Well back in the slave days the whites did selectively breed the best genetics with the best genetics. It’s a shitty way of life... But these days especially in the south you see more obese African Americans than whites...
But beside the point, Dre has obviously worked hard to look as good as he does at his age no matter what. Also, a lot of celebrities have (like Dre) have the funds to supply themselves with the best of the best cutting edge drugs. With him being in Cali, there are tons of HGH and hormone replacement clinics available for him. And legit, he is of age to start getting all of these things legally.