That question really is almost pointless, because one or two a week will invariably lead to more. Once you let the yetzer hara for nicotene in, it will only grow. Ask any smoker who will tell you so. (even though most claim they are in “control”.
Also, if a person has another medical condition, such as diabetes, high blood pressure, cholesterol etc. even one once in a while can be very harmful.
all the young guys think they will be healthy forever, not thinking of the future, but then it catches up with them r”l. Don’t even start with one or two a week!