MAY 1997 MONTHLY NEWLETTER

Georgetown Health Care Center Georgetown Pharmacy

A study of more than 4,000 Finnish women suggests that drinking milk could protect against breast cancer. In the 1960s and early 1970s government researchers in Finland questioned women aged 15 to 90 about their diets and then followed the women's health for the next 25 years. Epidemiologists who looked at the data found that the women who drank the most milk had only about half the risk of breast cancer than of those who drank the least.

As reported in Hippocrates (Vital Signs, February 1997), one reason for the scientists' surprised reaction to the finding was that the women in the study almost exclusively drank whole milk, which is very high in saturated fat. Researchers have thought that there was link between diets high in saturated fats and the risk of getting breast cancer. However, the way in which the study closely tracked the women's health and diets drew worldwide attention to the study. And, the study ruled out other factors that may have been responsible for the differences in breast cancer risk, such as smoking habits, weight, number of pregnancies, occupation, and other dietary patterns.

A couple of possible explanations of how milk night protect against breast cancer exist. First, some studies have suggested that galactose, the sugar found in all types of milk, slows the ovaries' production of estrogen. Higher levels of estrogen circulating in the body increase the risk of breast cancer. Thus, galactose could help in preventing the development of breast cancer. A second theory suggests that conjugated linoleic acid (CLA), a fat found in low-fat and whole milk, is the hero. Studies in animals have found that CLA suppresses breast tumors. Work is in progress to determine if this same effect is present in women.

There is evidence that women with asthma are much more likely to show up in emergency rooms just before and during their periods, suggesting a monthly cycle of asthma. Half of the women in a study were in the perimenstural phase the three days before menstruation and the first four days of bleeding when they had come to the hospital. It is during this phase that estrogen is the lowest, after having been at high levels for many days. Such shifts in hormone levels may trigger changes in the lungs that make flare-ups more likely. Patients with asthma may want to pay closer attention to control during that time of the month.