Medical Research: What are the main findings of the study?
Prof. Michaëlsson: A high milk intake is recommended for the prevention of osteoporotic fractures but milk is also the major dietary source of galactose intake. The addition of galactose by injection or in the diet is an established animal model of aging by induction of oxidative stress and inflammation. Previous research results regarding the importance of milk intake for the prevention of fractures and the influence on mortality rates are conflicting. High milk intake was in our study associated with higher mortality in one cohort of women and in another cohort of men, and with higher fracture incidence in women. In subsamples of two additional cohorts, one in males and one in females, a positive association was seen between milk intake and both urine 8-iso-PGF2α (a biomarker of oxidative stress) and serum interleukin 6 (a main inflammatory biomarker).
Medical Research: What was most surprising about the results?
Prof. Michaëlsson: Since milk is promoted to prevent fractures and build strong bones, our study results may be seen as surprising.
Medical Research: What should clinicians and patients take away from your report?
Prof. Michaëlsson: Our results may question the validity of recommendations to consume high amounts of milk to prevent fragility fractures. The results should, however, be interpreted cautiously given the observational design of our study. The findings merit independent replication before they can be used for dietary recommendations.
Medical Research: What recommendations do you have for future research as a result of this study?
Prof. Michaëlsson: Our present investigation should not be evaluated in isolation and its merits should be judged in light of other study findings.