Don’t do it, Ezra. You just calmly finish drinking that diet soda and don’t concern yourself for one second. I know you’re worried, because you fearfully tweeted earlier today about this Tom Philpott story at Grist about how diet soda causes cancer.  But the best thing you can do for your health is not listen to Tom Philpott, because the unnecessary stress caused by worrying about the aspartame in your diet soda is far more dangerous for you than the aspartame in your soda. Philpott brings two pieces of evidence to bear in his argument that diet soda is bad, neither of them will be unfamiliar to you if you’ve followed the debate (I use the term “debate” loosely, in the same sense that we’re “debating” whether 9/11 was an inside job). The first is the old story hippies tell each other around the campfire about how Donald Rumsfeld and Reagan-fueled ’80s snuck aspartame past the FDA with all sort of hijinks. Not only is this story old, so too is it’s debunking. The GAO was asked in 1987 to do a full retrospective study of the approval of aspartame by the FDA and here is what they reported:

FDA adequately followed its food additive approval process in approving aspartame for marketing by reviewing all of Searle’s aspartame studies, holding a public board of inquiry to discuss safety issues surrounding aspartame’s approval, and forming a panel to advise the Commissioner on those issues. Furthermore, when questions were raised about the Searle studies, FDA had an outside group of pathologists review crucial aspartame studies.

The second piece of evidence is a study by the Ramazzini Foundation, whose name also familiar to anyone following the aspartame “debate”. Here is what the FDA had to say about this study in September of 2010:

FDA could not conduct a complete and definitive review of the study because ERF did not provide the full study data. Based on the available data, however, we have identified significant shortcomings in the design, conduct, reporting, and interpretation of this study. FDA finds that the reliability and interpretation of the study outcome is compromised by these shortcomings and uncontrolled variables, such as the presence of infection in the test animals.

Additionally, the data that were provided to FDA do not appear to support the aspartame-related findings reported by ERF. Based on our review, pathological changes were incidental and appeared spontaneously in the study animals, and none of the histopathological changes reported appear to be related to treatment with aspartame.

The FDA aren’t alone in believing aspartame doesn’t cause cancer. They’re joined in this conclusion by The American Cancer Society, National Cancer Institute, National Institutes of Health, and the Mayo Clinic. So you can trust Tom Philpott and the Ramazzini Foundation or you can trust the most highly esteemed medical institutions in the United States. Like I said Ezra, drink up.

If you want even more details about this tall tale (let’s face it, you don’t), here is an older post where I dig in much more.