Birth control has long term effect on hormone exposure
Researchers at North Carolina State University and the Centers for Disease Control and Prevention have produced the first link between a species of bacteria most commonly found in sheep and human illness. Dr. Edward Breitschwerdt, professor of internal medicine at NC State’s College of Veterinary Medicine, and NC State colleague Dr. Ricardo Maggi isolated the
Full Post: Discovery of new bartonella species that infects humans
Researchers at Wake Forest University School of Medicine may be one step closer to understanding why past oral contraceptive use dramatically lowers the risk of ovarian and uterine cancers later in life.
While studying the effect of post-menopausal dietary soy consumption on estrogen metabolism in cynomolgus monkeys, Latanya M. Scott, Ph.D., discovered that monkeys who had been given birth control earlier in life had a reduced amount of estrogen excreted in their urine. The research was done in collaboration with Xia Xu, Ph.D., and Timothy Veenstra, Ph.D. at Science Applications International Corporation-Frederick, Inc., in Frederick, Md., who have developed novel methods for analysis of urinary estrogens.
The discovery was particularly noteworthy because it was found three years after oral contraceptive treatment was stopped, roughly the equivalent of a decade of life in a human. While researchers have known for many years that past oral contraceptive use significantly lowers the risk of ovarian and uterine cancers later in life, this new observation in monkeys may shed light on the mechanism behind the cancer-protective effect of the treatment. Past oral contraceptive use appears to result in a long-term change in the way the monkeys’ bodies process hormones. While researchers don’t yet understand the precise mechanism by which hormone levels are being affected, they do know that both the level of estrogen in the blood and the amount of estrogen being excreted in urine are lowered with past oral contraceptive use, which may mean that the oral contraceptive use is somehow leading to a diminished synthesis of estrogen.
The study appears in this month’s issue of Cancer Epidemiology, Biomarkers and Prevention.
“Hormone exposure has long been known to be important in cancer risk,” said J. Mark Cline, D.V.M., Ph.D., and senior researcher on the project. “These effects are robust, and we believe this discovery could be translated fairly quickly into a study in women. If our results are confirmed to also occur in women, they could change the way we look at oral contraceptives and cancer risk,” added Cline, a professor of pathology and comparative medicine.
With funding from the National Institutes of Health, researchers began with 181 premenopausal cynomolgus monkeys and followed them for seven years in a study designed to look at hormone effects on many aspects of female health.
Half of the monkeys were given a birth control treatment of triphasic estrogen and progestin, marketed by Wyeth Pharmaceuticals as TriphasilTM, for 26 months. At the end of the premenopausal phase of the study, the animals underwent surgery to have their ovaries removed, making them surgically menopausal.
The postmenopausal monkeys were then divided into three dietary intervention groups to evaluate the effects of soy on hormone metabolism.
Urine samples were collected from each monkey during the 35th and 36th months of the postmenopausal phase of the study and frozen for subsequent analysis of metabolite concentrations.
Lab results showed that the premenopausal use of oral contraceptives resulted in significantly lower levels of most estrogen metabolites three years after surgical menopause. Among the most abundant metabolites, percent changes ranged from a 25 percent reduction in E1 to a 50 percent reduction in 2OHE1 with oral contraceptive administration. Postmenopausal dietary isoflavones induced fewer significant effects on postmenopausal estrogen metabolite concentrations.
“The magnitude and persistence of oral contraceptive effect really surprised us,” said Cline, a diplomate of the American College of Veterinary Pathologists. “It tells us that there may be a new and potentially strong cancer-protective mechanism at work. This could open new doors of inquiry in the field.”
All procedures involving the animals were conducted in compliance with state and federal laws, standards of the U.S. Department of Health and Human Services, and guidelines established by the Wake Forest University Animal Care and Use Committee.
In addition to the National Institutes of Health, the study received funding from the National Cancer Institute and National Center for Complementary and Alternative Medicine. Co-researchers were lead author Latanya M. Scott, Ph.D., Charles E. Wood, D.V.M., Ph.D., Thomas C. Register, Ph.D., Nancy D. Kock, D.V.M., Ph.D., and Janet A. Tooze, Ph.D., all of the Wake Forest University School of Medicine, and Xia Xu and Timothy D. Veenstra, both of Science Applications International Corporation-Frederick, Inc., in Frederick, Md.
The combination of estrogen plus progestin, which women stopped taking in droves following the news that it may increase their risk of breast cancer, may decrease their risk of colorectal cancer, according to a report published in the January issue of Cancer Epidemiology, Biomarkers and Prevention, a journal of the American Association for Cancer Research.
Full Post: Estrogen plus progestin therapy may decrease risk of colorectal cancer
Family planning is taken very seriously these days and it should be because of the increasing population. The young couple these days are very careful before getting pregnant, they think about everything before conceiving. Developed and developing countries both have taken measured steps to reduce the unwanted pregnancies. Therefore these days the contraceptive are used
Full Post: Birth Control Pills - A Triviality
Two pregnancies and six cases of intermenstrual bleeding have been described in women using oral contraceptives, attributed to the use of Diflucan. This interaction (if such it is) is rare. Two pregnancies have been reported, despite the use of oral contraceptives, attributed to an interaction with single 150 mg doses of Diflucan. Intermenstrual bleeding has also
Full Post: Diflucan and oral contraceptives
Women who suffer from migraines may take at least some comfort in a recent, first-of-its-kind study that suggests a history of such headaches is associated with a significantly lower risk of breast cancer. Christopher I. Li, M.D., Ph.D., and colleagues at Fred Hutchinson Cancer Research Center report these findings in the November issue of Cancer
Full Post: Migraines linked to lower risk of breast cancer
For breast cancer survivors, the idea of taking estrogen pills is almost a taboo. In fact, their doctors give them drugs to get rid of the hormone because it can fuel the growth of breast cancer. So these women would probably be surprised by the approach taken by breast cancer physician Matthew Ellis, M.B., Ph.D.,
Full Post: Estrogen therapy can help control metastatic breast cancer