There are a number of factors that contribute to developing cancer, including your genetic makeup and lifestyle habits. According to recent research, the leading preventable risk factor when it comes to developing cancer isn’t tobacco use or sun exposure — it’s obesity.
Health spoke to researchers at Yale University who concluded there is a clear link between being overweight or obese and an increased risk of several types of cancer.
“We know that a good third of cancers are associated with our lifestyle behaviors, such as what we eat, how much we exercise and, collectively, our weight,” Melinda Irwin, Ph.D., director of Cancer Prevention and Control at Yale University, told Health. “And obesity is now the leading modifiable risk factor, even ahead of tobacco use, that’s associated with cancer risk and mortality.”
But how exactly does obesity increase cancer risk? Having too much body fat puts the body in a state of constant inflammation, and inflammation is known to increase the development of cancer cells. Meanwhile, insulin resistance — a condition often developed from the high-sugar diets that lead to obesity — is proven to trigger cell proliferation, which is linked to specific cancers.
The American Cancer Society explains that while there are many factors that contribute to developing cancer, certain cancers are clearly linked to being overweight. Cancers that are directly linked to excess weight include: breast (in women past menopause), uterine, colon and rectum, esophagus, kidney and pancreas. Meanwhile, cancers of the cervix, liver, gallbladder and ovaries, along with aggressive prostate cancer, are all more likely to develop in the overweight.
Irwin tells Health that the type of cancer most directly linked to obesity is uterine cancer. “There’s probably a sixfold higher risk of dying of uterine cancer for those with a high BMI versus those with a low BMI.”
While this new research implies that weight gain and obesity are more dangerous for your health than you previously imagined, it also means there’s something you can do to actively decrease your cancer risk. Losing weight or maintaining a weight that’s healthy for your body can increase your chances of not developing these cancers. “[Preventing weight gain] is going to significantly change your risk for cancer and, importantly, for overall mortality,” Irwin says.
The good news: There’s no time like the present to figure out the fitness routine and diet that works best for you.