April 4, 2006 (Washington) -- Diet soda lovers may be able to sip a little easier, thanks to a new study that shows that the artificial sweetener aspartame does not raise the risk of cancer.
But the new study -- conducted in people, not rats -- found no such link. Nor did the popular sugar substitute raise the risk of brain cancer, says researcher Unhee Lim, PhD, of the National Cancer Institute.
The findings were presented at the annual meeting of the American Association for Cancer Research here.
No Link to Cancer
Lim and colleagues studied 473,984 men and women, aged 50 to 71, participating in the National Institutes of Health-AARP Diet and Health Study.
In 1995 and 1996, participants were asked how much they drank of three popular diet beverages -- soda, fruit drinks, and iced tea. They were also asked if they added aspartame to their coffee and tea.
From their answers, the researchers calculated how much aspartame they consumed on a daily basis.
During the next five years, 1,972 of them developed lymphoma or leukemia, and 364 developed brain tumors.
When the researchers looked at people who consumed an average of at least 400 milligrams of aspartame a day -- about the amount found in two cans of soda -- there was no link between aspartame consumption and any of these cancers.
Findings Somewhat Reassuring
Michael Jacobson, head of the consumer watchdog group Center for Science in the Public Interest, says the findings are somewhat reassuring.
Jacobson, who had pushed for a government review of aspartame's safety after the rat study was published, says, "The new study is in humans and goes a long way toward alleviating many concerns."
That said, the study design was subject to so-called recall bias, as participants were asked to remember what they drank and how much they drank, he says.
"If their recollections weren't accurate, it compromises the findings," Jacobson tells WebMD.
Lim acknowledges the point. She says that is one reason why she is not ready to make any public health recommendations about aspartame consumption at this time.
"This is a first step," she tells WebMD. "We need to verify the findings and also study possible links between the sweetener and other cancers as well."