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Public Health Professor Shows Food Dye Linked to Neurological Childhood Development in California EPA Study

April 16, 2021
Public health Professor Asa Bradman conducted research to examine a link between childhood development and food dyes. Photo by Veronica Adrover, UC Merced
Public health Professor Asa Bradman conducted research to examine a link between childhood development and food dyes. Photo by Veronica Adrover, UC Merced

Public health Professor Asa Bradman contributed to a new report that examines the relationship between synthetic food dye — found in everything from juice to cupcakes — and child development.

The report, released today by the California Environmental Protection Agency’s Office of Environmental Health Hazard Assessment (OEHHA), finds that current federal levels for safe intake of synthetic food dyes may not sufficiently protect children’s behavioral health.

“This is the most comprehensive study examining dietary exposure to artificial food coloring in vulnerable populations such as young children and pregnant women. We found that children tended to have higher exposures than adults, and some exposures might exceed regulatory guidelines,” Bradman said. “We also observed higher exposures in lower-income populations, pointing to the need to improve consumption of, and access to, healthier food.”

The report is the product of a two-year, multifaceted evaluation of seven synthetic food dyes that have been approved by the FDA. OEHHA extensively reviewed existing studies of the effects of these dyes on both humans and laboratory animals.

The percentage of American children and adolescents diagnosed with attention deficit/hyperactivity disorder (ADHD) has increased from an estimated 6.1% to 10.2% during the past 20 years. Concerns about increasing rates of ADHD and other behavioral disorders prompted the California Legislature to ask OEHHA to conduct the food dye assessment.

“Evidence shows that synthetic food dyes are associated with adverse neurobehavioral outcomes in some children,” said OEHHA Director Lauren Zeise. “With increasing numbers of U.S. children diagnosed with behavioral disorders, this assessment can inform efforts to protect children from exposures that may exacerbate behavioral problems.”

OEHHA evaluated old and new research and then applied modern risk assessment methods to interpret the findings. The risk assessment evaluated studies that placed children on a dye-free diet for several weeks and measured their behavior. The children were given food or drinks with dyes added, and measures of their behavior were recorded by a number of standardized methods. These studies demonstrated that some children are likely to be more adversely affected by synthetic food dyes than others. Animal studies indicate synthetic food dyes affect activity, memory and learning, cause changes in the neurotransmitters in the brain and cause microscopic changes in brain structure.

The OEHHA findings reveal that consumption of synthetic food dyes can result in hyperactivity and other neurobehavioral problems in some children, and that children vary in their sensitivity to synthetic food dyes.

According to the OEHHA, approved levels of synthetic food dyes were established by the Food and Drug Administration decades ago and do not reflect newer research. The FDA’s Acceptable Daily Intake levels (ADIs) for synthetic food dyes are based on 35- to 70-year-old studies that were not designed to detect the types of behavioral effects that have been observed in children, according to the OEHHA. Comparisons with newer studies indicate that the current ADIs may not adequately protect children from behavioral effects.

The study is a result of OEHHA’s collaboration with Bradman and scientists at UC Berkeley and UC Davis. The research team found that children are exposed to multiple dyes in a day, and that the highest exposures are usually from juice drinks and soft drinks. They also found that common exposures to Red Dye No. 3 from a few foods may exceed the existing ADI.

If revised ADIs for some of the dyes were based on newer studies, updated acceptable intake levels would be much lower.

OEHHA began the study by inviting the public to submit scientific information on the health effects of synthetic food dyes. It conducted a two-day symposium in September 2019 to foster discussion among researchers in academia, industry, government and the public on potential effects of synthetic food dyes on children. A draft version of the report was released in August 2020 for comment by members of the public and external peer review by experts identified by the University of California Office of the President.