The Hidden Health Risk of Alcohol Consumption While Flying According to Science : ScienceAlert

If you’re considering enjoying some alcoholic beverages on your next long flight followed by a little shuteye, you may want to reconsider. New research indicates that this common practice could be placing additional stress on your heart.

A study conducted by the Institute of Aerospace Medicine at the German Aerospace Center involved 40 volunteers in two separate sleep lab chambers. One chamber simulated normal ground level pressure, while the other recreated the pressure experienced in an airplane cabin flying at 2,438 meters (approximately 8,000 feet).

It’s already understood that at higher altitudes, where oxygen levels are reduced, blood oxygen saturation (SpO₂) can decline—a condition called hypobaric hypoxia. According to this fresh study, mixing alcohol and sleep in such conditions can create a risky scenario.

“For the first time, this study investigates the combined effects of hypobaric hypoxia and alcohol consumption during sleep,” the researchers explain in their report.

“Our findings highlight that the onboard consumption of alcohol is an underappreciated health risk that could be easily avoided.”

Participants were grouped based on whether they were sleeping under normal or cabin pressure and whether they consumed alcohol. The given alcohol amount was roughly equivalent to two cans of beer or two glasses of wine. Sleep was capped at four hours, similar to typical on-flight sleep disruption.

The results showed that individuals at normal pressure who drank had an average blood oxygen level of 94.97 percent and a heart rate of 76.97 bpm. In comparison, non-drinkers at normal pressure had 95.88 percent SpO₂ and 63.74 bpm. For those at lower cabin pressure, drinkers registered 85.32 percent SpO₂ and 87.73 bpm, while non-drinkers had 88.07 percent SpO₂ and 72.90 bpm.

The study indicates that cabin pressure conditions naturally reduce blood oxygen and increase heart rate, but these effects are exacerbated when alcohol is in the mix.

With an SpO₂ below 90 percent considered unhealthy, combined with a heightened heart rate, concern arises over the cardiovascular strain caused by common flying habits, particularly for those with pre-existing heart problems.

While the study’s sample was small and comprised of young, healthy adults, the effects could be more severe in older or less healthy individuals, warranting further investigation.

Despite the appeal of relaxing with a drink and some sleep, especially while vacationing or after a business trip, the study’s authors advocate for increased traveler awareness.

“This issue should be brought to public attention through patient groups, public awareness campaigns, and health advice provided by airlines,” the researchers suggest. “Due to technical and financial limitations, it is improbable that airlines will enhance cabin pressure settings.”

The research can be found in the Thorax journal.

What does hypobaric hypoxia mean?

Hypobaric hypoxia is a condition that occurs when the body is exposed to low oxygen levels at high altitudes, which can happen in environments with lower atmospheric pressure such as in an aircraft cabin.

What blood oxygen level (SpO₂) is considered healthy?

A healthy clinical norm for SpO₂ is at or above 90 percent. Levels below this may indicate that the body is not receiving enough oxygen.

Can drinking alcohol while flying affect sleep quality?

According to the study, the combination of alcohol consumption and lower cabin pressure can decrease the amount of time spent in deep and REM sleep, both critical for high-quality sleep.

Should people with pre-existing heart conditions avoid alcohol on flights?

The study suggests that those with existing heart conditions should be particularly cautious about consuming alcohol on flights due to the increased cardiovascular strain caused by lower oxygen levels and higher heart rates.

Is it likely that airlines will change cabin pressure settings to be safer for consumption of alcohol?

The study indicates it is unlikely that airlines will adjust cabin pressure settings due to technical and financial constraints, hence it is up to passengers to make safer health choices while flying.