Breast Cancer Linked to Higher Insulin Levels
A new analysis of 5450 women shows that higher circulating insulin levels lead to twice the likelihood of breast cancer. Past studies have shown that obesity and diabetes contribute to breast cancer. The newest study more clearly defines the role of high insulin levels and breast cancer risk.
Researchers at Albert Einstein College of Medicine of Yeshiva University looked at women enrolled in the Women's Health Initiative to determine that higher insulin levels, found in postmenopausal women is a contributor to breast cancer, even among women who are not overweight.
Lead study author Geoffrey Kabat, Ph.D., senior epidemiologist in the department of epidemiology and population health at Einstein says, "This finding is potentially important because it indicates that, in postmenopausal women, insulin may be a risk factor for breast cancer that is independent of obesity.”
Insulin is a hormone that controls glucose levels, and is secreted to normalize blood sugar levels in the body. It also helps with digestion. It is released by the pancreas every time we eat. The amount of insulin circulating depends on the type of food we eat. Insulin has been found in animal models to promote tumor growth. Eating a healthy diet keeps our insulin levels from becoming higher, now found to be a risk factor for breast cancer.
The researchers divided women into three groups, separated by insulin level measurements. They found that women with the highest insulin levels had twice the risk of developing breast cancer. The current study analyzed insulin levels in the women at one, three and six years, as well as at baseline - previous studies only used baseline insulin levels.
Of interest, preliminary findings of the study revealed that lean women were most susceptible to breast cancer if their insulin levels were elevated. Those results could indicate another reason that healthy eating and regular activity is important for post-menopausal women. Keeping insulin levels controlled may be another factor that can reduce our risk of breast cancer.