Health News

Put Food in Your Belly Before Boarding

Nov. 21, 2000 -- Sky-flying holiday travelers, take note. It's not wise to board an airplane without a little something in your stomach. A new study suggests that dehydration may cause in-flight medical emergencies -- anything from passing out to a heart attack -- and grabbing a quick snack and nonalcoholic drink before boarding could offset the risk.

"Dehydration may be part of the problem," lead author Makoto Matsumura, MD, a researcher at the Saitama Medical School in Japan, tells WebMD. He presented his results at the American Heart Association meeting in New Orleans.

But other researchers say that the stress of air travel -- and people not taking heart medications correctly while on the road -- also likely contribute to these medical emergencies.

Such emergencies occur more often than most people think -- at a rate of one person per 800 to 1,900 flights, Matsumura says. Fainting and heart attacks account for more than half of the emergencies.

His theory: Low cabin pressure at a higher altitude causes blood vessels throughout the body to expand as the body attempts to increase its oxygen supply. For many people, the result is a headache or feeling cold or tired, and no treatment is necessary. But why would it spur a heart attack or fainting in some people?

Dehydration is known to cause low blood pressure, which could put people at risk, Matsumura says. Coupled with the low cabin pressure, dehydration could cause more serious problems. His study was designed to test this theory and evaluate the need for food and fluids to prevent such emergencies.

Twelve healthy volunteers ranging in age from 22 to 42 fasted for 12 hours before beginning the study, which took place in a controlled-pressure training lab used by Japan's Air Force pilots. The study itself simulated a typical -- albeit short -- 25-minute flight, including takeoff and landing.

Before the "flight," all the volunteers had decreased blood pressure and decreased oxygen levels in the blood vessels of the legs, arms, and brain. However, after eating a light snack and having a drink, eight volunteers had improved oxygen levels in their brains and other organs.

Because dehydration could be the primary problem, Matsumura says, drinking something is most important. "We think that [about 16 ounces] of soda is enough," he tells WebMD. However, he cautions, eating "too much is not good because it may induce heart failure in people who have heart disease."

Eating too much before you board -- like that big Thanksgiving dinner -- also can be a big risk for a different reason, Michael Lauer, MD, director of clinical research in cardiology at the Cleveland Clinic in Ohio, tells WebMD. "I've always worried about encouraging people to have a lot on their stomachs when they get on board an airplane because of the risk of vomiting."