Doctors in Finland investigating the links between different foods and cancer risk followed the progress of 4,697 women aged 15 and over for 25 years. All were initially free of cancer but by the end of the study the disease had been diagnosed in 88 women.
The researchers measured consumption of milk and other foods by means of interviews and questionnaires on dietary history. Other factors such as smoking, number of childbirths, occupation, bodyweight and geographical area were taken into account.
A paper in the British Journal of Cancer reports there was a "significant inverse gradient between milk intake and incidence of breast cancer".
The researchers are not sure why milk should lessen breast cancer risk, but suspect nutrients such as lactose and calcium had a protective effect. Attention has also focused on CLA, conjugated linoleic acid, which is present in high concentrations in milk fat. Animal trials have shown that CLA suppresses mammary tumours.Reuse content