From 12 to 18 years of age, students in Spain go from a compulsory stage (ESO) to an optional stage (hight school), where issues related to bioethics are addressed in different subjects. Our work analyzes current textbooks from prestigious Spanish publishers in the humanities subjects of "Education in Civic and Ethical Values", "Philosophy", and "Catholic Religion". The objective has been to analyze, following a rubric, the quality and quantity of ethical and bioethical content related to human dignity. Our research provides, as conclusions, first of all, the widespread absence of an anthropological foundation of human dignity, equated with legalized "human rights" and often with the value of other living beings; the uncritical acceptance of the 2030 agenda; the omission of moral judgments in bioethical dilemmas that arise at the beginning and end of human life. Finally, we also detect the dissemination of the an absolute biocentrism, as a way of overcoming anthropocentrism, without considering the option of a relative biocentrism that does not reduce the human being to simple biology.