Now, having said that shoes don't cause bunions, let me clarify by saying that shoes can (and often do) make them much worse. Wearing shoes with high heels can significantly increase the stress on the big toe joint. All of that increased stress can lead to instability in the joints of the mid-foot that actually accelerates the speed with which a bunion forms. So although it might have taken 40 or 50 years to develop a bunion wearing flat shoes, the same person may develop bunions 10 to 20 years earlier just because of the extra strain caused by high-heeled shoes.
Even if the shoes don't have a gigantic heel, the shape of the shoe itself can also contribute to the early formation of a bunion. For example, cramped pointy toe shoes can push the big toe into a position that does contribute to the development of a bunion. In addition, tight shoes and those with a seam that runs right over the bump can make the bunion much more painful and irritated. Often times, tight shoes will cause bursitis or inflammation of the big toe joint. When this happens the bunion can become red, tender and inflamed.
The obvious solution to this is to avoid shoes that are likely to either cause bunions by increase the amount of stress on the big toe joint. This means wear sensible shoes. Shop for shoes that have only a moderate heel; two inches or less. Use common sense. If you have a function to attend such as a wedding, formal ball or charity event, it is unlikely that one night in pretty shoes will do any long-term harm. Just don't wear stilettos every day. Also make sure that you avoid shoes with seams or stitching that will press or rub on the big toe joint further irritating the bunion.
So what is the bottom line on shoes and bunions? Well, have fun, shop for shoes, dress up when you need to but don't go overboard on the high heels or pointy shoes. Even though you might not be able to do much about the genes that you inherited, you don't necessarily have to end up with painful bunions.