A new study out of University of California Riverside claims that tall people have a higher risk of developing cancer – and the reason is simply more cells. Leonard Nunney, a professor of biology at UC Riverside, looked at data from large-scale surveillance projects with his research team to test the hypothesis that the increased cancer risk for tall people was simply due to the fact that they have more cells in their bodies.
Nunney said in a paper detailing his research, published in Proceedings of the Royal Society B, that a person’s risk of developing cancer increases by 10% for every 4 inches they are over average height. The average height of those being looked at in the study was 5-foot-4 for women, and 5-foot-9 for men. A link was found between total cell number and the likelihood of developing cancer in 18 of the 23 cancers the study looked at. The study also found that taller women had a higher risk than taller men. Taller women were 12% more likely to develop cancer, while men were 9% more likely.
This is not the first time that it’s been suggested that tall people have a higher cancer risk. But the questions Nunney’s research aimed to answer was, is that risk due to a larger amount of cells or some other lifestyle factor?
Georgina Hill from Cancer Research UK told CNN that Nunney’s research provides good evidence that the “direct effect” theory, or the idea that the amount of cells a person has is directly related to their risk of developing cancer, is likely, because the research looked at data from large studies, and looked at several different categories of cancer.
Hill did say, however, that it’s “only a slighter higher risk and … there are more important actions that people can take to make positive changes [to decrease their cancer risk], like stopping smoking and maintaining a healthy weight.”
It’s also worth noting that the study found unexpected results in certain areas. While research indicated that there’s a link between cell number and cancer risk in 18 of the 23 cancers looked at, thyroid cancer and melanoma showed unexpectedly high correlation with height, leading researchers to believe some other factor was to blame for the increased risk.
“Data for the majority of cancers are consistent with the direct-effect hypothesis that the effect of height on cancer risk is due to increased cell number,” Nunney wrote in his paper. “However, the data for melanoma, and perhaps for skin cancer in general, show a relationship to height that is too strong to be explained solely by cell number changes.”
So while the “direct-effect” seems to hold weight when it comes to height and cancer risk in several cancers, more research still needs to be done. And, as Hill stated, the increased cancer risk is only slightly higher.