～ながら is sometimes translated as an adverb (e.g. 残念ながら = regrettably, unfortunately), but saying "ながら turns a noun into an adverb" is misleading. This ながら is close to while, although or despite. In English, while is particularly close to ながら in that it not only describes two actions happening simultaneously but it also expresses a contrast.
ながら can follow almost any noun, na-adjective and even i-adjective, but you should use it sparingly because it sounds fairly stiff or literary. Usually (だ)けど or (だ)が is preferred.
(literally: While that is regrettable, that is true.)
Regrettably, that is true.
(literally: Although this is rude, I will say ...)
I am afraid to say this, but ...
While it's a difficult job, it's worth doing.
Despite his unremarkable grades, he has an outstanding talent.
Although poor, they lived happily ever after.
How does these constructions differ from, say, 当然に?
～に modifies a verb, whereas ～ながら (sometimes) works like English "sentence adverbs". See this discussion.