How tall people are is linked with how they might die, with taller people more likely to die from cancers, and shorter people more likely to die from heart problems or stroke, according to new research.
Researchers reviewed 130 studies that collected information on nearly 1.1 million people's heights, along with their causes of death. In studying the trends in the data, the researchers found links between people's heights and their likelihoods of dying in different ways.
"In the early days of insurance, [companies] looked at height as an indication of survival," said David Batty, an epidemiology and public health researcher at the University College London, who was not involved in the study. The association between height and mortality cause has long been established, but the review is one of the largest conducted on the topic.
"It's not discovery science, it is confirmation," Batty said.
Childhood predicts height
The study participants were born between 1900 and1960. Eighty-five percent were white, and 93 percent lived in North America or Europe. The researchers accounted for the fact that people have generally grown taller over time, with an average height increase of 0.27 inches every five years.
The average height of men in the study was 5 feet 8 inches; the average height of women was 5 feet 3 inches.
The reason height is linked with certain causes of death is that height can be a sign of the sum of the health conditions a person experienced during childhood, Batty said. Height is also partly determined by genetics, Batty noted, though how tall a person actually grows does not always reflect their maximum possible height.
"Height tells you about early life predictors — social circumstances, nutrition, genetic inheritance — height captures all those things," Batty said.
A shorter stature can be a sign of malnourishment, chronic infection or chronic diarrhea. It can also be the result of a stressful childhood, Batty said, such as having parents who go through a painful divorce. This certainly isn't to say that all short people experienced such events while growing up; the trend only becomes apparent when large numbers of people are considered.
Still, factors that affect development during childhood can predict health through adulthood, Batty said. This is partly because socioeconomic class in childhood is a strong indicator of socioeconomic class in adulthood.
The fact that taller people are more likely to be hired for jobs also has an effect, he said. The success associated with height may partly explain why shorter people are more likely to die from mental health disorders, Batty said.
How height affects mortality
Evidence suggests that taller people are more likely to be leaner, exercise more and smoke less, Batty added. These differences in health behaviors may lead taller people to generally have better cholesterol levels and lower blood pressure, which may explain why shorter people are more likely to die of heart disease, heart attack or stroke.
One reason that taller people are more likely to die of many types of cancer is because they tend to have bigger organs, so there is a greater chance that one cell in the organ will become cancerous, Batty said.
Batty emphasized that the data show correlations in mortality causes in the general population, but should not be applied to individual cases.
"None of the mechanisms are direct," he said, adding that the research has little impact on clinical practice. A person's height is not something a doctor can advise they change, as opposed to how a doctor can advise against smoking cigarettes, Batty said.
The study was published online July 23 in the International Journal of Epidemiology.
Pass it on: Taller people are more likely to die of cancer, while shorter people are more likely to die of heart disease.