Alcohol and Breast Cancer

As a result of recent research carried out in Germany it has been shown that light drinking may have a protective effect. However, the new findings leave open the possibility of a real increased risk,( although modest) of breast cancer among those women who binge drink. The researchers point out that several subsequent studies with more detailed information about life time drinking habits have not consistently supported the idea of the risk rising in parallel with dose -certainly not at light to moderate levels.

Subjects for the new "case controlled" study by Kropp S., Becher H., Nieters A and Chang-Claude J., were 700 women aged up to 50 years with newly diagnosed breast cancer. The women were seen at 38 hospitals which served 2 different regions of Germany and they were compared with a larger number of women who were disease free and who matched for age and region. By comparing the 2 groups of subject the researchers could attempt to discern factors which could explain why the disease had developed in the first group but not in the second.

A questionnaire was completed by all the participants providing information on a wide range of matters, from smoking to hormone replacement therapy , which might be relevant to the emergence of breast cancer. The womens average intake of beer, wine, spirits and other beverages was recorded after the women recalled their drinking habits during the years 15-20, 20-30 and 30-50.

Compared with non-drinkers, the data showed that women who consumed on average 1-5, 6-11 or 12-18 grammes of alcohol per day during their lifetimes had a 30% lower risk of breast cancer. However, those with an intake of 31 grammes (i.e. just under 4 units) or more per day were twice as likely as abstainers to develop the disease. In the latter group there was no information about precise levels of alcohol, which may have included heavy drinkers.

Previous research, which for the most part was conducted not on human subjects but on cancer cells, highlighted resveratrol as the substance in red wine which may interfere with transformation of normal healthy cells into cancer. Therefore, the evidence of a protective effect of light drinking was unexpected and seemed to be primarily associated with the consumption of wine, the preferred drink among participants.