Obesity Linked to 10 Cancers

You might know that being overweight or obese can negatively affect your heart health, energy levels, and even joints, but you may be shocked to learn that obesity also plays a role in cancerous growths. Within the last few years, the connection between obesity and cancer has become a hot topic among the general public, noted Neil Iyengar, MD, a specialist with the Breast Cancer Research Foundation and researcher at Memorial Sloan Kettering Cancer Center in New York City. Research has long supported the idea that obesity is a risk factor for cardiovascular disease and many other health concerns, but more recent findings suggest that being overweight is linked to developing certain types of cancer.

In the U.S. each year, around 28,000 men and 72,000 women are diagnosed with cancer associated with being overweight and obese, according to the National Cancer Institute (NCI). A report from the American Cancer Society suggests that excess body weight is responsible for over 544,000 cancer diagnoses, which is about 3.9% of all cancer diagnoses in the world.

Specifically, being overweight or obese has been connected to increased risk for developing 13 types of cancer, according to a 2016 study published by the International Agency for Research on Cancer. Obesity and weight-related diseases currently represent 40% of all cancers in the U.S., and ongoing studies indicate that fat centered around the waist is especially risky.

Unfortunately, the connection between body weight and cancer risk isn’t as simple as “lose weight, avoid disease” (nor does everyone who is overweight get diagnosed with cancer). The majority of studies on cancer and body weight don’t focus on individuals who lose weight but rather on people who can’t keep the weight off, so it’s difficult to determine exactly what your cancer risk would be if you started dropping weight. The best course of action is to avoid gaining any more weight, according to Graham Colditz, MD, Associate Director of the Institute for Public Health at Washington University in St. Louis. Still, losing a couple of extra pounds wouldn’t do any harm, either. Dr. Colditz noted that weight loss can reduce the risk of diabetes, heart disease, and stroke, so that may stand true for cancer as well, all of which is a compelling reason to get back into shape, balance a healthy diet with exercise, and avoid gaining more weight.

Below are 10 cancers that have been linked to obesity so far, as well as why those extra pounds might have an impact.


Kidney Cancer

The risk of renal tumors, the leading type of kidney cancer, is nearly twice as high in overweight or obese individuals than their healthy weight counterparts, according to the NCI. Insulin resistance may increase the risk of kidney cancer, and this pre-diabetes condition is not uncommon among overweight individuals. The kidneys are surrounded by fat, Dr. Iyengar noted, and inflammation of fatty tissue can have a powerful impact on the kidney. Further research is needed to better understand the link between fatty tissue and kidney cancer.

Liver Cancer

The risk of liver disease is also twice as high among overweight or obese individuals than normal-weight individuals. Researchers have considered several reasons why fatty tissue promotes tumorous growths, according to Dr. Iyengar. We know that Hepatitis C, a viral disease of the liver, can develop into liver cancer, as can cirrhosis (scarring on the liver), which is normally caused by hepatitis or chronic alcoholism. Both diseases cause chronic inflammation, Dr. Iyengar noted, similarly to inflammation associated with being overweight or obese. In either case, that inflammation may initiate the growth of cancerous cells.