In a nutshell, cancer cells love sugar. In fact, cancer cells have been shown to have 44 times more cellular receptors for sugar than healthy cells do. This may partially explain why studies have shown a direct connection between diabetes and many kinds of cancer. In fact, a joint US-Canadian study of 600 post-menopausal breast cancer patients found a definite connection between high insulin levels, obesity and higher incidence of the dis-ease.
The other connection between diabetes and cancer has to do with Insulin-Like Growth Factor 1 (IGF-1), a hormonal substance produced by the liver. IGF-1’s main job is to promote cell growth. While IGF-1 is vital for early childhood development, too much of it can be dangerous for adults.
A 2014 report published in the International Journal of Cancer found active “communication” between IGF-1 proteins, estrogen hormones and cellular receptor sites in the mammary glands, leading the German researchers to conclude that high IGF-1 levels could indicate a higher risk for ER-positive breast cancer. Still other studies have linked IGF-1 to lower immune function and higher occurrence of dense breast syndrome