By David Liu, PHD

Saturday June 1, 2013 (foodconsumer.org) -- A medical review released in Feb 2013 in Experimental Biology and Medicine confirms calorie restriction and or physical activity, which lead to weight loss, protect against the development of a number of malignancies or cancers.

The report authored by L. Xie and W. Wang from University of North Dakota in Grand Forks, ND explains that calorie restriction and or physical activity leading to weight loss prevent tumor development and progression because they lower serum concentrations of insulin growth factor (IGF)-1 and other hormones, which are known to promote cancer.

The authors say obesity and overweight not only increase the risk for cardiovascular disease and type 2 diabetes, but also increase the risk for a variety of cancers.  And they also say studies have demonstrated that weight control via reducing calorie intake (calorie restriction) and or increased physical exercise help prevent cancer in animal models.

Studies have shown according to the review that weight loss due to calorie restriction and or increased energy expenditure lowered the circulating levels of insulin growth factor (IGF)-1 and other hormones such as insulin and leptin.

This action induced by weight loss can at least partially block the IGF-1 signaling pathways, which would otherwise promote cell proliferation and antiapoptosis, or simply put, promoting tumor growth.  Specifically, weight loss via calorie restriction and or physical exercise can help inactivate cell cycle progression and suppress tumor development through the reduction of serum levels of IGF-1.

Calorie restriction or physical activity can not only help prevent cancer, but also increase the odds of survival in cancer patients.  Research has shown that breast cancer patients who engaged in moderate physical activity tended to have a better chance to be a survivor (by definition, a survivor is a cancer patient who lives five years post-diagnosis).