The challenge you have here is that aspartame isn't just one of most widely studied substances in the food chain, but that it's also one of the most widely and vigorously consumed. People drink a lot of diet soda; a lot of people drink it to the exclusion of all other liquids. So it's going to be tricky to get the epidemiology to match up with the claim here: if aspartame is meaningfully carcinogenic (meaning: more t…
n=102,865 adults were followed for a median 7.8 years, using 24-hour dietary records collected via web including some photographic validation. Key results:
> In particular, higher cancer risks were observed for aspartame (HR = *1.15* [95% CI 1.03 to 1.28], P = 0.002) and acesulfame-K (HR = *1.13* [95% CI 1.01 to 1.26], P = 0.007).
+13~15% raised cancer risk in high consumers of aspartame and acesulfame-K (controlling for many factors, including sugar intake, BMI and weight gain, physical activity, etc.).
> In particular, no difference was detected between the categories ‘higher artificial sweetener consumption and sugar intake below the official recommended limit’ and ‘no artificial sweetener consumption and sugar intake exceeding the recommended limit’
So the raised cancer risk was statistically the same for both categories (though possibly slightly worse for artificial sweeteners). No real win for sugar there (but we also have to look at their performances in the area of CVD and diabetes).
(I will say that the 100g/day cutoff for high vs low sugar consumption is kind of high, even if it includes sugars in fruit and other whole foods. The key question imo is: how would low sugar + low sweetener consumption fare against the equivalent amount of sugar?)
Overall, definitely an interesting study, considering that they adjusted for a lot of factors including BMI/weight gain, and that it's the more health-conscious types who would consume artificial sweeteners. Even the lower-consumption category was associated with a statistically significant +14% raised cancer risk vs non-consumers (for the same level of sugar intake).
One point to note was that sucralose intake didn't seem associated with raised cancer risk, the caveat being that the sucralose sample size was about half those of aspartame and acesulfame-K. This could possibly reflect sucralose being a sweetener used by the most health-conscious participants, since it's less commonly used in mass-market products. Still, would be interesting if sucralose might not contribute to cancer risk. Overall, this paper is a non-loss for sucralose on the cancer front.