Synthetic food dyes are used in many processed foods, such as colored breakfast cereals, candy, and “fruit-flavored” beverages and snacks. A total of 15 million pounds of dyes are added to the U.S. food supply each year. Our consumption of food dyes has increased 5-fold since 1955 as our nation has consumed more and more packaged foods.1
These synthetic dyes have been linked to a wide variety of health concerns including behavioral problems, hyperactivity, allergic reactions, and even cancers. The Center for Science in the Public Interest (CSPI), an organization that advocates for nutrition and food safety, called for a ban on these synthetic dyes. Food-based dyes such as beet juice and turmeric are readily available, but are more expensive and often less bright, making synthetic dyes more attractive to food manufacturers.
Food dyes and allergic reactions:
Blue 1, Red 40, Yellow 5, and Yellow 6 have been reported to cause allergic reactions in some people.
Food dyes and hyperactivity:
Food dyes are of particular concern for children, since many colored foods are marketed to children, and their smaller body size makes them more susceptible to potential toxins. Hyperactivity in children following ingestion of food dyes is well-documented in placebo-controlled studies. Furthermore, a 2004 meta-analysis of 16 studies in children who were already hyperactive showed that their hyperactive behavior increased in response to food colorings.2 In a study published in Lancet in 2007, researchers tested two different mixtures of food dyes vs. placebo in children of two age groups – one mixture increased hyperactivity in 3 year old children, and both mixtures increased hyperactivity in the 8-9 year-olds.3 This study sparked a reaction by the British government. They instructed food manufacturers to eliminate all of these synthetic dyes by the end of 2009. In fact, a warning notice is now required on dyed foods in Europe stating that these foods “may have an adverse effect on activity and attention in children.”4 As a result, several international food companies now produce products with food-based dyes or no dyes in the U.K., but continue to include synthetic dyes in their U.S. products.
Food dyes and cancer:
There are eight commonly used synthetic dyes in the U.S., and all have undergone toxicity and tumorigenicity testing in animals. CSPI summarized the results of cancer-related studies in a report1:
- Red 3 was acknowledged by the FDA to be a carcinogen in 1985 and was banned in cosmetics and externally applied drugs. However Red 3 is still used in ingested drugs and foods.
- The three most widely used dyes (Red 40, Yellow 5, Yellow 6) which account for 90% of dyes in the U.S. are contaminated with low levels of chemical carcinogens, as byproducts of the manufacturing process. Although the FDA places limits on the concentrations of these contaminants in the final dye products, they still may pose risks.
- Citrus Red 2 added to the diet resulted in bladder tumors.
- Red 3 resulted in thyroid tumors and caused DNA damage.
In their report, CSPI noted flaws in many of the animal cancer studies on Yellow 6, Yellow 5, Red 40, Green 3, and Blue 2, including bias – most studies were either commissioned or conducted by dye manufacturers, short duration, and lack of exposure to dyes during fetal development. Additional studies are likely needed to determine whether these dyes are safe.
The simplest and most effective way to avoid the potential harmful effects of synthetic dyes is to avoid processed foods. Unrefined plant foods contain health promoting phytochemicals, not empty calories and synthetic additives of questionable safety. When buying the occasional packaged food, check the ingredient list to avoid synthetic dyes.
1. Center for Science in the Public Interest. Food Dyes: A Rainbow of Risks. http://cspinet.org/new/pdf/food-dyes-rainbow-of-risks.pdf
2. Artificial food colouring and hyperactivity symptoms in children. Prescrire Int. 2009 Oct;18(103):215.
Schab DW, Trinh NH. Do artificial food colors promote hyperactivity in children with hyperactive syndromes? A meta-analysis of double-blind placebo-controlled trials. J Dev Behav Pediatr. 2004 Dec;25(6):423-34.
3. McCann D, Barrett A, Cooper A, et al. Food additives and hyperactive behaviour in 3-year-old and 8/9-year-old children in the community: a randomised, double-blinded, placebo-controlled trial. Lancet. 2007 Nov 3;370(9598):1560-7.
4. CSPI Says Food Dyes Pose Rainbow of Risks. http://cspinet.org/new/201006291.html