According to a new report by the American Institute for Cancer Research, "greater body fatness is a probable cause of ovarian cancer in women."

The AICR looked at 25 studies that involved data on 4 million women, 16,000 of whom had ovarian cancer. They found a link between body fat and ovarian cancer-  a link that the AICR and the National Cancer Institute had long suspected.

There are many reasons why fat may raise cancer risk: Fat cells secrete estrogen, a hormone that can help fuel cancer. People who are overweight or obese have overall higher levels of inflammation, which can affect heart disease and cancer risk alike. Fat cells produce other hormones such as leptin and growth factors that may affect the out-of-control cell growth that underlies cancer.

The AICR investigated all possible causes of ovarian cancer, like milk, eggs, coffee, and meat to name a few, but body fat was the only one to provide evidence showing a possible cause.

"There is so much we don't know about preventing ovarian cancer," said Dr. Elisa Bandera of the Rutgers Cancer Institute of New Jersey, who helped write the study, "But now we can tell women that keeping to a healthy weight can help protect against this deadly disease."

[NBC]