I've actually no scientific proof of course that this actually even happens? But I've always been under the impression that when anyone is born you get like a genetic playing card if you will.
Most of us if lucky get a 7 or 8 the unlucky ones a 2 or 3 & the very lucky ones a king or an Ace, only musings of course, but when someone like my old mum who would eat sensibly, never drank (not even a glass of wine at Xmas dinner)& never smoked died at 60 from cancer & yet you see people like Shane MacGowan & Keith Richards still up & at it albeit at maybe a slower pace, it does make you wonder.

Pro USA & Israel

There's something to this yes. On average it makes sense that living to excess (smoking, too much alcohol etc) does often eventually have an impact, but there will always be those who do it all right and end up with the sh!t end of the stick, and vice versa. All ywe can do is your best to maxamise health in a sensible rather than excessive way, and hope for the best.

I take the point about microplastics and the like too. We never know what the impact of this stuff, and chemicals in food and the like is long term, but other than doing our best to avoid pitfalls, it's all a bit of a routine spin. Some get lucky, some the opposite.