Background: Dietary elements and, in particular, dairy products have been implicated in the etiology of breast cancer. High saturated fat contents, contaminants such as pesticides, and insulin-like growth factor I (IGF-1) have been hypothesized as possible carcinogenic factors. In contrast, calcium, vitamin D, and conjugated linoleic acid (CLA) all are considered to reduce breast cancer risk. We aim to review the current epidemiological literature on the relationship between the intake of dairy products and breast cancer risk.
Methods: A Medline search was conducted using the key words breast neoplasms and dairy products. Further articles were obtained by cross-matching references of relevant articles. Thirty-nine case-control and 11 cohort studies were identified since 1981. Two meta-analyses and several review articles were also noted.
Results: Results from previous studies were analyzed and comparisons were made between each type of study. Controversy exists regarding this subject and we found conflicting evidence in recent literature regarding this hypothesis.
Conclusion: There is no substantial epidemiological evidence to support a significant link between the intake of dairy products and breast cancer risk.