We keep encountering situations like this where a new chemical compound was introduced, becomes ubiquitous in our diets or environments and only later do we find out "Oops, it has serious health or environmental consequences."
It is worth the cost of slower introduction of new materials to take the time to ensure that those materials are safe. We're still paying the cost of introducing lead into our environment in a myriad of subtle ways. We still don't fully understand what the cost of the introduction of microplastics or PFAS is going to be. And regardless of the whether this particular study holds up under replication it is looking increasingly likely that aspartame is not something we should be consuming.
And what's most frustrating is that the people who profited most from these compounds never pay for the damage they cause to generations.
What specific studies should we have done to notice this association? What specific safety studies need to be done before introducing a new chemical compound into our society?
Historically speaking, the only conceivable way they would have learned this if they feed aspartame to pregnant women and then studied the offsprings. This is fine for a final testing phase of safety, but is inhumane to do unless you are incredibly sure it is safe. Animal models for studying autism are flawed, and wouldn't come at all for decades after aspartame's introduction.
In modern testing, we could theoretically generate a super long list of safety checks to do. This test might look like raising a large generation or two of the specific line of mice used for studying autism. Then checking the offspring autism rate of those exposed to aspartame compared to a control. This would be a single checkbox every new chemical compound would need to do, and there could easily be tens of thousands of similar tests that would need to be done. We would need to add to the list overtime, as our understanding of optimal human health improves over time.
Imagine the investment required to pass these safety tests. It's a minimum price tag of 25M, if the safety tests are standardized and lab techs are trained on them and do them in an assembly line like fashion. I wouldn't be surprised to see the cost be 10-100x. At that level of investment there's two issues. The number of new chemical compounds added into our lives will move to a very slow rate. The other problem is this is just the safety test portion of R&D, after spending so much money this seems like a likely target for corruption and my skepticism for the results of such a test will be high.
The bad stuff we may already be eating is a given, and something to be distinguished from introducing new things with no existing role in the foot chain.