Does being tall make you more likely to get cancer? Research suggests that it might. The research examined connections between height and cancer among Swedish adults, and found that for each additional 10 cm (a little less than 4 inches), the risk of cancer increased by 10-30 percent, varying by type of cancer. As strange as it sounds, there may be a genuine correlation. What does previous research say?
This study turns out to be one of many that have found a positive link between increased height and cancer risk. For example, a 1997 study of male doctors found a small increase in overall cancer, and specifically prostate and colon cancers, among taller physicians. The risk of other cancers, such as lung cancer, did not definitely increase with patient height. In the doctor study, perhaps even more fascinating are the insights that the study provides into the habits of tall doctors; taller doctors tended to both exercise and drink more than their shorter colleagues.
Why would such a link exist? A 1998 study in BMJ by D.J.Gunnell and colleagues is one of the first to examine possible causes, doing more than just confirming the existence of a height-cancer association. Gunnell looked closely at pre-puberty growth, specifically leg length. Legs grow the most before puberty, and thus long legs are a better proxy for hormone exposure than adult height, which is more closely connected to nutrition. At this point, the logic gets a little murky. Gunnell notes that the link between height and cancer is strongest in breast and prostate cancers, which are known to be influenced by sex hormones. Therefore, those who undergo puberty early are exposed to higher concentrations of sex hormones for a longer period, increasing cancer risk. The problem is that while Gunnell notes a connection between height and puberty, and between puberty and rapid growth, there is no evidence presented of a link between the effects of early puberty and adult height.
While hormones may be involved in the link between cancer and height, there might be a simpler explanation. Increased height and body size are also associated with larger organs. The taller doctors, for example, have larger colons and prostates. Larger organs have more cells in them, and since cancer is a disease of cells, more cells mean more risk. The current study found that the incidence of melanoma increased the most with greater height; that may happen simply because taller people have more skin, so more skin cells and more surface area exposed to the sun. The bottom line is that taller people may have slightly elevated risks of some cancers, but don’t worry. As risk factors go, height is minor. That said, sunscreen is always a good idea.