Are synthetic food colors bad for you? Here is the science.

Synthetic food colors—and their links to neurobehavioral issues in children—are having a moment.

Last month, California Gov. Gavin Newsom signed into law the California School Food Safety Act, banning the state’s public schools from serving or selling foods containing six synthetic food colors starting in 2028. More Earlier this month in Michigan, protests erupted outside the Battle Creek headquarters of WK Kellogg Co., as the company drew fresh criticism for its broken commitment to remove synthetic food colors in American products, including cereal.

Meanwhile, the same dyes banned in California are still approved by the US Food and Drug Administration. The agency does not appear to be changing course, saying there is not enough evidence to prove that synthetic dyes cause problems such as ADHD, hyperactivity or lack of focus.

The list of foods that contain synthetic food coloring is long. And fueling the noise is the inability to distinguish the danger that a child has during their consumption. When federal and state guidelines don’t match, it can be tricky to find out which foods contain the colors and whether they should be avoided altogether.

Despite limited evidence of a neurobehavioral link, experts believe that some children may be more susceptible than others. Many experts are convinced that California’s law provides safety for the state’s public school students, and they hope the act could inspire other states to follow suit, forcing food manufacturers to reconfigure their recipes.

“I think it’s a great place to start because school is an environment where children should be able to focus. They need to be able to feel like they’re in control of their bodies,” says Melanie Benesh, vice president of government affairs for the Environmental Working Group in Washington, DC, a nonprofit corporation that sponsored the California School Food Safety Act. “It creates a better learning environment for everyone.”

Amidst this national conversation, Scientific news looked at how we got to this point and what science has to say about consuming synthetic food dyes.

What are synthetic food colors and why are they in our food?

Synthetic colors add color to food. Each of them has a unique molecular structure that absorbs specific frequencies of light, allowing people to perceive a rainbow of colors in soft foods. Beyond adding a splash of color, synthetic dyes are essentially useless. They do not help preserve food or add any nutritional value; their job is to seduce.

“A lot of these foods are candy, cereal—things that are marketed to kids,” Benesh says. When manufacturers use synthetic dye, it “makes their food more brightly colored, more attractive to children, and I think it helps them sell their products.”

Which products have synthetic dyes?

Foods with synthetic colors are not packaged with a warning label in the United States, so analyzing individual product labels is usually the only way to decipher exactly which food items contain which colors. If present, synthetic colors will be listed in the fine print of an item’s ingredient list, usually as the name of a color followed by a number (such as “Yellow 5”). If you’re looking to avoid dyes, here are some grocery store staples to watch out for:

• Baked goods such as cake mix, sugar cookies and gingerbread
• Snacks like Pop-Tarts, Cheetos and even some dried fruit
• Candies such as M&M’s, Skittles and Nerds
• Cereals such as Froot Loops, Trix and Lucky Charms
• Beverages and specialty drinks such as Electrolit, Pedialyte and Powerade

It is not only food products that contain synthetic food colors. Some eyeshadows, hair products and medications contain some of the dyes now banned in California.

When did scientists realize that synthetic dyes could be harmful?

Synthetic dyes have a long and troubled history. Lead chromate, arsenic, and additives made from coal tar were some of the first iterations, dealing a poisonous blow to consumers in the 19th and 20th centuries. In 1950, dozens of children became ill after consuming tainted Halloween candy with a dangerous color, Orange 1 (SN: 8/12/11).

Many modern synthetic dyes were invented at the same time; five of the six dyes banned in California were approved by the FDA in 1931. But their potential for harm was not widely discussed until the mid-1970s, when the idea of ​​a possible link between food coloring and childhood hyperactivity was discovered in public. says Mari Golub, a developmental neurotoxicologist at the University of California, Davis. A flurry of research ensued, but the FDA stuck to their guidelines.

However, some scientists say the connections are obvious. Over the past 50 years or so, a growing body of scientific research and anecdotal evidence has pointed to a link between certain synthetic food colors and neurobehavioral issues in children, which can manifest as mood swings, hyperactivity, and lack of attention. the focus.

So why did California ban the six synthetic dyes?

In 2021, California’s Office of Environmental Health Risk Assessment released a report that would help push the state to ban Blue 1, Blue 2, Green 3, Red 40, Yellow 5 and Yellow 6 in public schools .

The report’s authors looked at available research that investigated how synthetic food dyes affect children. They analyzed 25 clinical trial studies that compared periods of time when groups of children consumed foods colored with synthetic dyes to periods when they ate a placebo. In many of the trials, parents and teachers noticed any behavior problems when they appeared. The report’s authors ultimately wrote that 16 of the studies showed a reliable link between behavioral outcomes and a child’s consumption of synthetic dyes.

But discovering a link doesn’t mean scientists can confirm that synthetic dyes are the direct cause of neurobehavioral issues. This is where animal studies come in.

Randomized studies with mice, rats, and rabbits have shown a clearer link between individual synthetic food dyes and neurobehavioral effects. Some animals exposed to synthetic dyes, such as those banned, can become hyperactive or show signs of memory loss.

While animal studies can be important tools for comparison, the amount of food coloring given to lab rats is difficult to compare with, say, how many Red 40 sprinkles are on a cupcake. It is difficult to count the individual sprinkles, chips and cookies in a child’s diet.

But animal studies have shown that colors affect animals neurologically, and they can help scientists determine which colors and individual doses start to create adverse effects, says Mark Miller, a pediatric environmental health physician at the California Office of Assessment of Environmental Health Hazards in Oakland, who worked. on assessment.

Why was the California decision controversial?

Not everyone supports California’s ban.

“Consistency in food regulations across states and federal agencies is critical to ensuring public confidence,” says Sean Taylor, an organic and biological chemist with the International Color Manufacturers Association in Washington, DC. He notes that the FDA reviewed scientific literature like Golub’s. the team did and concluded that there was no causal relationship between children consuming synthetic dyes and unwanted behaviors.

It’s hard to be specific when talking about the danger of food dyes because there isn’t much research out there to begin with. And technically, the FDA and the 2021 California Health Assessment don’t contradict each other: It finds no causal relationship; the latter finds an associative link.

Because there has not been a study comparing one group of children on a diet without food dyes to another group of children consuming food concentrated with individual doses of synthetic dyes, it is difficult to identify a causal relationship.

“We don’t have the kind of data that would be the gold standard causal data,” says Amy Gilson, Deputy Director of External and Legislative Affairs at the California Office of Environmental Health Risk Assessment in Sacramento. It is unlikely that a black and white study will ever be published. But, says Gilson, “you don’t need to have all the causal data that someone would want to say, ‘Hey, you know there’s good evidence here. There is good science that tells us we need to take some action.’