Artificial sweetener aspartame is not linked to cancer, claims a study published in the Annals of Oncology.
Researchers compared levels of sweetener consumption by cancer patients with those of a control group of patients without cancer over a 13-year period. They found no correlation with cancer rates.
There have been concerns about the possible carcinogenic effects of aspartame since the 1970s, though the FSA says it is safe.
But Liberal Democrat MP Roger Williams, who is campaigning for aspartame to be banned, said: "This study is just one in the face of several that point to an increased rate of cancer incidences."