Studies in the Journal of American Medical Association may cause women to rethink asking for antibiotics as possible links to breast cancer have been brought up.

It all started with a study done in Finland in 2000 that reopened a link between breast cancer and antibiotics.  This study sparked interest in the University of Washington school of Medicine to examine data collected on over 10,000 women enrolled in a large health plan in the state.

Two groups were studied; one group consisted of 2,266 cases of women diagnosed with invasive breast cancer.  The second nearly 8,000 women randomly selected with no breast cancer.  Researchers used health plan data to determine the number of antibiotic prescriptions each person was given, as well as the total number of days that each woman used antibiotics over a 17 year period.

The data was shocking as it showed the risk of breast cancer was doubled among women who received 25 or more prescriptions for any antibiotics when compared to women who took none.  The group of women who took from 1 to 25 prescriptions increased their risk by one and a half times those that took none.

Death from breast cancer was highest among the women with a high rate of cumulative days on antibiotics.  According to the Washington researchers this does not definitely prove that antibiotics cause breast cancer.  There are many other factors to consider such as the possibility that the illness being treated by the antibiotics may play a roll in breast cancer development as well.

As a side note; as much as eighty percent of the total antibiotic production in the U.S. is used in agriculture.  Dairy, livestock and poultry animals are injected or fed antibiotics not for illness but to promote growth.  As these products make their way into the food chain everyone is getting exposed to antibiotics without a prescription.

A University of Maryland study supported the conclusion that agricultural antibiotic use may be introducing new antibiotic-resistant strains of bacteria into the human population.