Many factors are thought to potentially influence the development of cancer, including genetics, environment and various lifestyle choices. It is essential that we look to recommendations from leading authorities who base their recommendations on the totality of evidence. The leading cancer authorities worldwide, including the World Cancer Research Fund’s Cancer Prevention Recommendations (May 2018) do not advocate the exclusion of dairy for cancer prevention or treatment. In fact, milk, yogurt and cheese are nutrient rich and recommended as part of a healthy balanced diet. The Irish healthy eating guidelines, which includes the ‘milk, yogurt and cheese’ food group, are advocated by the Irish Cancer Society as part of their recommendations to reduce the risk of cancer.
The misconception surrounding dairy and cancer stems mainly from a belief that there are hormones or proteins in cow’s milk which could cause harm. To note, artificial hormones for growth promotion are banned in the Irish dairy industry. Traces of natural hormones can be present in a range of foods but get broken down by digestion. In milk, the amounts are negligible, with oestrogen traces at less than 1 % of the tolerable upper limit set by the World Health Organisation. Casein is an important dairy protein, which carries nutrients in milk. There is no convincing scientific evidence to suggest that casein causes cancer.