How could obesity lead to cancer?
It's very clear that there is a link between cancer and obesity. But it's still not completely understood how exactly obesity causes cancer. Research so far has identified three leading explanations. It's helpful to start by knowing what fat is, and what it does in the body.
Fat in the body has two main functions. It acts as a store of energy. And it's constantly spreading information and instructions to the rest of your body. These messages affect things like cell growth, chemical reactions in cells, and the body’s reproductive cycles. So fat doesn’t just sit there doing nothing. It's active, telling your cells what to do. And if there is too much fat in the body, then the signals it sends around the body can cause damage. It's likely that this is how obesity raises the risk of cancer. Growth hormones- too much body fat can cause levels of insulin and other growth factors to rise, which can tell cells to divide more often. This raises the chance that cells will change and lead to cancer.
Inflammation- when there are more fat cells in the body, specialised immune cells go to the area, possibly to remove dead and dying fat cells. They release a cocktail of chemicals called cytokines, which can lead to inflammation. This makes cells divide faster, and when this happens over a long time it can raise the risk of cancer. Sex hormones- after the menopause, estrogen made by fat cells can make cells divide faster in the breasts and womb (two of the cancer types most closely linked to obesity), increasing the risk of cell faults and cancer.