Newly published research finds that dairy milk consumption is linked to an increased risk of breast cancer in women. The new study led by scientists at Loma Linda University Health discovered that even small amounts of dairy milk intake can enhance women’s risk of breast cancer, up to 80 percent, in direct relation with the quantity consumed.
The paper titled “Dairy, soy, and risk of breast cancer: Those confounded milks” was published in the International Journal of Epidemiology.
The Amounts do not Matter
The first author of the paper, Gary E. Fraser, MBChB, Ph.D., said the survey 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.”
“Consuming as little as 1/4 to 1/3 cup of dairy milk per day was associated with an increased risk of breast cancer of 30 percent. By drinking up to one cup per day, the associated risk went up to 50 percent, and for those drinking two to three cups per day, the risk increased further to 70 percent to 80 percent,” Fraser said.
Dietary guidelines in the United States are currently advising for three cups of milk per day. However, “evidence from this study suggests that people should view that recommendation with caution,” Fraser said.
Approximately 53,000 North American women’s dietary consumption was analyzed for the research, all of whom were free of cancer and were surveyed for eight years. Dietary intakes were taken from food frequency questionnaires (FFQ), as well as numerous 24 recalls and a basic survey that had questions about demographics, family history of breast cancer, physical activity, alcohol intake, and so on.
When the researching period ended, there were 1,057 new breast cancer patients during follow-up. There were no definite correlations made between soy products and breast cancer, though. However, when compared to low or no milk consumption, higher amounts of dairy were linked to increased risk of breast cancer, independent of soy consumption.
Hormones in Dairy Milk Might Cause the Cancer
The authors noted that the discoveries had very little variation when comparing the consumption of full fat versus reduced or nonfat dairy milks, and there were almost no associations with cheese and yogurt.
“However,” Fraser said, “dairy foods, especially milk, were associated with increased risk, and the data predicted a marked reduction in risk associated with substituting soymilk for dairy milk. This raises the possibility that dairy-alternate milks may be an optimal choice.”
A dangerous impact of dairy is consistent with the recent AHS-2 survey, which says that vegans (not lacto-ovo-vegetarians) registered less breast cancer than non-vegetarians. Fraser explained that possible reasons behind these correlations between breast cancer and dairy milk might be the sex hormone content of milk. Breast cancer in women is reacting to hormones.
In addition, consumption of dairy and other animal proteins in numerous reports is also linked to higher blood levels of hormones, insulin-similar growth factor (IGF-1), which is believed to trigger particular types of cancer.
“Dairy milk does have some positive nutritional qualities,” Fraser said, “but these need to be balanced against other possible, less helpful effects. This work suggests the urgent need for further research.”