Is it true that white ppl don't live as long as black ppl in the tropics without the help of modern medicine?

in a "native" world yes, this would be true. This is because darker skin tones help protect against the sun's rays to an extent reducing the risk of skin cancer. And often times, races that are from the tropics are more naturally resilient to vertain diseases such malaria. However, in a modern society, there would be relatively no difference in life expectancy.