如今,美食家们对吃提出了更高的要求。他们不仅要观色、闻香、尝味、赏形,而且还要求食物具有养生方面的特色。我想,家乡的萝卜饼完全具备这几个方面的条件,人们不是常说吗——“鱼生火,肉生痰,青菜萝卜保平安”,养生的功能,让我更加喜爱它了。
This is from the Standard Course Book of HSK5, section 19.
What is the meaning of 人们不是常说吗? People not often say (Google translate) or people often say (Baidu translate)? Also, what is this long dash —— (without space)?