Or you could just... you know... live your life and train. Outliers are not determinant of your outcome. I would rather achieve a black belt then sit in my room for the rest of my life because everything outside is dangerous.
Obviously that's an extreme dichotomy. I have a plethora of hobbies that are relatively dangerous, but all in context.
Obviously I think from my perspective, the data is not comprehensive which screws with my brain.
For everyone on here to read.... some extra data below from my gym
Anecdotally, I had briefly heard of this before and not payed a ton of attention to it because honestly you can get fucked up from doing anything, so I wasn't surprised to see some BJJ guys having problems with strokes and I figured they probably had pre-existing conditions. For example, I know a lot of divers, but I knew one guy personally who went on a dive for the first time and died due to a condition in his lungs he didn't know he had. Sucks, but it's not statistically significant and you can get killed doing anything, especially if you don't know you have a pre-existing condition.
That said, a few months ago, a guy at our gym who is a blue belt had a stroke a few hours after training. The worst part is it was a fundamentals class with no live-roll. These classes are frequented by new trainees but older, experienced guys supplement them as well as they become an attention-to- detail presentation and are excellent for drilling/active recovery. If your body is banged up, but you don't want to sit at home and rest, you do a fundamentals class. That's how they are presented. All instruction, all drilling, no live roll.
They had drilled some type of lapel choke, and he claims the guy who did it to him did it too aggressively more than once, but nothing that made him concerned. A few hours later, he has a stroke at home. He is going to be ok, and will likely train again, but it's a longish recovery (doc says 6 months to a year).
Note: My instructor competes at worlds and is well known in the jiu-jitsu community. He had not heard of this possibility before at least he says. He called the other gyms under our same banner to report what had happened and get advice, and they ALL had instances of this already. It has changed the atmosphere of the gym a bit in that I've noticed they are very careful about new people rolling (handpicking your partners for months, whereas before it was like anyone can roll with anyone). That said, that's not super comforting because this happened during drilling and it happened with a guy who has been training for years and is a strong individual with a thick ass neck so I hate that I can't make sense of it.
I wish we had more data on this...