Higher intakes of dairy milk are associated with greater risk of breast cancer, says a study.
The researchers, including those from Loma Linda University in the US, said: “It is estimated that one in eight women in the USA will develop invasive breast cancer during their lifetime, with 268 600 cases expected in 2020.”
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The study was conducted by Gary E Fraser, Karen Jaceldo-Siegl, Michael Orlich, Andrew Mashchak, Rawiwan Sirirat and Synnove Knutsen.
The researchers said the study gives “fairly strong evidence that either dairy milk or some other factor closely related to drinking dairy milk is a cause of breast cancer in women.”
The study was published in the ‘International Journal of Epidemiology’.
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In the study, the researchers noted that even relatively moderate amounts of dairy milk consumption can increase women’s risk of breast cancer by up to 80 per cent depending on the amount consumed.
A media report quoted Gary E. Fraser, study co-author from Loma Linda University, as saying: “Consuming as little as one-fourth to one-third of a cup of dairy milk per day was associated with an increased risk of breast cancer of 30 per cent.”
Fraser added: “By drinking up to one cup per day, the associated risk went up to 50 per cent, and for those drinking two to three cups per day, the risk increased further to 70 per cent to 80 per cent.”
In the study, the researchers said: “We identified 1057 incident breast cancer cases during 7.9?years’ average follow-up, 906 in post-menopausal women and 121 in women during premenopausal person-time.”
“Comparing medians of extreme dairy milk intake quintiles, risk at the higher intake was greater by 50% (uncalibrated analyses) and more than doubled in calibrated analyses.”
“There was an especially strong rise in risk up to 2/3 of an 8 ounce cup of milk (about 100 kcals of full-fat milk) per day, possibly less easy to demonstrate in other populations where fewer subjects consume dairy in this relatively low intake range,” the study said.
“Hence, data from this US Adventist, but otherwise diverse, population, suggest that either dairy milk or some closely-related unidentified factor(s) increases the risk of breast cancer,” it added.
The study was supported by the National Cancer Institute at the National Institutes of Health and the World Cancer Research Fund (UK).