The Million Women Study

Over a million women in the UK have joined a long-term study that regularly asks them about their health, lifestyle, and medical history, and the research team actively responds to thousands of questions and comments from participants. This matters because the study is designed to provide reliable, large-scale evidence on modifiable factors—things like diet, exercise, hormone use, and smoking—that directly affect women’s health. Many health recommendations are based on smaller or shorter studies, and the sheer size and duration of this project allow researchers to detect subtle but important links between everyday behaviours and serious diseases such as cancer, heart disease, and stroke. If the research succeeds, it will produce clear, trustworthy information that women and their doctors can use to make informed decisions about prevention and lifestyle. The findings are already being shared through public meetings and plain-language summaries on the study’s websites, so the results reach people directly rather than staying locked in academic journals. This is not a laboratory experiment with an immediate practical application—it is a long-term observational study that builds a detailed picture of how real women live and what keeps them healthy over decades. Similar large-scale cohort studies have in the past transformed public health advice on smoking, alcohol, and screening.