Contemporary processed foods contain many additives, largely to meet consumer expectations for great tasting products that are aesthetically pleasing, all year round. If we didn’t have all these expectations, many additives could be eliminated from our manufactured foods.
Any component added to food that doesn’t contribute to its nutritional profile can be described as a food additive. And in many cases, these additives allow us to improve the quality, safety and functionality of processed foods.
Take yogurt, for example: milk fermented under ideal conditions will not always form a thickened product, characteristic of what we know as yogurt. To ensure a consistently thickened product that meets customer expectations, pectin is added as a thickening agent, and consumers are happy.
So additives may form part of our everyday diets. But do they affect the behaviour of our kids or cause behavioural problems such as Attention Deficit Hyperactivity Disorder (ADHD)?
In two seemingly landmark studies published in 1975 and 1976, Dr Benjamin Feingold drew a link between food additives and behavioural disorders such as hyperkinesis or minimal brain dysfunction (the precursors to ADHD).
This research started decades of debate on the topic and led many parents to switch their kids to the Feingold diet, omitting foods with artificial colours, flavours and preservatives.
But immediately after those publications, various investigations in 1978, 1980 and 1981 refuted the link between childhood hyperactivity and food colouring. The authors concluded that even when administered at high levels, food additives, and particularly food colouring, did not alter kids' behaviour.
Now this is where it starts to get complicated. A 2007 Lancet study involving almost 300 children investigated the effects of six artificial colours and preservatives, known as the Southampton Six:
- tartrazine yellow (E102)
- quinolone yellow (E104)
- sunset yellow (E110)
- azorubine (E122)
- ponceau (E124)
- allura red (E129).
The researchers found the combination of additives increased hyperactivity in toddlers and school-aged children. But there was a key limitation to the study: the researchers were unable to determine the effects of any specific additive; just that one or more of the six additives (perhaps in specific combinations, or specific doses) had a negative affect on behaviour.
Most recently, a review summarising 35 years of research in this area concluded that artificial colours and flavours, including the Southhampton Six, did not cause ADHD. But in a particular subgroup of children with ADHD, a diet free from artificial food colours could improve their symptoms.
These groups of children are younger (more likely to be pre- or primary-school-age rather than in high school), have allergies or have irritability and sleep problems. Parents of children in these groups should therefore consider removing food additives from their child’s diet to test whether their symptoms can be alleviated. This can be attempted in parallel with, or as substitution to, drug-based therapy.
Finally, last year Food Standards Australia New Zealand (FSANZ) – the government regulatory body responsible for determining a product’s safety – concluded that the scientific evidence, including the Southampton study, did not demonstrate a link between consuming food additives and hyperactivity.
So what should we take from these studies and reviews? We still have much to learn about the effects of artificial colours and flavours, but so far, the research has found no causal relationship between food additives and behavioural disorders in children.