Separate Canadian studies have found that use of birth control is linked to increased risk of cancer and HIV and other sexually transmitted diseases.

The Journal of the National Cancer Institute reports that Dr. Steven Narod, chair of breast cancer research at Sunnybrook and Women’s College Health Sciences Centre in Toronto, has found that women who carry a certain gene should avoid prolonged use of the birth control pill or face an increased risk of breast cancer.

He said that women who carry mutations in the BRCA1 gene – about one in 200 Canadian women – and who use the birth control pill for more than five years are at a 50 to 80 per cent risk of developing breast cancer. Jewish women are at even greater risk, because one in 50 carry the mutated gene.

The study examined 2,600 women from 11 countries and found that women who used the pill before the age of 30 were at a greatly increased risk of contracting breast cancer. Narod was quoted in the Toronto Star: “Under the age of 25, I’d probably think of another form of contraception.”

Marjie Cohn Zacks, director of communication for the Ontario chapter of the Canadian Breast Cancer Foundation, told the Star that Narod’s findings show the need to review all “practices that increase the exposure to hormones over a woman’s lifetime.”

Narod’s research is just the latest to confirm the findings of Dr. Chris Kahlenborn, author of Breast Cancer: Its Link to Abortion and the Birth Control Pill, who has shown that birth control pills increase the risk for breast cancer in all women, regardless of the presence of the mutated gene BRCA1.

The link between oral contraceptives and breast cancer has been known since at least 1981, when Dr. M.C. Pike et al published an article in the British Journal of Cancer showing that young women who have abortions or use the birth control pill are at increased risk of getting breast cancer.

Hamilton’s McMaster University researchers have found that women who use popular abortifacient “contraceptive” devices such as the birth control pill and the contraceptive patch Depo-Provera could be at greater risk of infection for HIV and other STDs. They found that the hormone progesterone, which is used in the abortifacients, impairs the immune system’s ability to fight viral infections.

Presenting her findings at an Ontario HIV Treatment Network-sponsored international meeting of AIDS researchers in Toronto, Dr. Charu Kaushic, a professor of pathology at McMaster, said that the risk of HIV infection was 100 times greater in mice given progesterone compared to those that did not receive the hormone.