Concern has been raised about the rising influence of public relations on scientific news coverage and the potential role of institutional sources in shaping news reports. This study uses quantitative content analysis and qualitative interviews to explore the influence of public relations activities on newspaper coverage of “superfoods” and, in particular, to explore the transparency of reporting of the sources of research funding. Superfoods were chosen as a case study because the term is applied to a wide range of foods with potential health benefits (e.g. foods high in antioxidants). Furthermore, foods labelled as “superfoods” have seen sharp increases in sales, suggesting a potential commercial incentive for such labelling. Analysis of a sample of news articles reporting superfoods revealed a considerable influence for media releases in shaping the content of reports, while less than a third of reports discussing research studies funded by organisations with a commercial interest in the findings mentioned the funding sources. Qualitative interviews confirmed the role of press offices in promoting research, particularly from scientific conferences, and suggest that scientific societies are applying less stringent criteria to studies selected for publication than in the past.