- A new research review shows a strong link between being overweight or obese and 13 types of cancer, The New York Times reports.
- Excess fat was already known to raise the risk of adenocarcinoma of the esophagus, colorectal cancer, breast cancer in postmenopausal women, and uterine and kidney cancers.
- The new review — conducted by a working group of WHO’s International Agency for Research on Cancer and published in the New England Journal of Medicine — also found solid evidence tying obesity to gastric cardia, liver cancer, gallbladder cancer, pancreatic cancer, thyroid cancer, ovarian cancer, meningioma, and multiple myeloma.
Combined, these 13 cancers are responsible for close to half (42%) of all new cancer diagnoses.
“Only smoking comes close” as an environmental risk factor for cancer, said Graham Colditz, working group chairman and a professor of medicine and surgery at Washington University in St. Louis, according to the Times.
The studies were mostly observational, comparing overweight adults with adults whose body mass index was in the normal range of 18.5 to 24.9. For certain cancers, the group found that risk increased with the heavier a person became. For example, a woman with a BMI of 25.29.9 was at 50% greater risk for endometrial cancer than one with a normal BMI. That risk doubled when BMIs reached 30 to 34.9 and was seven-fold higher at a BMI or 40 or more.
The results should be a wake-up call for women. Both postmenopausal breast cancer and uterine cancer showed strong connections to fat — the latter having the greatest association of all 13 cancers.
There was also some evidence suggesting a link between obesity and male breast cancer, diffuse large B-cell lymphoma and the most common form of non-Hodgkin’s lymphoma, according to the review.