The media are a key element in being able to assess how the climate of public opinion regarding Complementary and Alternative Medicines (CAM) has evolved over the years. The aim of this study is to explore the variation of the media representations along 40 years (1979–2018) in Spanish newspapers to assess if the press has contributed to legitimise, delegitimise or maintain the status quo of these therapies. From quantitative and qualitative approaches, we evaluate the media attention, the narratives, linguistic terms and tone used, and the relations between them. Results indicate the media reporting on CAM has remained relatively stable during the first 37 years (1979–2015) of the study, but in the last 3 years a radical change has been observed in media attention, tone, language and arguments used. Media representations of this issue evolves from a period of low media attention (1979–2015), in which CAM was legitimised, to another period of high media attention (2016–2018), in which CAM was delegitimised.