Do additives cause hyperactivity?
In 1975, a book called 'Why your child is hyperactive' was published by an American paediatrician called Dr. Feingold. He claimed that the behaviour of between 30% and 50% of hyperactive children improved dramatically if foods containing artificial colours, preservatives and flavourings, and foods containing naturally occurring salicylates, were removed from their diets. This sparked a controversy that still rages today.
Isle of Wight Study
In 2002, a report was produced by the Food Standards Agency that gave the results of an investigation into the effects of additives on the behaviour of a group of 3 year olds living in the Isle of Wight. It was widely reported in the media that it showed a link between hyperactivity and certain additives. However, the answers were not so clear.
|Results from Parents||Results from Psychlogists|
Parents were asked to rate their children's behaviour.
Additives had some effect on their children's behaviour.
Researchers put the children through psychological tests in controlled conditions.
Additives had no effect on the children's behaviour.
Who was right? The parents or the psychologists?
A follow-up study was started to try and find the answer.
Questions to ask of any test
There is a vast amount of information about food additives and hyperactivity on the internet. Much of it is unregulated and can be biased. Always look at the information closely to see how reliable it is.
- Is the number of people in any test large enough to give reliable results?
- Do the people being tested know if they are in the trial group or the control group? Good tests should be 'double-blind'. In this way neither the researchers nor the people in the trial know if they are being tested or are in the control group.
- Are the observations reliable and consistent? Is it personal opinions or scientific tests?
Measurements and tests need to be consistent throughout the whole group and not rely on personal judgments. For example, saying something is hot is very personal but stating that it is at 60°C is clear.
- Are the results analysed statistically to see if there are significant effects?