The study, conducted at Cardiff University in the UK and published in the October issue of the British Journal of Psychiatry was based on data from 17500 participants in the 1970 British Cohort Study.
The researchers found that 69 per cent of the participants who were violent at the age of 34 had eaten sweets and chocolate nearly every day in childhood. In contrast, 42 per cent of those who were non-violent at 34 had eaten sweets with the same frequency.
The observation was found to hold true even after other factors were taken into consideration, such as the behaviour of their parents, educational qualifications, and where they lived.
The study’s publication will cause consternation amongst parents since confectionery’s effect on behaviour has been much in the news recently. The so-called Southampton study, published in The Lancet in 2007, saw a link between certain cocktails of food colourings and hyperactivity in children.
Although the colouring mixtures were made by scientists and not food product formulators, and European Food Safety Authority found it did not give grounds to alter the acceptable daily intake levels of any of the additives used, it has led to pressure for confectionery makers to use natural colours in their bright products.
The Cardiff researchers, led by Dr Simon Moore, proposed a number of explanations to the sweet-eating–violence observation. They toy with the idea that confectionery could make the adult addicted to certain additives, and that these could underlie the aggression.
However their “favoured” explanation was not linked to the ingredients of the confectionery per se. Rather, they propose that children who eat sweets regularly “may not learn how to wait to obtain something they want”.
“Not being able to defer gratification may push them towards more impulsive behaviour, which is strongly associated with delinquency,” said Moore.
Some in the food industry are unconvinced by the connection.
Julian Hunt, director of communications at the Food and Drink Federation, said: “This is either utter nonsense or a very bad April Fool’s Day joke! Anti-social behaviour stems from deep-rooted social and environmental factors, such as poor parenting and a deprived upbringing, and is not linked to whether or not you ate sweeties as a kid.
“How anyone could leap to such a conclusion is beyond me.”
David Zimmer of the chocolate, biscuit and confectionery trade association CAOBISCO, had not yet had the opportunity to see the methodology underpinning the ‘findings’, but expressed concern at the “sensationalist and ill-defined commentary already hitting the media wires”.
“This is not helpful to consumers who need good advice based on sound science. Looking at the media statements by the researchers they appear to have taken a causal leap in the dark to satisfy preconceived notion,” he said.
“As a serious industry we recommend our consumers to eat confectionery in moderation as just one small part of a balanced, healthy diet. Nutrition experts continue to confirm also that confectionery plays an exceedingly minor contributory role to the overall diet, contrary to the implications behind this story.
“It is of concern that a serious issue such as anti-social behaviour, which has many complex roots, should be allowed to be trivialised.”
More work needed
The researchers concluded that more work is needed on the association between confectionery consumption and violence, and it may prove beneficial to channel resources towards improving children’s diets.
Although this study purports to be the first to look at the long-term effects of childhood diet on adult violence, some interesting studies on omega-3, most commonly found in fish, could indicate a link between nutritional deficiencies and aggressive behaviour.
A 2002 study gave essential fatty acid supplements to 18-21-year-old prisoners and found antisocial behaviour was reduced by 37 per cent compared to placebo. A new, larger scale study in three UK prisons was initiated in 2008.