Scientists are to assess whether the artificial sweetener aspartame causes health problems in people unusually sensitive to it.

科学家正在评估人工甜味剂阿斯巴特是否会引起对此异常敏感的人的健康问题。

Aspartame is widely used in many food products

Expert advice is that aspartame（阿斯巴特） - found in more than 4,000 products - is safe to consume.

However, a number of people have reported sensitivity to the product including headaches, dizziness, vomiting¹, diarrhoea（腹泻） and fatigue（疲乏，疲劳）.

The University of Hull² study is funded by the Food Standards Agency (FSA).

Aspartame, 150 times sweeter than sugar, is found in products such as diet soft drinks, cereal（谷类食物） bars（马齿龈）, yogurts（酸牛奶） and chewing gum.

There have long been concerns that the sweetener is linked to a raft of（许多） health problems, including a greater risk of cancer, fertility issues, nausea³, double vision and an effect on appetite.

However, after reviewing the available scientific literature, both the FSA and the European Food Safety Authority decided⁴ there was no firm evidence of any impact on health, and ruled that aspartame was safe to consume.

Professor Stephen Atkin, who will lead the new research, said: "This study is not to determine whether aspartame can be consumed safely; this has already been established, but rather to see whether certain people are sensitive to it."

The Hull team hope their work will lead to a larger international study to pin down（迫使履行） the issue once and for all（彻底地）.

Body chemistry

Professor Atkin also hopes to secure funding to analyse the chemical breakdown⁵ of aspartame in the body.

The sweetener can be broken down to produce methanol（甲醇） and formaldehyde（甲醛）, both of which have been previously⁶ linked to cancer.

However, it is not clear whether this process takes place in the body, or, if it does, whether the metabolites（代谢物） are absorbed into the blood in sufficient quantity to produce any biological effect.

Andrew Wadge, Chief Scientist at the Food Standards Agency said: "The study will address consumer concerns, including anecdotal（逸话的，轶事的） reports that have linked a range of conditions to aspartame.

'The Agency's view remains⁷ that aspartame can be consumed safely and we are not recommending any changes to its current use.

"However, we know that some people consider that they react badly to consuming this sweetener so we think it is important to increase our knowledge about what is happening."

One hundred people will take part in the Hull study, half of who have complained of side effects from aspartame.

The study is expected to take 18 months.

At present the Acceptable Daily Intake⁸ (ADI) for aspartame is set by the European Commission's Scientific Committee on Food (SCF) at 40 milligrams per kilogram of body weight.

An adult would have to drink about 14 cans a day of diet soft drink, or consume about 80 sachets（小袋） of sweetener to reach this amount.