White oak (Quercus alba) has a long history of use in traditional herbal medicine, particularly among Native American and early European settlers in North America. The bark and other parts of the white oak tree have been employed as an astringent, which means they are used to contract body tissues and reduce bleeding or secretions. In the context of bladder health, white oak bark was traditionally used to address issues such as urinary tract infections (UTIs), diarrhea, and inflammation, due to its high tannin content. The astringent properties were believed to help "tone" the mucous membranes of the bladder and urinary tract, providing symptomatic relief from irritation or mild infections.

However, there is very limited scientific research to directly support the use of white oak for bladder health or urinary tract conditions. Most of the available evidence is anecdotal or based on traditional practices, rather than clinical studies. The rating of 1 reflects that while there is a historical precedent for its use, there is little modern scientific validation. Modern herbal medicine texts do occasionally mention white oak for urinary tract support, but it is much less common compared to other herbs with stronger research backing. As such, the contemporary use of white oak for bladder support is primarily justified by tradition rather than scientific evidence.