A rigorous study of 100 people, using hard tests, as as good of a gold standard you can get. The studies "proving" that high LDL causes heart disease are not rigorous.

Also - very important point here - this study was not funded by big pharma or government (sometimes one and the same)!

Instead, it was self-funded, by a guy who went on a keto diet, felt really great afterwards but was told by his doctor that he'd die because his LDL cholesterol was so high, and decided to investigate.

Here's the group that did it - https://citizensciencefoundation.org/.