A recent study tested an existing hypothesis—known as “direct effect”—which suggests that height correlates to cancer risk. The study looked at more than 10,000 cases (male and female) who had contracted cancer, comparing the number of cells in a person (which is bigger in a person who is taller) with other potential variables in taller people which might lead to faster cell division.
While she was not involved with the study, Georgina Hill, of Cancer Research UK, commented, “We’ve known that there is a link between cancer risk and height for quite a long time—the taller someone is, the higher the cancer risk. What we haven’t been sure of is why—whether this is simply because a taller person has more cells in their body, or whether there’s an indirect link, such as something to do with nutrition and childhood.”
She goes on to say that the study does provide some strong evidence which supports the “direct effect” theory, which definitively links the total number of cells in a body to risk for cancer. She notes, “The methodology is good—they took data from larger studies, which is important, and they looked at lots of different categories of cancer.”
Hill also makes a note that cancer risk is also related to lifestyle choices. For example, height only poses a slightly higher risk when compared with making positive life choices like stopping smoking or keeping a healthy weight.
In addition, the study also notes that two types of cancers they tested for—melanoma and thyroid cancer—were found to more vulnerable to the increased risk. The study, then, also needs to consider such things when evaluating cases.
Similarly, Molecular and Clinical Sciences Research Institute (London) director Dorothy C. Bennett notes, “There are no obvious reasons for these exceptions, although the author speculates that cell turnover rates may come into play for melanoma. Bennett was also not involved with the study, but she also explained that pigment cells—which is where melanoma develops—divide and replace faster in taller people. At the same time, referring to this faster cell development rate, Bennett also advises, “I cannot, at present, think of any reason why this should be so, but nor any other clear reason for the higher correlation with height.”