While genetics might play a small role for very specific reasons (eg a society thats prone to sickle cell disease will likely live shorter), there’s no such difference in large, diversified populations like US/Europe.
And most of the US gets a lot more sun exposure than most of europe. Also African americans...Well just black people in this context are more than twice as likely to get prostate cancer (more like 3 times given lower detection i've heard it said) supposedly because they have higher testosterone.
Not many ancestrally native Americans in Europe, relatively few jews compared to the USA (but more other semetic groups, I don't know if that balances or not), the sub-saharan Africans in Europe had a lot more volunteers and less industrialised human trafficing and are in any case very much more diverse genetically than people think due to superficial characteristics like skin colour (seriously, substitute race discussion about skin to be about blonde vs brunette to see how silly the groups are), and there's more of Irish in the US than the current population of Ireland.