Carolyn McAnlis, Dietitian and Pink Hope Ambassador discusses body weight and cancer risk.
We often hear the side effects of obesity in the media: diabetes, cardiovascular disease, high blood pressure – the list goes on. But did you know that list also includes cancer? Being overweight or obese (classified as having a BMI of 25 or greater) puts you at risk for cancers like breast and colon, as well as endometrial among others.
Why would excess body weight put us at risk for cancer? It’s all in the fat. Fat cells produce hormones and inflammatory secretions, so if you have excess fat you will have an increase of these in your blood these as well. The hormones, like oestrogen and adipokines, actually stimulate cell (and tumour) growth. Obese people also have raised levels of insulin in their blood which may promote tumour development. Further, obese people have a chronic, low level of inflammation throughout the body due to excess weight.
While some of the reasons why obesity is linked to an increased incidence of cancer are not fully known, research does show that, for example, women who are overweight or obese have two to four times the risk of developing endometrial cancer than women of a normal weight, regardless of menopausal status. The specific science hasn’t been fully worked out, but the link is clear.
Being at a healthy body weight can also improve cancer survival; this has been shown especially in breast cancer.
In an article in the Sydney Morning Herald on August 26, 2013, Dr Marina Reeves, National Breast Cancer Foundation Fellow at the University of Queensland’s Cancer Prevention Research Centre, stated that, “there’s clear evidence that if a woman is obese at the time she’s diagnosed with breast cancer either before or after menopause, not only is the cancer more likely to recur but she’s also less likely to survive.”
Maintaining a healthy weight through adulthood is crucial for not only preventing cancer (among the many diseases that go hand-in-hand with obesity), but also for increasing survival if diagnosis does occur. This is especially important information for high-risk women who decide against risk-reducing surgery.
Maintaining a healthy body weight, by eating well and exercising, is one of the best things you can do to reduce your risk and even improve your survival if you are diagnosed later in life.
Calculate your BMI here: http://www.nhlbi.nih.gov/guidelines/obesity/BMI/bmicalc.htm
More about Obesity & Hormones: http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Obesity_and_hormones
SMH Article: http://www.smh.com.au/lifestyle/diet-and-fitness/blogs/chew-on-this/why-keeping-off-the-kilos-reduces-cancer-risk-20130826-2skso.html
National Cancer Institute (US): http://www.cancer.gov/cancertopics/factsheet/Risk/obesity
American Cancer Society: http://www.cancer.org/acs/groups/cid/documents/webcontent/002578-pdf.pdf