Is epidemiology ready for epigenetics?

The revellers depicted in the painting by the Dutch artist Judith Leyster (1609–60) (Figure 1) will not have given epigenetics a passing thought. Little were they to know that indulgences, such as drinking alcohol and smoking, would be contributing to their ‘exposome’ and marking their epigenome to potentially compromise their future health. The skeleton proffering an hourglass is perhaps a portent of the perils of such indulgence. Epigenetic alterations have been linked—sometimes tentatively—to a wide array of exposures and health outcomes, from smoking and alcohol to lung cancer and psychoses, and the field will surely witness a glut of further literature in the near future. Epigenetics has undoubtedly recently taken the world of medical research by storm, offering the promise of prediction, prevention and treatment of a wide spectrum of common complex diseases. The current special issue brings together a collection of reviews and articles with epigenetics as a common theme to consider the contribution that epidemiology can make in defining the role of epigenetics in common complex disease, or conversely, to ask the question—is epidemiology ready for epigenetics?