of Red Dye No. 40 aren't explicitly understood, it was likely intended as a safer and more stable alternative to amaranth for use in food products. As with many products in the food supply, the intention was likely good, but the unintended consequences not so much.

Patent Information

Unfortunately, the specific patent information for Red Dye No. 40 is not available in the provided research material. While some sources mention patents related to food coloring compositions containing Red Dye No. 405 they don't provide details about the original patent for the dye itself. Further research might be needed to uncover this information. IT may be that the original chemical company chose to keep the formula as a trade secret, rather than publish it as a patent and allow the public to see the methods and ingredients.

FDA Approval

Red Dye No. 40 was approved for use in the United States by the Food and Drug Administration (FDA) in 19716. The FDA's color additive regulations, established through the Color Additive Amendments of 1960, require that all color additives used in food, drugs, and cosmetics be demonstrated as "suitable and safe" for their intended use7.

Color Additive Regulations

The 1960 Color Additive Amendments also prescribed the factors that the FDA must consider when determining the safety of a proposed color additive, as well as the specific conditions for safe use that must be included in the listing regulation7. In response to these amendments, the FDA updated its procedural regulations for the petition process, ensuring a more rigorous evaluation of color additives before they are approved for use in consumer products7.


While the specific reasons for the FDA's approval of Red Dye No. 40 are not detailed in the provided material, it can be inferred that the dye met the FDA's safety standards at the time of its approval.

Historical Context and Controversies

The use of Red Dye No. 40 has been surrounded by some controversy over the years. In 2007, a study known as the Southampton Study suggested a possible link between certain artificial food dyes, including Red Dye No. 40, and hyperactivity in children8. This study led to increased scrutiny of the dye and calls for warning labels on products containing it.


In the European Union, legislation now requires warning labels on foods containing Red Dye No. 40 and other dyes that were implicated in the Southampton Study8. This legislation aims to inform consumers about the potential for these dyes to have an adverse effect on activity and attention in children, allowing them to make informed choices about the products they purchase8.


The concerns raised by the Southampton Study also prompted Viveri Food Colors, a division of the Day-Glo Corporation, to launch the "Natural Red Food Color Challenge." 8 This challenge offered a $100,000 prize for the development of a clean, safe, and natural alternative to Red Dye No. 40, highlighting the growing interest in finding replacements for synthetic food dyes8.


Despite these concerns, the FDA convened a meeting of its food advisors in 2011 to review the safety of Red Dye No. 40 and other synthetic dyes. The panel ultimately voted against issuing a warning similar to the one in Europe, concluding that the studies had not definitively proven a causal link between the dyes and hyperactivity9. However, the debate continues, and some researchers and consumer advocacy groups still advocate for stricter regulations and more research on the potential health effects of Red Dye No. 409.


There have been other health concerns noted with the use of Red Dye No. 40. Yes, there is evidence in the peer-reviewed literature suggesting that Red Dye 40 (also known as Allura Red AC) may cause health issues. Several studies have highlighted potential concerns:

Chemical Composition and Properties

Red Dye No. 40 is now mostly synthesized from petroleum9. Further chemical reactions are used to combine the dye with aluminum, creating what's known as "Red 40 Lake." 9 Red 40 Lake is often used in products like chewing gum, where there isn't enough moisture to dissolve the dye, or in frostings to prevent the colors from bleeding9. Even white marshmallows have Blue No. 1.


Red Dye No. 40 is a synthetic dye created through a chemical process. It is manufactured by coupling diazotized 5-amino-4-methoxy-2-toluenesulfonic acid with 6-hydroxy-2-naphthalene sulfonic acid in an azo coupling reaction. Over 30 companies are currently producing this dye and most of it is made in the USA. It is the most commonly used food dye in our food supply.


There are more than 36,000 food items sold that contain Red 40.


To better understand the chemical composition and properties of Red Dye No. 40, let's look at the following table:

Property

Value

Source

Chemical Formula

C18H14N2Na2O8S2

10

Type

Coal-tar-derived azo dye

4

Appearance

Dark red powder or granules

11

Solubility

Water-soluble

6

Melting Point (in water)

0 degrees Celsius

12

Boiling Point (in water)

100 degrees Celsius

12

Potential Health Effects

While Red Dye No. 40 is generally considered safe for consumption by regulatory agencies like the FDA, some studies have raised concerns about its potential health effects13. These concerns primarily revolve around behavioral changes in children, allergic reactions, and the potential for triggering migraines.

Hyperactivity and ADHD

However, it's important to note that the research on this link is ongoing and not fully conclusive15. The effects of Red Dye No. 40, if any, seem to be more pronounced in children with ADHD14.

Some studies have suggested a link between Red Dye No. 40 and hyperactivity in children, particularly those with ADHD14. These studies indicate that the dye might trigger or worsen behavioral changes in sensitive children, potentially leading to increased hyperactivity, irritability, and difficulty focusing14. Several studies have linked Red Dye 40 to hyperactivity and ADHD symptoms in children:


  • A 2021 California state report concluded that synthetic food dyes, including Red 40, can cause hyperactivity and other neurobehavioral issues in children. This was a comprehensive evaluation of available studies at the time. This was reported by the California Office of Environmental Health Hazard Assessment. 27 human clinical trials were included along with many preclinical, or animal, studies. The basic conclusion was that the FDA’s “safe levels” were probably not really safe for children. In Europe, since 2010, a warning label is required. Red No. 3 is especially harmful.
  • The American Academy of Pediatrics acknowledged in 2019 that some children may experience behavioral changes or allergic reactions to artificial food colors like Red 40.

Allergies

Red Dye No. 40 has also been implicated in allergic reactions in some individuals16. These reactions can manifest as itching, hives, and in more severe cases, even throat closures16. While allergic reactions to Red Dye No. 40 are considered rare, it's essential to be aware of this possibility, especially if you or your child have known sensitivities to food additives.

Migraines

Some individuals have reported experiencing migraines after consuming products containing Red Dye No. 4017. While the exact mechanism behind this is not fully understood, it's thought that the dye may trigger migraines in those who are susceptible to them.

DNA Damage and Cancer Risk

A 2023 study published in PLOS One found that Red 40 causes DNA damage both in vitro and in vivo. The researchers concluded that Red 40 is a "dangerous compound that dysregulates key players involved in the development of early-onset colorectal cancer".

Other Potential Effects

In addition to the concerns mentioned above, some studies have suggested possible links between Red Dye No. 40 and other health issues, such as irritability, depression, and gastrointestinal problems1. However, more research is needed to confirm these links and understand the potential long-term effects of Red Dye No. 40 consumption.


A 2022 study in Nature Communications showed that chronic exposure to Allura Red AC exacerbated experimental colitis in mice. The researchers found that long-term exposure:


  • Induced mild colitis

  • Elevated colonic serotonin levels

  • Impaired epithelial barrier function

  • Altered gut microbiota composition

  • A review article published in 2013 found that Red 40, along with two other dyes, has been contaminated with benzidine or other carcinogens.

  • Some studies suggest Red 40 may impact gut health by altering serotonin levels and promoting inflammation.

Ongoing Research and Debates

Research on the potential health effects of Red Dye No. 40 is ongoing. Recent studies have investigated the dye's impact on DNA damage, the microbiome, and colonic inflammation in mice18. These studies suggest that Red Dye No. 40 may have some adverse effects, but more research is needed to understand the implications for human health19.

One study found that Red Dye No. 40 can damage DNA both in vitro and in vivo18. Another study showed that long-term consumption of Red Dye No. 40 in conjunction with a high-fat diet led to changes in the gut microbiome and low-grade inflammation in the colon of mice20. These findings raise concerns about the potential long-term effects of Red Dye No. 40 consumption, particularly in combination with other dietary factors.

The debate over the safety of Red Dye No. 40 continues, with some researchers and consumer advocates calling for stricter regulations and more research, while others maintain that the current evidence does not warrant significant concern9. The research on Red Dye No. 40's health effects is ongoing and inconclusive, with varying opinions on the strength of the evidence and the need for regulatory action2.

Alternatives to Red Dye No. 40

Given the concerns surrounding Red Dye No. 40 and other synthetic food dyes, there's a growing interest in finding natural alternatives. Some companies have already started using natural colorants derived from fruits, vegetables, and other sources to replace synthetic dyes in their products. These natural alternatives offer a potentially safer and healthier way to achieve vibrant colors in food and beverages.

Conclusion

Red Dye No. 40 has a long and complex history, from its invention as a replacement for another controversial dye to its widespread use in various food products. While it is generally considered safe by regulatory agencies like the FDA and the EFSA, concerns about its potential health effects, particularly in children, persist1. Ongoing research continues to explore its impact on human health, focusing on areas such as DNA damage, gut health, and behavioral changes.

Despite the controversies, Red Dye No. 40 remains a widely used and approved food coloring agent1. However, the increasing demand for natural alternatives and the ongoing research into its potential health effects may shape the future of this dye. As consumers, it's important to stay informed about the ongoing debate and make conscious choices about the foods we consume.
Dr. Meredith Warner, Orthopedic Surgeon

ABOUT THE AUTHOR

Dr. Meredith Warner is the creator of Well Theory and The Healing Sole. She is a board-certified Orthopedic Surgeon and Air Force Veteran.


She is on a mission to disrupt traditional medicine practices and promote betterment physically, spiritually and mentally to many more people. She advocates for wellness and functional health over big pharma so more people can age vibrantly with more function and less pain.


At Well Theory, Our surgeon-designed products are FDA Registered and formulated to help people:


  • Manage the symptoms of musculoskeletal pain
  • Recover vibrantly from orthopedic related surgeries
  • Fill the gaps in our daily diets
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