For every extra 10 cm in height from the median, the chance of getting cancer increases by 11% for men and 18% for women. The link was reported by Swedish researchers at the European Society for Paediatric Endocrinology meeting in Barcelona, Spain. While other studies have reported this link, this was the largest yet performed involving 5.5 million Swedish men and women ranging in height from 1 meter (3.3 ft) to 2.25 meters (7.4 ft).
The researchers led by Dr Emelie Benyi, from the Karolinska Institute in Sweden, analyzed health data pertaining to millions of Swedes born between 1938 and 1991. Not all cancers appeared under the same incidence with height. For instance, for every extra 10 cm the risk of developing skin cancer increased by 30% and breast cancer increased by 20% in women.
“It should be emphasised that our results reflect cancer incidence on a population level. As the cause of cancer is multifactorial, it is difficult to predict what impact our results have on cancer risk at the individual level,” Benyi said.
No steps were taken to limit confounding factors like smoking, age, education, access to healthcare and so on. Given the huge sample size, however, the link seems very strong and should not be taken lightly even though researchers have yet to identify a causal relationship. Despite it's no clear what might cause taller people to get cancer more often than short people, researchers have some clues. One plausible explanation might be related to growth hormones, seeing how people with genetic dwarfism rarely get cancer. Studies on mice which were genetically altered to express more or less growth hormones found that cancer incidence increased or decreased accordingly.
“Our studies show that taller individuals are more likely to develop cancer but it is unclear so far if they also have a higher risk of dying from cancer or have an increased mortality overall,” said Dr Benyi.
“In general, I would caution against interpreting a link as causal – however for height and cancer there is considerable evidence that suggests that the link is not explained by other known factors. Clearly, adult height is not itself a ‘cause’ of cancer, but is thought to be a marker for other factors related to childhood growth," said Dr Jane Green, clinical epidemiologist at the University of Oxford, for The Guardian.
“To put risk associated with a non-modifiable factor like height in context, it is worth noting that taller people have lower risks for heart disease and a lower risk of death overall.”