Here’s proof it's better to be shorter

Short? You have a smaller risk for blood clots.
Short? You have a smaller risk for blood clots.

If you are short, you may have to leap over puddles that normal people step over, but at least you will have the last laugh.

There may be at least one advantage to being short: a lower risk for dangerous blood clots in the veins, a new study shows.

A previous Health24 article also stated that added height and weight contributed to the risk of blood clots.

Smaller risk for deep vein thrombosis

These clots, called venous thromboembolisms, include blockages known as deep vein thrombosis (DVT), which typically start in the legs and can travel to the lungs, raising a person's odds for stroke.

Sometimes DVTs occur after long-haul flights, so they've been dubbed "economy class syndrome". But new research suggests a slight advantage for shorter people in avoiding the clots.

Why the effect? "It could just be that because taller individuals have longer leg veins there is more surface area where problems can occur," theorised study lead author Dr Bengt Zoller.

"There is also more gravitational pressure in leg veins of taller persons that can increase the risk of blood flow slowing or temporarily stopping," noted Zoller, an associate professor at Lund University and Malmö University Hospital, in Sweden.

Connection between height and blood clots

According to the American Heart Association, up to 600 000 people in the United States develop a blood clot that starts in a vein each year. Risk factors for these clots include having surgery, cancer and being immobilised or hospitalised. Pregnancy or taking hormonal oral birth control pills or oestrogen therapy for menopause can also cause blood clots.

According to the Southern African Journal of HIV Medicine, over 200 000 South Africans suffer from DVT each year, and because most DVT is not obvious, the true incidence is unknown.

Although the new study can't prove a cause-and-effect link, one US heart expert said other recent research has also suggested a connection between height and clots in veins.

"As we can't do much about our height, it is worthwhile considering some preventative action" in shielding taller folks against these clots, said Dr Maja Zaric. She's a cardiologist at Lenox Hill Hospital in New York City.

"Wearing gradual support stockings along with avoidance of dehydration and increasing walking during 'periods of risk' [such as prolonged sitting] may help prevent the problem before it occurs," Zaric said.

Lower risk for shorter people

The new study involved more than 2.6 million people from Sweden: male soldiers whose health was tracked from the 1950s to the 1990s, and newly pregnant women tracked from 1969 to 2010.

The entire study group consisted of sibling pairs, to tease out any genetic or environmental factors, the researchers explained.

Zoller's team found that men shorter than 1.6m were 65% less likely than men 1.8m or taller to develop one of these clots.

The risk dropped 69% for women shorter than 1.5m who were pregnant for the first time, compared to women 1.8m or taller, Zoller's team reported on 5 September in Circulation: Cardiovascular Genetics.

Of course, "height is not something we can do anything about," Zoller said in a journal news release. And he noted that "the height in the population has increased, and continues increasing, which could be contributing to the fact that the incidence of thrombosis has increased."

Study limitations

The study does have some limitations. The researchers said they weren't able to consider lifestyle factors from the participants' childhood, such as diet, physical activity and whether or not their parents smoked. But they believe their findings could possibly apply to the US population, because the current Swedish population is now similarly ethnically diverse.

It is unclear how ethnic diversity in South Africa affects the prevalence of blood clots.

And Zaric agreed that a link between height and clotting seems plausible.

"This can be explained by the simple mechanics of a large and long blood vessel being exposed to the higher gravitational force which is exerted on the 'longer' blood column," she said. This could cause blood to flow less well, "which in turn may trigger development of a clot in the leg veins," Zaric said.

Image credit: iStock

We live in a world where facts and fiction get blurred
In times of uncertainty you need journalism you can trust. For 14 free days, you can have access to a world of in-depth analyses, investigative journalism, top opinions and a range of features. Journalism strengthens democracy. Invest in the future today. Thereafter you will be billed R75 per month. You can cancel anytime and if you cancel within 14 days you won't be billed. 
Subscribe to News24
Show Comments ()
Editorial feedback and complaints

Contact the public editor with feedback for our journalists, complaints, queries or suggestions about articles on News24.