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Research Finds Links Between Obesity, Diabetes, and Breast Cancer

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A very large Swedish study has found that women diagnosed with diabetes were more likely to be diagnosed with breast cancer compared to similar women not diagnosed with diabetes. The study also found a link between obesity in women older than 60 and higher breast cancer risk.

The results were presented at the 2011 San Antonio Breast Cancer Symposium.

Health care in Sweden is delivered through a national health system. This system makes it a little easier to track health outcomes and do research on links between health factors and cancer risk.

From a patient database of more than 1.5 million people, researchers looked at the health records of 2,724 women diagnosed with breast cancer and 20,542 similar women not diagnosed with breast cancer. They looked for links between breast cancer risk and both diabetes and obesity.

They found links between both health factors:

  • Breast cancer risk was 37% higher in women diagnosed with diabetes within the previous 4 years compared to breast cancer risk in women never diagnosed with diabetes.
  • Breast cancer risk was 55% greater in obese women older than 60 compared to younger women.

Other research has shown links between breast cancer risk and both diabetes and obesity. Doctors aren't sure exactly why having diabetes or being obese increases breast cancer risk. Higher insulin levels may be part of the reason. The hormone insulin helps our bodies regulate blood sugar. Insulin also helps cells grow. Many people who have diabetes and many older obese people tend to have higher-than-normal insulin levels (hyperinsulinemia). This is partially because their bodies no longer respond to normal insulin levels. Some experts think that higher insulin levels in diabetics and/or obese people may help breast cancer cells develop and grow, which increases breast cancer risk.

While your genetics play a role in both developing diabetes and obesity, these problems are due to an unhealthy diet and lifestyle in many people: too much sugar and too many simple carbohydrates, combined with not enough exercise. No matter your age, one of the best ways to avoid both obesity and diabetes AND help keep your breast cancer risk as low as it can be is to have a healthy diet and lifestyle:

  • eat a diet low in added sugar and other sweeteners and rich in fruits and vegetables
  • maintain a healthy weight
  • exercise regularly at a moderate intensity
  • avoid alcohol
  • don't smoke

A healthy diet and lifestyle can help you minimize both your breast cancer risk AND your risk of cardiovascular problems, such as heart attack and stroke.

Visit the Breastcancer.org Lower Your Risk section to learn more about breast cancer risk and steps you can take to make yours as low as it can be.

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