It is acceptable to discuss virtually any topic––the weather, sports, news events, fashion, books, art exhibits, travel, even politics and religion––if you frame the question appropriately. “What do you think of the Democrats’ health reform plan?” is a perfectly acceptable conversational gambit. “Don’t you think the Democrats’ health reform plan is ridiculous?” is not acceptable. Similarly, a person can disagree politely with the other person’s view by saying “I don’t agree with you” or “It seems to me that…” rather than “that’s nonsense!”
If there are subjects one should avoid in polite conversation, they include comments about a person’s age and physique and questions requiring professional expertise. You should never ask a person, “How old are you?” or “How much do you weigh?” Nor is it acceptable to comment on a woman’s measurements or her sexual nature, ever. While this may be done in Japan in private conversations and on television, it is considered in poor taste in America. It is also not acceptable to ask a lawyer or a doctor for the kind of advice that they offer in their offices on weekdays. It is fine to ask a doctor about general medical topics, but do not ask for diagnosis of a personal ailment at a cocktail party!
It is also best to avoid discussing health maters, death, financial difficulties, career traumas and scandals in anyone’s family.