The pilot study launched by the Food Standards Agency (FSA) into the health effects of individuals “self-reporting as sensitive” to aspartame has been criticised for being an unnecessary waste of precious research resources.
A spokeswoman for aspartame supplier Ajinomoto argued that the safety of aspartame had been proven time and again in various robust studies over the years. Consequently, she said, there was no scientific justification for the FSA embarking on the latest pilot. Her comments followed a meeting last week of the FSA’s General Advisory Committee on Science (GACS).
She also argued that the number of people reporting adverse side effects following consumption of aspartame was so small that money would be better spent counselling these people individually.
Some members of the GACS committee also expressed concerns about the study. Jeya Henry, professor of human nutrition at Oxford Brookes University, questioned the scientific approach of the pilot study, in particular the use of high numbers of volunteers with self-diagnosed sensitivity issues.
“I really think the sensitivity issue may need to be rethought because the model that you are using is going to be loaded against you proving what you want to prove,” said Henry. His concerns about using people who were “self-reporting” were echoed by Dr Ian Brown, chair of the Advisory Committee on Animal Feedstuffs.
However, professor sir Roger Jowell, chair of the FSA’s Social Sciences Research Committee, added: “My worry was the description of the study - to investigate anecdotal claims - it is actually more than that and of course it is less than a randomised control trial. I think it is important to describe it as a limited controlled trial. But what you are doing is effectively putting your toe in the water, and as a first stage that is perfectly acceptable.”
Even if the study gave a green light to aspartame, this might make little difference to people who were convinced that it did adversely affect them, said GACS chairman, professor Colin Blakemore.
However, he noted that: “The fact is that somatization [a psychological condition in which some people persistently complain of varied physical symptoms that have no identifiable physical origin] is a very real phenomenon.”
“Aspartame is a controversial issue,” admitted FSA chief scientist Andrew Wadge. “And, indeed, the idea of doing a study like this is controversial. Whenever there is a scientific evaluation on safety, the answer comes back that this product is safe to consume … and yet we have the situation where a significant number of people who are convinced that they react to this particularly product.”
The FSA’s latest pilot aims to recruit 50 individuals “self-diagnosed” as sensitive to aspartame and 50 age/sex matched controls, who are normal, healthy volunteers. Volunteers will be asked to consume a product which may or may not contain aspartame and any resulting health effects will be recorded.
According to Wadge the study aims to investigate anecdotal claims made by individuals and test the suitability of a food product developed by the FSA for use in ‘blinded’ trials. “I personally think it is something that is interesting and worthwhile doing,” said Wadge.
The pilot study will inform the design and feasibility of a larger-scale study that could be done at European level, he added.
The European Food Safety Authority (EFSA) recently provided a clean bill of health to aspartame. However, it is reported to be undertaking a further review of published reports and “some anecdotal reports” since the Scientific Committee on Foods issued an opinion on aspartame in 2002.