A relationship has been uncovered between high levels of insulin and breast cancer.
Postmenopausal women with hyperinsulinemia were twice as likely to develop breast cancer when compared to women with the lowest levels of insulin.
Researchers from the Women’s Health Initiative (WHI) followed more than 93,000 postmenopausal women beginning in 2004. Some were selected who did not have diabetes, others had breast cancer.
Women not on hormone therapy, such as estrogen and progestin, made up the majority of participants. After assessing fasting insulin levels, body mass index, and estradiol levels researchers found a link between the highest levels of insulin and a risk for breast cancer. The link was found only among women not using hormone therapy.
In addition, researchers found an association between the risk for breast cancer and obesity, among those not on hormone replacement therapy (HRT). The study is published in the Journal of the National Cancer Institute.
Hormone Replacement Therapy
In 2002, the Women’s Health Initiative began a large clinical trial of hormone replacement therapy in postmenopausal women, but the study was stopped early because of the increased risk of developing breast cancer. Many women were advised by their doctors if they wanted to continue taking HRT, to take the lowest dose possible.
Since the 2002 warning about HRT, the rate of breast cancer has declined in the U.S. from about 210,000 women diagnosed each year, to about 190,000- a number that has stayed steady since 2005. The noted decline in breast cancer is part of a new study published Wednesday in the New England Journal of Medicine.
Exercise
The American Cancer Society reports on a study today about exercise. Not only does it improve mood, keep your weight in check, but working up a sweat can also help prevent certain types of breast cancer.
Researchers at the German Cancer Center and University Hospitals of Hamburg-Eppendorf reviewed the exercise levels of about 10,000 women. They were asked how often they exercised from the 30 to 49 year old age group and then after they were age 50. Not only were those who engaged in exercise less likely to be breast cancer patients, but the women who added more exercise later in life reduced their breast cancer risk even more than the women in their 30s.
The Women’s Health Initiative suggests as little as 1.25 to 2.5 hours of exercise per week, such as brisk walking, can reduce a woman’s risk of breast cancer by 18 percent. Walking up to ten hours a week reduces the risk a little more, according to the American Cancer Society.
A good guideline is 45 to 60 minutes of physical activity five or more days a week. #