Health Concerns of Blue No. 2 Food Dye
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The Health Dangers of Food Dye Blue No. 2

The Health Dangers of Food Dye Blue No. 2
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Updated on September 27, 2025
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The U.S. Food and Drug Administration (FDA) currently lists seven primary color additives approved for use in foods. These artificial food colorings are called “FD&C” color additives because they are approved for use in food, drugs, and cosmetics.

Artificial food colorings have been linked to behavior changes in children, as well as other pediatric health concerns, including a predisposition to cancer, allergies, gastrointestinal and respiratory problems, and more, according to a study.

 These findings have sparked public concern, as the dyes are widely used in foods such as cereals and candies that are marketed to children.

Background

Dollar bills

Food manufacturers use synthetic dyes mainly for product and formula development.

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Food manufacturers use synthetic dyes mainly for product or formula development reasons, according to the FDA. The dyes protect against color loss, even out natural variations in food color, and make “fun foods” colorful and more visually appealing. Food dyes also help products match our expectations. For instance, manufacturers dye strawberry ice cream pink and mint ice cream green.


Blue No. 2

Close Crop of Child Eating Rainbow Ice Cream Cone
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FD&C Blue No. 2 is also called indigo blue or indigotine. It is a synthetic version of indigo, a dye naturally produced from plants. Indigotine is distinguished by a rich royal-blue color, and it is currently used for coloring foods and drugs, says the International Association of Color Manufacturers.


Hyperactivity in Children

Boy (6-7) pulling girl's (4-5) hair in room

Hyperactivity in children.

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A review indicated that there's limited research on artificial blue food colorings causing symptoms of attention-deficit hyperactivity disorder (ADHD) in children. It was stated that more research is needed to fully determine the neurotoxicity, or nervous system damage, of artificial blue dyes in humans.

That said, a study demonstrated that color additives including FD&C Blue No. 2 are linked to a number of health problems that disproportionately affect children. These include behavioral changes in children both with and without diagnosed disorders. The pediatric populations analyzed in the study included children diagnosed with autism and ADHD, as well as children without behavioral disorders.

It is important to note that the limitations of studies on the effects of synthetic dyes can vary widely. One limitation is the lack of comprehensive, specific research on the long-term effects of these dyes across different populations, especially in children and individuals with food sensitivities.

Also, there are so many different synthetic dyes used in the food industry that it's difficult to apply the study results broadly. Not to mention, researchers may not always use the same methods to measure results. Another common challenge is separating the impact of synthetic dyes from other ingredients within the food, which makes it harder to clearly pinpoint cause and effect

What’s more, the influence of individual factors, such as diet and lifestyle, is often not fully controlled in studies, which can affect the interpretation of results. These limitations highlight the need for a more comprehensive and rigorous approach when investigating the effects of synthetic dyes on human health.

EDITORIAL SOURCES
Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.
Resources
  1. Summary of Color Additives for Use in the United States in Foods, Drugs, Cosmetics, and Medical Devices. U.S. Food and Drug Administration. December 16, 2025.
  2. Oliveira ZB et al. Synthetic Colors in Food: A Warning for Children’s Health. International Journal of Environmental Research and Public Health. May 27, 2024.
  3. HHS, FDA to Phase Out Petroleum-Based Synthetic Dyes in Nation’s Food Supply. U.S. Food and Drug Administration. April 22, 2025.
  4. Indigotine.  International Association of Color Manufacturers.
  5. Rambler RM et al. A Review of the Association of Blue Food Coloring With Attention Deficit Hyperactivity Disorder Symptoms in Children. Cureus. September 16, 2022.
Additional Sources
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Sylvia Klinger, DBA, MS, RD, CPT, is an internationally recognized nutrition expert who is relentlessly passionate about helping people fall in love with creating and enjoying delicious, safe, and nutritious foods.

As a food and nutrition communications professional, Dr. Klinger is a global nutrition professor, award-winning author, and the founder of Hispanic Food Communications.

She is on the board at Global Rise to build a formal community nutrition program as part of an ambitious initiative to create a regenerative food system in Uganda in partnership with tribal and community leaders. This program included an extensive training session on food safety and sanitation that displayed cultural sensitivity and various communication strategies and incentives to spread these important food safety and sanitation messages into the communities.

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