Colour Us Worried

Why Synthetic Food dyes should be banned

By Michael F. Jacobson and Sarah Kobylewski

What do Triscuit Roasted Tomato & Olive Oil 100% Whole Grain Crackers, Dole Lots-o-Cherries Fruit Salad Bowls, and Pillsbury Grands! Crescents have in common?

They’re three of the thousands of foods that are dyed with synthetic food colourings to make them look more appetizing.

Shoppers in the United States know that the crackers contain the yellow dye tartrazine, the fruit salad is made with the red dye erythrosine, and the crescents have tartrazine plus allura red dye. Why do U.S. shoppers know? Because the dyes must be listed on the labels along with the foods’ other ingredients. But Canadian consumers are in the dark. Companies here are only required to list “colours.” They don’t typically have to specify which colours, or even whether the colours are natural or synthetic.

Earlier this year, Health Canada proposed requiring that food companies list individual dyes on their labels. While that’s useful, it’s hardly sufficient. Here’s why.

Synthetic food colourings are manufactured from petroleum. Food companies like them because they’re cheaper, more stable, and brighter than natural colourings like paprika, beet or blueberry juice concentrate, and beta carotene.

Considering the proliferation of junk candies, breakfast cereals, snack foods, and other processed concoctions, it’s no surprise that companies are using more synthetic dyes.

But it may surprise consumers to learn that, although all food colourings must be approved by Health Canada, there are lingering questions about the safety of most of the 10 synthetic dyes that can be used in food (allura red, amaranth, brilliant blue, citrus red No. 2, erythrosine, fast green, indigotine, Ponceau SX, sunset yellow, and tartrazine). Here are four examples.

• Erythrosine. The dye, which is also known as Red 3, was banned from cosmetics and topically applied drugs in the United States 20 years ago because it caused thyroid cancer in animals.

In 1984, the then-acting U.S. Food and Drug Administration (FDA) commissioner declared that erythrosine was “of greatest public health concern” and “has clearly been shown to induce cancer.” But the FDA never got around to prohibiting most uses in food. Neither has Health Canada.

Erythrosine is used in foods like imitation bacon bits and some kinds of ice cream, dessert sprinkles, and frozen pops. The dye is sometimes also used to colour pistachio shells.

• Allura red. The dye, which is also known as Red 40, seemed to speed up the appearance of immune system tumours in one mouse study, but not in a second study. The inconsistency—and therefore the safety of allura red—was never satisfactorily resolved.

Allura red is used in foods like fruit punch, biscuits, tomato juice cocktails, tomato-flavoured crackers, cake mixes, and imitation bacon bits.

• Tartrazine. The dye, which is also known as Yellow 5, causes sometimes-severe hyper sensitivity reactions, mainly hives, in some people. (Allura red and sunset yellow also have caused allergic-like reactions.)

Because of the possibility of allergic reactions, some food companies voluntarily list tartrazine by name on their labels.

Hives isn’t the only concern with tartrazine. In six of 11 test-tube or animal experiments, the dye damaged DNA. That’s often a sign that a compound is a carcinogen.

But tartrazine didn’t cause cancer in the only good rat study. Still, health authorities typically require tests in at least two rodent species, and a study in mice didn’t meet standard research guidelines.

Another reason to worry about tartrazine: it can be contaminated with the human carcinogen benzidine. So can sunset yellow.

Bottom line: until more studies are done, tartrazine shouldn’t be allowed in food.

Tartrazine makes foods lemon-coloured, so it often shows up in lemonade and lemon cake. It also mimics the colour of cheese, so it’s a regular in foods like mac and cheese, dehydrated au gratin potatoes, and crunchy cheese snacks. And it’s what gives most pickles their pickley colour.

• Amaranth. The dye, which is also known as Red 2, was banned in the United States more than 30 years ago because it caused cancer in female rats. Amaranth ranges from reddish-brown to dark red to purple, and it can be used to dye ice cream, gravies, soft drinks, cake mixes, and puddings.

ADHD in Children
For 40 years, parents and pediatricians have complained that foods made with synthetic colours worsen the behaviour of some children. And for 40 years, the food industry and government regulators have dismissed the claims as unproven.

But when a 2004 meta-analysis pooled the results of 15 studies, it found a “modest” worsening of behaviour in children diagnosed with attention deficit hyperactivity disorder (ADHD) who were given foods with synthetic dyes.[1]

Since then, two large studies commissioned by the British government showed that dyes can also affect children who haven’t been diagnosed with a behavioural disorder.

In one, University of Southampton researchers gave beverages with and without six dyes to 137 three-year-olds and 130 eight- and nine-year-olds who had been recruited from local nurseries and schools. The amount of dye in the drinks was equivalent to what’s found in four to eight ounces of candy.

The children’s inattention, impulsivity, and overactivity—as measured by a composite score from teachers, parents, the researchers, and a computerized test— increased slightly but significantly after the youngsters drank the colours-laced drink compared to another occasion when they drank a similar-looking but colours-free placebo.[2]

The teachers, parents, and researchers didn’t know which drink the children had consumed when they did their rating.

In response to these studies, the British government urged the food and restaurant industries to remove the six dyes by December 31, 2009. (Three of the six— allura red, tartrazine, and sunset yellow— can be used in food in Canada.)

What’s more, the European Parliament passed a law requiring a warning notice (“may have an adverse effect on activity and attention in children”) on foods that contain at least one of the six dyes.

Those actions prompted the Canadian government to act.

Health Canada scientists who reviewed the UK and other studies agreed that there was credible evidence of behavioural changes in children who consumed certain synthetic food colours.

But instead of banning the dyes or requiring a warning notice, the agency announced last February that it simply plans to require food companies to label their products with the specific names of any synthetic food colours they use.

While the agency mulls over comments on its proposal by the food industry and consumer groups, “in the interim, Health Canada is encouraging those food manufacturers who do not already do so, to voluntarily declare food colours by their individual common names,” said spokesperson Joey Rathwell.

“Health Canada’s goal is to enable consumers to make more informed choices which could contribute to the reduction of adverse reactions.”

The Bottom Line

Synthetic dyes have caused allergic-type reactions in some people and hyperactive behaviour in some children, have caused cancer or mutations in some animal studies, and/or haven’t been adequately tested. What’s more, they have no nutritional benefit and are often used in junky kids foods or other foods of little value.

Our advice: Consumers should try to avoid dyes when they can, the food industry should switch to safe, natural colourings, and Health Canada should ban the dyes.

Sources:
1 J. Dev. Behav. Pediatr. 25: 423, 2004.
2 Lancet 370: 1560, 2007.

Michael F. Jacobson is executive director of the Centre for Science in the Public Interest (CSPI), the nonprofit publisher of Nutrition Action Healthletter. Sarah Kobylewski is a Ph.D. candidate in the molecular toxicology program at the University of California, Los Angeles.

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