Thanks for your reply and the references, I'm still working through them.

I'm not diabetic but where possible I avoid drinks high in sucrose and especially fructose for all the obvious reasons, so often the only choice available are those with artificial sweeteners.

However I'm concerned about my consumption of artificial sweeteners and try to avoid them where it's practical to do so. What's annoying are the many reports and studies about artificial sweeteners that imply that they have negative impacts on health but essentially none come to an outright conclusion that they are actually harmful and should be banned. When it comes to artificial sweeteners, we live in a do-nothing world.

For example, look at the hundreds of papers and reports about aspartame and still there are heated arguments over its safety the majority of which reckon it's safe. Despite the long history of reports about aspartame being safe it was nevertheless declared a possible carcinogen in 2023 by the International Agency for Research on Cancer (IARC); this being some 50 years after its introduction! With multiple studies, five decades of use and millions of consumers surely by now we ought to know one way or other whether aspartame is a carcinogen or not. How the hell is the average consumer to make sense of this new conflicting information?

Like most consumers I'm not a biochemist so I've not enough knowledge to do a proper risk assessment on aspartame or any other artificial sweetener, so how are we users to decide what's best and what to do?

For my part I use my somewhat limited knowledge of organic chemistry to decide which sweetener to consume. Despite the IARC's statement that aspartame may be a possible carcinogen I'd risk using it over say Sucralose. My rationale goes like this: aspartame is an ester dipeptide of aspartic acid and phenylalanine which are essential amino acids the body uses in protein synthesis and we understand that process. Moreover, we understand how aspartame is metabolized/breaks down and that the byproducts are mostly harmless but not all are—a nasty one being methanol. Whilst methanol is certainly dangerous the amount produced by the normal consumption of aspartame is less than the amount of methanol the body produces naturally (yes, the body does produce small amounts of methanol and knows how to handle it).

Compare that with Sucralose/E955 which is produced by the chlorination of sucrose where three of its hydroxyl (OH) groups are replaced by chlorine atoms. It seems that unlike sucrose most sucralose is not broken broken down by the body which means that part passes through the body without doing it harm. What remains unclear to me is what happens with the small amount of sucralose that the body does break down. What exactly happens to those three chlorine atoms during the molecule's reduction? There are reports about the dangers of sucralose but it remains unclear what they are and what exactly are its metabolites. (With aspartame, at least we know its produced from amino acids that the body is used to handling, but I'd agree that's not a solid argument.)

I'm not suggesting my rationale is right, nor do I suggest anyone follow it. What I am saying is that even those of us who have some knowledge of organic chemistry cannot get to the bottom of this sweetener problem. Why after 50 or more years has this matter not been resolved? If artificial sweeteners are a major concern then you'd reckon after such a length of time and with millions of users there'd be statistically significant numbers of medical incidents but that seems not to be the case.

Until matters are finally settled what are users of sweeteners supposed to do?