Stomach, liver, gall bladder, pancreas, ovary, brain (meningioma), thyroid, and blood (multiple myeloma). These eight additional types of cancer may be related to carrying excess body weight, according to researchers, who also found that these risks were similar for both men and women, and consistent across geographic regions. These findings are published in the August 25, 2016 issue of The New England Journal of Medicine.
“The burden of cancer due to being overweight or obese is more extensive than what has been assumed,” said cancer prevention expert Graham Colditz, MD, DrPH, Washington University School of Medicine in St. Louis, who chaired the World Health Organization’s International Agency for Cancer on Research (IARC) Working Group, based in France. This group of researchers had earlier found that excess weight was linked to a higher risk of colon, esophageal, kidney, breast, and uterus cancers in 2002.
“Many of the newly identified cancers linked to excess weight haven’t been on people’s radar screens as having a weight component,” added Dr. Colditz, who, with fellow researchers at the IARC, conducted a review of over 1,000 studies of excess weight and cancer risk.
For most of these cancers, they found a positive dose-response relationship between excess weight and cancer risk. The higher the BMI, the higher the individual’s risk of cancer. This increased risk may be related to the link between excess weight and the possible overproduction of estrogen, testosterone, and insulin by the body, as well as by increased inflammatory processes, all of which are known to fuel cancer growth.
These new findings from the IARC may be of particular relevance in light of the fact that about 640 million adults and 110 million children worldwide are obese. In the United States, this includes a full one-third of all adults and children.
“Significant numbers of the U.S. and the world’s population are overweight,” said Dr. Colditz. “This is another wake-up call. It’s time to take our health and our diets seriously.”