I keep getting "alt" wrong tue to false friend with latin languages (CA alt, ES/IT alto, LA altus...) where it means "high" (as in height), think of alto as high pitch.
Funny thing, apparently both meanings derive from same PIE root meaning "to grow", which of course can mean both "grow in age" and grow in height" ;-)
Of course, in Spanish "alto" has another meaning, halt, which comes from the German halt (hey, in English too!).
Judging by your ":)", I think you already know the answer.
The German sentence uses the neutral word Freunde, so the best translation into English is "friends".
It didn't use a more colloquial/informal/intimate word such as Kumpel and so using a word such has "buddies" is not as good a translation.
The English translations would be: "My friends are old," or "my female friends are old," alternatively, "My girlfriends/woman friends are old." are all precise translations as in English we do not distinguish what a friend or person's sex is. Thus, my initial answer "My friends are old" ought to be accepted as correct.