Height has been linked to a range of health problems, from Alzheimer's and heart disease to multiple cancers. How stature stacks the odds of getting sick is unclear, but experts say the link between height and health offers new hope for understanding puzzling diseases.
Here are five common conditions linked to height.
A new study suggests taller women have heightened risk for ovarian cancer, a disease that kills nearly 15,000 American women each year, according to the U.S. Centers for Disease Control and Prevention.
British researchers reviewed data from 47 studies involving more than 100,000 women. For every 5-centimeter (2-inch) increase in height above the average 5 feet 3, the risk of ovarian cancer rose 7 percent, according to the study published Tuesday in the journal PLoS Medicine.
In July 2011, a study published in the Lancet Oncology found taller women had an increased risk of 10 different cancers, including breast and skin cancer. And taller men have an increased risk of prostate cancer, according to a 2008 study published in the journal Cancer Epidemiology, Biomarkers & Prevention.
"One of the big surprises in cancer has been the potential impact of early life nutritional factors on long-term cancer risk," said Dr. Tim Byers, a professor of preventive medicine and biometrics at the University of Colorado Cancer Center in Denver. "I think height is an indicator of some risk factor, but we don't know what the mechanism is."
The findings offer little comfort for tall men and women, whose height -- guided by genes, nutrition and other environmental influences -- was established in their 20s. But Byers said taller people should not worry any more, nor should shorter people worry any less, about their cancer risk.
"Whether you're tall or short, staying away from tobacco, being physically active, eating a balanced diet and maintaining a healthy are beneficial behaviors for everyone," he said. "And get the recommended cancer screening tests, regardless of height."
Heart disease is the leading cause of death in the U.S., killing 616,000 people per year, according to the CDC. And unlike cancer, it seems to affect shorter people more than their taller counterparts.
A recent review of 52 studies involving more than 3 million men and women found shorter people have a 50 percent higher risk of having deadly heart disease than tall people.
"It would be interesting to explore the possibility that short stature is connected with the risk of [coronary heart disease] and [heart attack] through the effect of smaller coronary artery diameter, and that smaller coronary arteries may be occluded earlier in life under similar risk conditions," the authors wrote in their 2010 report published in the European Heart Journal.
A 2006 study published in the American Journal of Epidemiology found identical twins who died from coronary heart disease tended to be shorter than their co-twins, suggesting the height-heart disease link stems from environmental factors that affect both height and heart disease risk rather than genetics.
"If there is some environmental factor acting early in life that both affects adult height and somehow programs us for certain diseases, we need to look early in life for those factors. It's not impossible, but it's hard," said Byers, explaining the difficulty of asking adults to accurately recall what they ate as children. "It would be nice if everyone kept a diary, wouldn't it?"
Like heart disease, serious strokes are also more common among shorter people.
An Israeli study of more than 10,000 men, 364 of whom died from stroke, linked each 5-centimeter (2-inch) increase in height with a 13 percent increase in fatal stroke risk. Men who were in the shortest quartile had a 54 percent higher risk of fatal stroke than men in the tallest quartile, according to the 2002 study published in the journal Stroke.
"Height might represent a strong indicator of nutritional status, especially in a study such as ours, which included many subjects who had lived as persecuted minorities in their childhood," the authors wrote. "It could also be associated with environmental conditions in childhood and adolescence."
While nutrition is known to influence height, Byers height may also influence hormones to dictate disease risk.
"I suspect that height is probably an indicator of early life nutritional factors that somehow play out 50, 60 years later. But the other possibility is that taller people have slightly different hormone profiles than shorter people," he said. "This definitely needs more attention."
Alzheimer's disease is the most common cause of dementia in older people, affecting 5.4 million Americans, according to the Alzheimer's Association. The risk increases with age and a family history of Alzheimer's, highlighting the disease's genetic roots. And according to a 2007 study, the risk is also higher for shorter people.
The study, which compared 239 Alzheimer's patients with 341 healthy controls, found men who were taller than 5 feet 10 inches had a 59 percent lower risk of developing the disease than men who were shorter than 5 feet 6 inches. The study was published in the Journal of Alzheimer's Disease.
Cardiovascular disease, which is more common among shorter people, is also linked to an increased risk of Alzheimer's disease. It's unclear whether all three are linked.
While type 2 diabetes is linked to weight, type 1 diabetes -- also called juvenile diabetes -- may be linked to height.
"Taller children generally seem to experience increased risk for development of diabetes mellitus type 1, except perhaps during infancy or early adolescence," according to a 2002 study published in the journal Pediatrics.
The cause of type 1 diabetes is unknown, but it's thought result from an autoimmune attack on the insulin-producing cells of the pancreas. Although it can occur at any age, it's usually diagnosed in children, teens or young adults.
There is debate surrounding the link between height and diabetes, however, as other studies have suggested children with diabetes are similar in stature or even shorter than their non-diabetic peers.
While diabetes, Alzheimer's, cardiovascular disease and cancer are distinctly different health problems, their relationship to height could signal some common underlying mechanism.
"It's possible, but we just don't know," said Byers. "It's a kick in the head to us researchers to remind us to answer some of these fundamental questions."