Q. Does the rule in CMOS 7.53 about non-English words hold for names of food and dishes, even if there is no English equivalent? For example, “He made rustici, Italian pastries.” “Her favorite dish is aloo paratha.” “My favorite dish is kacchi biryani.” Should “rustici,” “aloo paratha,” and “kacchi biryani” be in italics?
A. Good question! The purpose of using italics for non-English words in an English-language context is (a) to prevent them from being misunderstood as an unfamiliar English word (or as a typographical error) and (b) to signal a switch from English spelling style to another convention.
But italics aren’t automatically necessary for non-English words in an English context. In the context of your examples it’s obvious that the terms are names of food. The choice can also depend on the frequency of such words (isolated terms are more likely to merit italics) and on the perspective of the narrator or speaker. For example, a non-English term used in dialogue would rarely merit italics, since it can be assumed that it is part of the vocabulary of the person speaking it.
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]