On the Coast – Over 55 Issue 26 I November/December 2018 - Page 6

The Link Between Obesity, Exercise & Breast Cancer with Dr Mary Ling, Central Coast Breast and General Surgeon A Sizeable Problem For the first time in history, there are now more overweight people than underweight people in the world. Globally, the number of obese people has risen from 105 million in 1975 to 641 million in 2014. The Hunter New England and Central Coast area has the third highest level of obesity in Australia, with over 60% of the population on the Central Coast being overweight or obese. While most people know obesity increases the risk of diabetes and heart disease, many are less aware that obesity increases the risk of many cancers: breast, oesophageal, stomach, bowel, liver, gallbladder, kidney, pancreatic, endometrial, ovarian and prostate. Obesity increases the risk of cancer through 3 main ways: 1. Inflammation. When there is a large collection of fat cells, immune system cells gather around the fat cells and release chemicals known as cytokines resulting in an inflammatory response. 2. Excess insulin: Overweight and obese people often have increased levels of Obesity & Breast Cancer The effect of obesity on the risk of breast cancer is not straightforward. There is strong evidence that obesity is associated with a markedly increased risk of hormone receptor positive breast cancer (the most common type of breast cancer) in postmenopausal women. Conversely, obesity is associated with a decreased risk of hormone receptor positive breast cancer in premenopausal women. This is not a reason to gain weight, but rather it means the pathway to developing breast cancer is different in younger women compared to older women and more research is needed to understand why. However, once diagnosed with breast cancer the prognosis is poorer for all women with obesity regardless of menopausal status. 6 S ENI O R S O N T H E C OAS T insulin and insulin-like growth factor in their blood. 3. Extra oestrogen: Fat cells produce significant amounts of oestrogen, and more fat cells mean more oestrogen is produced. Inflammation, excess insulin and extra oestrogen can cause cells to divide quicker than usual. Rapid cell division can result in DNA damage which can lead to the development of cancer. “For the first time in history, there are now more overweight people than underweight people in the world” – ​