[pvaldes]

> Why do they fear this?

Modern medicine had seen before severe cardiovascular accidents and is aware of what a damage in young arteries or heart can produce. Some tissues can self-repair better than other.

The origin is new, but the consequences of damage on any main organ are well studied.

[Vysero]

Right, but first we have to establish that they actual fear this. Then we have to establish who they are, and what their qualifications are. Then, as non-experts, if enough experts agree with the ones who are making the claim we can choose to worry or not to worry depending on circumstances.