"We found evidence for the often-questioned relationship between milk consumption and cancer, yet when we used genotypes to verify this relationship, there was no corroboratory evidence," Timpson said. "This does suggest that the basic findings may be subject to the kinds of biases and inaccuracies that often upset epidemiological research, but that this study would need to be undertaken on a much larger scale in order to verify these initial findings."

Johanna Lampe, Ph.D., an editorial board member of Cancer Epidemiology, Biomarkers & Prevention who is not associated with this study, said this study demonstrates the complexities of evaluating dietary exposures and cancer risk.

"These results are a reminder to proceed with caution when interpreting data that suggest an association between intake of specific foods and risk of a particular cancer. Human diet is complex and typically involves adherence to certain dietary patterns that are also tied to other lifestyle behaviors," said Lampe, full member and nutrition scientist in the division of public health sciences at Fred Hutchinson Cancer Research Center, Seattle, Wash.

Source: American Association for Cancer Research