It was Trenton Shutters’ first week at preschool when the typically easy-going 4-year-old took an alarming turn for the worst.

“He started melting down several times a week and was unable to recover,” recalls Trenton’s mom, Renee Shutters. “One day he’d be fine, the next he would get angry and not like himself. We thought he was bipolar. I was scared.”

After months of trying to pinpoint a trigger, Trenton’s mother and teacher drew an intriguing conclusion: On days Trenton had orange cheese puffs, blue sugar-free yogurt, or the other colorful fare often provided for snack at school, his attention cratered. And on the nights when his mom gave in and let him have a neon gumball at hockey practice, a temper tantrum was sure to ensue. Skeptically, Renee took the advice of a friend, purged her cupboard of anything containing artificial food color, and asked his teachers to keep him away from dyes as well.

 “We saw an improvement within days,” says Shutters, who lives in Jamestown, New York. “Trenton is a model student now.”

Shutters is among dozens of parents, physicians and researchers who will converge on Washington, DC March 30 and 31 to urge a U.S. Food and Drug Administration (FDA) panel to recommend a ban of—or at least warning labels on—foods containing synthetic dyes.

Their allegation—that the petroleum-based colorants can lead to behavior problems, allergies and possibly cancer—dates back to the 1960s, when San Francisco allergist Ben Feingold reported that his patients’ radically improved when they kicked dyes. With few legitimate studies verifying the link, Feingold’s theories were largely dismissed. But thanks to a series of highly respected European trials connecting dyes to attention disorders, the European Parliament moved in 2010 to require warning labels on foods that contain them. Now U.S. regulators are taking a fresh look at artificial colors and their potential health hazards as well.

“Just the fact that FDA is holding this hearing is very significant,” says Michael Jacobson, executive director of the Center for Science in the Public Interest (CSPI), which called for the meeting. “It sends a message that this is a topic worthy of discussion.”

Appetite for neon

According to the FDA, Americans ingest five times as much synthetic dye (roughly 60 mg daily) today than they did in 1955, with 15 million pounds consumed in 2009 alone. Vivid blues, reds, greens, oranges and yellows serve to lure picky consumers (often kids) in a competitive food market, and often impersonate “real food.” Case in point: General Mills’ Total Blueberry Pomegranate Cereal actually contains no blueberries or pomegranates, and instead uses Red #40 and Blue #2 to mimic the presence of the colorful fruit.

But food scientists note that color also plays a more practical role, restoring hues lost or muted in the manufacturing process, or turning naturally brown and gray concoctions into something more appealing to the modern eye.

 “Without added color, some of these foods would look unappetizing,” explains Leslie Lynch, a sales manager at Food Ingredient Solutions LLC, which formulates natural food colors.

A history of dangerous dyes

Food companies have been using artificial colors to make food more appealing for centuries. In the 1800s, an array of lethal compounds, including copper sulfate, lead chromate and arsenic were used. Colors made from coal tar (also used to dye clothing) became the norm by the 1900s.

But over the years, following reports of children being poisoned and rodents developing reproductive tumors, hundreds of artificial colors were banned,  including Violet #1 (once used in the U.S. Department of Agriculture’s own meat inspection stamp) and Red #2 (which is still allowed to be used in the coloring of orange peels).

Today, nine petroleum-based dyes have been tested and approved for use in food, and each batch must be pre-screened by the FDA—a fact that many see as a testament to their safety.

“There are a lot of things out there that people consume that the FDA doesn’t oversee at all,” notes Bonnie Jortberg, a registered dietitian with the University of Colorado School of Medicine. “I haven’t seen anything in the literature that would lead me to believe there should be great concern about food dyes.”

A culprit in hyperactivity?

Although the body of evidence may not be large, a few well-designed studies have swayed entire governments, and even the American Academy of Pediatrics (AAP), to reconsider the health effects of artificial food colors.

In 2004, David Schab published a groundbreaking meta-analysis looking at three decades worth of research on food dyes and hyperactivity in children.

At first, skepticism fueled his interest. “There were a lot of really poorly conducted studies out there that concluded with unconvincing and over-reaching claims,” recalls Schab, PhD, an assistant clinical professor of psychiatry at Columbia University. But once he weeded out the bad studies, “Artificial food colorings appeared, in the highest quality of studies, to promote behavioral disturbances in hyperactive children,” Schab says.

According to the researcher, the mechanism by which synthetic dyes impact behavior remains unclear, but they likely interfere with transmission of the neurotransmitter dopamine, which plays a critical role in attention.

Another lingering question: Do they impact only a certain subset of children, already prone to hyperactivity, or are all kids at risk?

Schab believes that question was answered by researchers at the University of Southhampton in the United Kingdom. They administered either an artificially colored drink or a dye-free alternative to 153 3-year-olds and 144 8-year-olds after they had stripped dyes from their diet for six weeks. Assessments from parents and teachers showed “significantly higher hyperactivity scores” in kids within hours after consuming the colored drinks.

In a 2007 study published in the Lancet, the University of Southhampton researchers concluded that “the adverse effects are not just seen in children with extreme hyperactivity but can also be seen in the general population.”

The study was not without flaws. For example, it used six colors and a preservative called sodium benzoate—making it impossible to isolate which compound was to blame.

Nonetheless, the American Academy of Pediatrics released a statement soon after suggesting that “a trial of a preservative-free, food coloring-free diet is a reasonable intervention,” for kids with hyperactivity problems. An accompanying AAP editorial added: “We skeptics might have been wrong.”

Government action: U.S. vs. U.K.

In the U.K., the European Parliament asked food manufacturers to voluntarily remove synthetic dyes from food by Dec. 31, 2009. In what many see as a de-facto ban, it now requires foods containing them to sport a damning label: “May have an adverse effect on activity and attention in children.”

Australia and Canada are now considering similar moves and at least one U.S. state, Maryland, has proposed a ban on food dyes in school lunches.

Meanwhile, parents in the United States are feeling snubbed. “There are people out there who will never even suspect this—who will never know what’s wrong with their children,” says Shutters, who was the first to sign up for the FDA hearing. “Our government needs to protect our kids too.”

And it’s not just the governments that are behaving differently on the issue of dyes. Responding to consumer pressure and the U.K.’s labeling laws, numerous multi-conglomerate food companies, including Mars Inc. and Kraft Foods Inc., have removed artificial colors from their products sold in Britain—while still selling those same synthetically colored products in America.

Allergies, cancer and missing out on real food

Representatives from the Grocery Manufacturers Association maintain that “the safety of both artificial and natural colors has been affirmed through extensive review.”

But CSPI’s Jacobson argues that many of the studies used to draw that conclusion were conducted by industry and are potentially biased. A 2010 CSPI report suggests that the three most commonly used dyes—Red 40, Yellow 5 and Yellow 6—are often contaminated with known carcinogens. The report also shines a light on animal studies that suggest some artificial colors promote tumor growth. Meanwhile, Blue 1, Red 40, Yellow 5 and Yellow 6 have all been shown to cause allergic reactions in sensitive populations.  Yellow 5—Tartrazine—has been shown to cause hives and asthma in as many as 26 percent of people with allergies.

Pediatrician Alan Greene, MD, says he too has concerns about behavioral and other impacts of dyes, and always steers kids away from them. But he sees an even more insidious impact of our ever-increasing appetite for artificially colored food.

“We are designed to be attracted to colorful foods so that we are led to ripe fruits and vegetables and other things that are good for us,” Greene says. “Food companies have learned that they can draw our attention away from those healthy foods by making unhealthy foods look colorful. We need to stop falling for it.”

Connect with writer Lisa Marshall at lisamarshall08@gmail.com.