Are artificial food dyes really safe? What's the link between food dyes and ADHD?
"So many foods include artificial colors, like yellow 5 lake; red 40 lake, blue 1, and so on. I have heard from several people that artificial red dyes are the worst. What makes them the worst? Are they really bad for you?"
If you start reading ingredient lists, you might surprised to see how many foods have added colorings. I’m not just talking about rainbow-colored cereals or other garishly tinted items. I’m talking about things like yogurt, cheese, gravy, and crackers—foods that don't look colored at all. For example, a blue dye might be added to make white frosting look whiter.
The synthetic dyes approved by the FDA for use in foods are identified by number, as in "Yellow No. 5" or "Blue No. 1." The word "lake" indicates that the dye has been mixed with a mineral salt to make it insoluble in water. The straight dyes are generally used in drinks and other liquids. The lake colors are used in baking and other solid foods.
Why are colors added to foods?
Although we may think we don’t want anything unnatural in our food, studies of consumer preference repeatedly show that foods enhanced with synthetic colors are more appealing than foods made without coloring or made with natural colorants.
The color actually affects how we perceive the taste. The macaroni-and-cheese made with yellow dye tastiest creamier and cheesier than the all-natural brand with no coloring added.
Synthetic colors tend to be a lot more stable and—ironically—better at making food look the we think it should look. And all of the the colorings approved by the FDA for use in food manufacturing have been thoroughly evaluated for safety.
Nonetheless, artificial food colors have a bad reputation. In particular, there are persistent concerns that they may cause (or exacerbate) hyperactivity or ADHD in kids.
Does food coloring make kids hyper?
The idea that food colorings might be linked to hyperactivity in kids dates back to the 1970s, when a pediatrician named Ben Feingold proposed a diet that eliminated all artificial colorings and preservatives as a treatment for hyperactivity. He claimed that this protocol was highly effective in reducing symptoms. Other experts have questioned his results, claiming that when kids didn’t do well on the diet, he simply excluded those cases from his data.
What’s the evidence on artificial dyes and hyperactivity?
Nonetheless, Dr. Feingold’s hypothesis spurred others to research the question. It turns out that this is a tricky subject to study. Measuring the level of hyperactivity in a child is essentially a subjective judgment, and it turns out that the results depend a lot on who is doing the rating. For example, it seems that parents are more likely to rate their children’s behavior as hyperactive than teachers or clinicians are. Not surprisingly, their expectations also color their judgments. When parents think their kids have been given food additives, they tend to perceive an increase in hyperactive behavior—whether or not the kids actually did ingest them.
I once heard an interview with a mom who claimed that she could tell which artificial colors her child had eaten based on his behavior. Red dye made him aggressive and hostile, she said. Blue, on the other hand, made him weepy and sad. Notice that the associations she observed line up exactly with common idioms. When people are angry, we often say they are “seeing red.” And when we’re depressed, we say we are “feeling blue.” It’s a pretty striking coincidence.
Even if you only look at double-blind, placebo-controlled studies—the so called gold standard of research design—the results are inconsistent, to say the least. Some have found that food colorings seemed to increase hyperactive behavior. Many found no relationship. And a few even found that food coloring seemed to decrease hyperactive behavior.
Should synthetic food dyes be removed from the food supply?
Ten years ago, in response to a petition from the Center for Science in the Public Interest, an FDA committee held hearings to decide whether to recommend changing the rules for these ingredients. The committee concluded that there was not enough evidence to warrant banning these ingredients—or even including a warning on foods that contain them.
More recently, in 2018, the state of California commissioned a new review of the evidence on the potential neurobehavioral effects of synthetic food dyes in children, from California’s Environmental Protection Agency. This report included the evidence reviewed by the FDA in 2011 along with some newer studies.
The researchers point out that while “inherited factors may put individual children at risk for ADHD, at least some of the risk in susceptible children is likely the result of these inherited factors interacting with exposures to substances in the environment, including foods.”
The reviewers also acknowledge that some studies found no clear association and that it appears that children vary greatly in their sensitivity to these additives. But, in the end, they found convincing evidence that synthetic food dyes may be associated with inattentiveness, hyperactivity, and restlessness in sensitive children.
As for Courtney’s question about whether red food dye is any worse than the others, it’s a little hard to say. Most of the studies use a cocktail containing several different food dyes.So even when a link has been detected, there’s no way to know which of the several chemicals might be responsible. But I’m not aware of any evidence that red dye is any worse than any of the others.
4 things parents need to know about food dyes and hyperactivity
- Food dyes aren’t a problem for most kids. Some kids, however, appear to be especially sensitive to the additives. For these children, avoiding foods with artificial colorings may be helpful. (If you’re trying to avoid synthetic dyes, keep in mind that they are often used in children’s medications as well.)
- Eliminating food dyes may not completely solve the problem. ADHD usually has many contributing factors. If your child is sensitive to food dyes, avoiding them may help but will probably be only one part of the solution.
- A healthy diet is low in food dyes, anyway. The primary sources of food dyes are brightly colored candy, breakfast cereals, sweetened beverages, and other processed foods. Even if the FDA did require manufacturers to take the artificial colorings out of these foods, you still wouldn’t want your kids eating that stuff in large quantities. The easiest way to minimize your child’s exposure to synthetic dyes is to limit his consumption of these foods. That will also improve the nutritional quality of your child’s diet—which is also likely to have a positive impact on learning, mood, and behavior.
- Don’t sweat the small stuff. Eliminating every trace of artificial coloring from your child’s diet would be a very tough job. Fortunately, this is not like a peanut allergy where the smallest particle of peanut could bring on a life-threatening reaction. In some of these studies, for example, the amount of food dye that was linked to behavior change was the equivalent of an 8-year-old eating a half pound of candy in a single sitting. The same behavior changes were not seen at lower amounts.
Here’s the bottom line: Food dyes may be related to behavior changes in some kids. But when looking at population wide effects, the connections don’t seem strong enough to spur governmental action. Which leaves parents who suspect that their kids may be sensitive to take evasive action.