Newcomer question - Adding milk to coffee

[Estivela]

Hi there!!

I am new in the forum, even though I've been drinking coffee for years. I would like to know if there are any studies that proof that the best way to taste properly coffee is through the addition of milk. I had a discussion with a friend of mine and he kept saying this. I am portuguese and love regular espresso coffee without any milk. And I prefer plain regular espresso with just coffee.
What you guys think or know??

Thanks in advance

Estive Lá