Cancer More Likely In Tall People

A recent study published in The Lancet this month adds to a growing body of evidence that suggests tall people are more likely to develop cancer than their shorter counterparts.

The study, led by British researchers at the Cancer Epidemiology Unit, University of Oxford, involved almost 1.3 million women who were followed for an average of 9.4 years.

Over the course of the study 97,376 cases of cancer occurred. The researchers found that the risk of cancer increased by 16% for every 10cm increase in height. Women in the tallest group, who measured at least 175cm, were 37% more likely to develop cancer at a given age than women in the shortest group, who measured less than 155cm.

Cancer sites that showed the strongest increases included kidney cancer (29% increase in risk per 10cm), colon cancer (25%), rectal cancer (14%), melanoma (32%), breast cancer (17%), endometrial cancer (19%), ovarian cancer (17%), leukaemia (26%), non-Hodgkin lymphoma (21%), and cancers of the central nervous system (20%).

Graph Of Cancer Incidence And Height

On the other hand, cancers of the mouth and pharynx, oesophagus, stomach, lung, and pancreas appeared to be unlinked with height. The association between height and cancer appeared stronger in non-smokers than smokers (19% increase per 10cm vs 11% increase), probably because many of the smoking related cancers were not strongly linked to height.

The researchers concluded that the increasing rates of cancer observed during the 20th century could be explained, at least in part, by changes in adult height over the period – the average adult height increased by around 10cm between 1900 and 2000.

This study backs up findings of similar studies in men. One such study, published in the journal Cancer Causes & Control in 1997 found that men taller than 73 inches were 21% more likely to develop cancer than those who were shorter than 67 inches.

The increased risk of cancer in tall people is believed to be due to either a greater caloric intake, a larger total number of cells in the body, or increased levels of insulin-like growth factors. A greater caloric intake is believed to increase cancer risk by increasing the production of cancer causing free radicals in the body. The total number of cells in the body is important simply because the more cells a person has, the more opportunities exist for one of those cells to become cancerous. Insulin-like growth factors are proteins that play an important part in human growth however they have been shown to stimulate the growth of certain forms of cancer such as breast and prostate cancer.

Despite the increased risk of cancer, tall people tend to have a slightly increased life expectancy than shorter people. A 2003 study of 386,627 Korean men found that age adjusted mortality decreased by 3% for each 5cm increase in height. A Finnish study published in 1999 found that a 5cm increase in height lowered the risk of death by 9% and 10% in men and women respectively. These findings appear to be due to a significantly lower risk of dying from heart disease and respiratory illnesses such as chronic obstructive pulmonary disease (COPD) that outweighs the increased cancer risk.