Food dye and ADHD

For more than 30 years, scientists have examined the relationship between food colouring and hyperactive behaviour in children, but with mixed results. To date, no conclusive evidence has been found to show that food colouring causes ADHD. Some studies, though, have suggested an association between the two. Most likely, ADHD is caused by the combination of changes in brain structure, environmental factors, and heredity.

Can food dye cause hyperactivity?

A study by the Food Standards Agency in 2007 showed that the consumption of foods containing certain dyes could increase hyperactive behaviour in children. In the study of three to eight and nine-year-olds, children were given three different types of beverages to drink. Then their behaviour was evaluated by teachers and parents.

One of the drink mixtures contained artificial food colourings, including:

• Sunset yellow (E110)
• Carmoisine (E122)
• Tartrazine (E102)
• Ponceau 4R (E124)

It also contained the preservative sodium benzoate. The second drink mixture included:

• Quinoline yellow (E104)
• Allura red (E129)
• Sunset yellow
• Carmoisine

It also had sodium benzoate. The third drink mixture was a placebo and contained no additives.

The researchers found that hyperactive behaviour by the eight and nine- year-olds increased with both the mixtures containing artificial colouring additives. The hyperactive behaviours of three-year-olds increased with the first beverage but not necessarily with the second. They concluded that the results show an adverse effect on behaviour after consumption of the food dyes.

What is in food dye?

Food colouring consists of chemicals used to add colour to food. Food colouring (dye) is often added to processed foods, drinks, and condiments. They are used to maintain or improve the appearance of the food.

Manufacturers usually add dye for the following reasons:

• To add colour to colourless foods
• To enhance colours
• To avoid colour loss due to environmental elements
• To provide consistency when there are variations in the colouring of the food

The FSA regulates colour additives to ensure that they are safe for human consumption. Regulation also helps ensure that foods with colouring are accurately labelled so that consumers know what they are eating. To determine the approval of an additive, the FSA studies the composition of it and how much is consumed and notes any health effects and safety factors that need to be observed. Once the food dye is approved, the FSA determines an appropriate level of use for that additive. The FSA only allows an additive to be approved if there is a reasonable certainty of no harm to consumers.

There are two types of approved colour additives, dyes and lakes. Dyes are water-soluble and usually come in the form of powders, granules, or liquids. Lakes are not water-soluble. They are found in products containing fats and oils.

Some food colourings are synthetically produced. Other food colourings come from pigments of vegetables, minerals, or animals. Examples of these natural additives include beta-carotene, grape skin extract, caramel colour, and saffron.