Bodywork: Are larger people more prone to cancer?
Here’s a question from a reader:
I’ve been told that cancer occurs when the process of cell division goes wrong. I would assume that larger people have more cells. Does that make them more prone to cancer?
— Tim Hassen
Dr. Prescott prescribes
The taller you are, the more cells you have. (Interestingly, once we reach adulthood, gaining or losing fat or muscle doesn’t appear to change the number of cells we have; instead, it seems only to alter the size of those cells already in our bodies.)
With more cells, it would make sense that tall people would be at greater risk for cancer, as there would be a greater chance for things to go wrong. But just because something seems to make sense doesn’t make it true; that’s why scientists conduct experiments.
In a study published last year, a biologist from the University of California, Riverside, looked at this very question.
Analyzing data gathered from hundreds of thousands of cancer patients, he concluded that taller people do, indeed, have a greater risk for cancer. Generally, this risk grew by about 10 percent for every four inches of added height.
Statistics have long shown that men have higher rates of cancer than women. The study found that men’s heights (about six inches taller on average) contributed substantially to those differences between the sexes.
This height effect, though, was not uniform for all forms of cancer. In melanoma, a skin cancer, risk shot up dramatically for tall people. (It’s probably not because they have more skin cells; the likely culprit is higher levels of a circulating growth hormone that accelerates cell division, especially in skin cells.)
Meanwhile, other cancers showed little or no correlation to height, with short and tall people displaying similar rates of pancreatic, esophageal, stomach and oral cancers. This suggests that environmental factors are driving cancer rates in these forms of the disease, irrespective of cell numbers.
Across all cancers, the height effect was relatively small. If you’re a man of average height — 5-foot-9 or so — your lifetime risk of developing some form of cancer is about 38 percent. For your 6-foot-1 buddy, those chances grow to 42 percent.
While interesting, these findings are not something even Steven Adams should be fretting about. We can’t alter the number of cells we have.
We can, however, make adjustments to our lifestyles. And those changes — eating right, moderating alcohol intake, wearing sunscreen, avoiding tobacco — can have dramatic effects on cancer risk.
Prescott, a physician and medical researcher, is president of the Oklahoma Medical Research Foundation. Cohen is a marathoner and OMRF’s senior vice president and general counsel.