Economy class airline seats don’t cause blood clots, physician group says

By Deborah Kotz, Globe Staff

If you were spending extra for business class seats in an effort to avoid dangerous blood clots while traveling, don’t bother. A new evidence-based guideline from the American College of Chest Physicians finds no proof to support “economy class syndrome” -- yes, it’s an actual term -- an increased risk of deep vein thrombosis due to cramped leg room.

“Traveling in economy class does not increase your risk for developing a blood clot, even during long-distance travel; however, remaining immobile for long periods of time will,” guideline co-author Dr. Mark Crowther of McMaster University in Ontario said in a statement.

Travelers should instead focus on getting a seat on the aisle on long overseas flights, he said, so they can get up and walk around from time to time to reduce the small risk of developing blood clots in their legs.

The guidelines for preventing and treating blood clots, published today in the journal CHEST, reviewed hundreds of studies to outline the best practices for lowering the risks associated with deep vein blood clots in the legs that have the potential to break off and travel to the lungs, causing a potentially fatal pulmonary embolism.

Research suggests that economy class travelers have no greater risk of developing blood clots than those in business or first class.

While the risk of developing blood clots on long-distance flights is very low, the vast majority of those who develop them have certain risk factors:

-- history of previous blood clots

-- cancer diagnosis

-- recent surgery or physical trauma

-- use of oral contraceptives

-- obesity

-- pregnancy

-- age over 65

-- sitting in a window seat

The new guidelines recommend that travelers on flights of six hours or more, who have one of the risk factors, sit in an aisle seat if possible and get up to walk around frequently, say, every hour or so. They can also use compression stockings to keep blood from pooling in their legs.

Those deemed by their physician to be at particularly high risk of blood clots should consider taking a blood thinner like aspirin before the flight, according to the guidelines. But the expert panel recommended against widespread use of aspirin in those who aren’t at high risk because side effects -- such as stomach upset, bruising or ulcers from long-term use -- may outweigh the small protective benefits.

Related: FDA remains concerned about blood clot risks in certain birth control pills

Deborah Kotz can be reached at dkotz@globe.com. Follow her on Twitter @debkotz2.