By almost any measure, tall men are winners of the genetic jackpot. They’re perceived as more desirable by potential partners and earn more money than their shorter peers. But height is no advantage when it comes to the risk of deadly blood clots.
In a study from the University of Tromso in Norway (where they know about tall — the average Norwegian male stands 5 ft. 11.5 in., compared with the average 5-ft.-10-in. American male), researchers looked at height and weight data for nearly 27,000 people and compared it to their rate of venous thromboembolism over 12.5 years.
Venous thromboembolism causes blood clots to form in the deep veins, usually in the legs, a condition known as deep vein thrombosis. If the blood clot breaks away and travels to the lung, it is called pulmonary embolism, which can block blood supply, kill lung tissue and cause death.
(More on TIME.com: “What’s a Pulmonary Embolism?”)
The study found that both height and obesity increased men’s risk of clotting. Tall men (6 ft. or taller) were 2.6 times more likely to develop venous thromboembolism than short men (5 ft. 8 in. or shorter). Obese, short men were at 2.1 times greater risk than slim, short men. And men who were both tall and obese were five times as likely to develop the condition as their shorter, thinner peers.
Women didn’t get off the hook either: Obese, taller women (5 ft. 6 in. or taller) were nearly three times more likely to develop blood clots than petite (5 ft. 3 in. or smaller), lean women.
(More on Time.com: “What’s the Ideal BMI for Longevity?”)
It’s not clear exactly why height increases the risk of venous thromboembolism, but the researchers suggest it has something to do with the circulatory system. “In tall people the blood must be pumped a longer distance by the calf-muscle pump, which may cause reduced flow in the legs and thereby raise the risk of clotting,” lead researcher Sigrid Braekkan said in a statement.
In addition, obesity causes increased pressure in the abdomen, which may further reduce the ability of the calf-muscle pump to return the blood from the legs. Also, Braekkan says, obesity is linked to a state of constant low-grade inflammation, which could make blood more susceptible to clotting.
(More on Time.com: “Want to Sharpen Your Mind? Drop a Few Pounds”)
It’s just one more reason to watch your weight: there’s nothing you can do about your height, but your weight is largely under your control.