Controversial from DAY 1. I remember front page WSJ article stating that FDA approved this in record time and the FDA commission who approved it, then worked for the marketing company handling Aspartame.
http://h2rc2.com/Ecogypt/page1/page17/assets/AspartameResearch.pdf
Aspartame is the most controversial food additive in history
https://www.arizonaadvancedmedicine.com/articles/2013/june/aspartame-history-of-getting-fda-approval/#:~:text=On%20July%2018%2C%201981%20aspartame%20was%20approved%20for,should%20not%20be%20approved%20if%20tests%20are%20inconclusive.
"Aspartame has been controversial since day one. Searle, the manufacturer, had failed to win FDA approval for 16 years and was under investigation for performing fraudulent studies. Aspartame was suddenly approved in 1981 when Donald Rumsfeld, former CEO of Searle and new member of President Ronald Reagan's transition team, appointed a new FDA commissioner."