"Metabolic syndrome" is a term doctors use for people who have a combination at least three of the following problems: obesity in their belly area, blood sugar difficulties (diabetes or pre-diabetes), elevated lipids (such as high cholesterol or high triglyceride levels), and high blood pressure. Research found that postmenopausal women who develop metabolic syndrome have an increased risk of breast cancer, both invasive and non-invasive. Metabolic syndrome has already been shown in other research to increase the risk of developing diabetes and coronary heart disease, but this is the first research to look at the link between metabolic syndrome and breast cancer risk.
This research was one small part of the large and comprehensive study referred to as the Women's Health Initiative, or WHI. For this particular study the researchers followed nearly 4,900 postmenopausal women for an average of 8 years. 165 of these women developed breast cancer, most of which was invasive. The researchers found that breast cancer was nearly twice as likely to be diagnosed in women who developed metabolic syndrome during the 3 to 5 years before the cancer was diagnosed, compared to women who did not develop metabolic syndrome during that same period of time.
When the researchers looked at how individual parts of the metabolic syndrome affected risk among the women followed in the study, they found that elevated blood sugar levels, elevated triglyceride levels, and elevated blood pressure were problems each independently linked to an increased breast cancer risk.
The researchers aren't sure exactly how having the metabolic syndrome increases breast cancer risk. Insulin is a hormone that helps our bodies regulate blood sugar. Insulin also contributes to the growth of cells. People with metabolic syndrome tend to have insulin levels that are higher than normal (hyperinsulinemia), in part because their bodies no longer respond to normal levels of insulin. The researchers think that increased insulin levels in people with metabolic syndrome may promote the development and growth of breast cancer cells and so increase breast cancer risk.
While genetic factors contribute to the development of metabolic syndrome, this condition is largely the result of an unhealthful diet -- too many calories, too much fat, and too many simple carbohydrates -- combined with inadequate levels of exercise. Regardless of your age, the best way to avoid developing the metabolic syndrome AND help keep your breast cancer risk as low as it can be is to adopt and consistently stick to a healthy diet and lifestyle:
- Eat a diet low in fat and rich in fruits and vegetables.
- Maintain a healthy weight.
- Engage regularly in moderate-intensity exercise.
- Avoid alcohol.
- Don't smoke.
Visit the Breastcancer.org Lower Your Risk section to learn more about breast cancer risk and steps you can take to lower that risk.