Two or More Daily Glasses of Milk May Raise Ovarian Cancer Risks
May 5, 2000 (Boston) -- A milk mustache may not be the most appropriate fashion statement for women concerned about their health, say scientists from Harvard Medical School. The latest finding from an ongoing study of more than 80,000 nurses suggests that women who drink two or more glasses of milk a day have a 44% higher risk of getting ovarian cancer than women who rarely drink milk.
Switching to low-fat or skim milk may not help, says Kathleen M. Fairfield, MD. Most of the milk drinkers in the nurses' study drank skim or low-fat milk. While chugging milk increases the overall risk of getting any type of ovarian cancer by 44%, it increases the risk for the most common type of ovarian cancer -- called serous tumors -- by 66%, Fairfield says. Ovarian cancer, she says, is the fifth most common cancer among American women.
Fairfield suggests that neither the fat nor the calcium content of milk increases the risk. Lactose, or milk sugar, appears to be the most likely culprit. Every 8-ounce glass of milk -- any type of milk--- contains about 11 grams of lactose.
In the body, lactose is broken down into two simple sugars -- glucose and galactose. In this case, Fairfield says that she and her colleagues think it may be the galactose that is in some way linked to cancer growth. That means lactose-free milk wouldn't be a good substitute because it contains galactose, she says.
Currently, women are advised to increase their consumption of dairy products to protect against osteoporosis, and Fairfield says those "osteoporosis recommendations are at just about the same consumption level that we are associating with ovarian cancer." What's a woman to do?
Because these results have not yet been reviewed by other scientists or published, Fairfield tells WebMD she is reluctant to make any recommendations. When asked by another physician how she would advise a 45-year-old female patient, Fairfield says she won't tell women who drink milk to stop. "But if a woman is concerned about osteoporosis but isn't currently a milk drinker, I am going to start her on calcium supplements."