For many Brits, the holiday begins with a pint at the airport pub, a tradition that often continues with in-flight drinks to make the journey more enjoyable. And on long-haul flights, it’s practically an open bar. However, a new study has revealed that combining alcohol with cabin pressure can have serious health implications, especially if you nap after drinking.
The trouble arises when alcohol interacts with the lower atmospheric pressure at cruising altitude, potentially threatening the heart health of passengers. This risk applies even to young, healthy individuals and increases with age or existing medical conditions.
The study, published in the respiratory journal Thorax, found that the combination of sleep and alcohol can lower blood oxygen levels and temporarily raise heart rates. The more alcohol consumed, the greater the impact.
As altitude increases, atmospheric pressure decreases exponentially, causing a drop in blood oxygen saturation to around 90% in healthy passengers at cruising altitude. A further drop below this threshold is known as hypobaric hypoxia, or low blood oxygen level at higher altitude.
Alcohol relaxes blood vessel walls, increasing heart rate during sleep. The researchers wanted to determine if combining alcohol with cabin pressure at cruising altitude could have an additional effect on sleeping passengers.
The study randomly assigned 48 people between 18 and 40 years old into groups based on age, gender, and BMI. Half slept under normal air pressure conditions, while the other half experienced simulated cabin pressure levels at cruising altitude.
In each group, half slept sober for four hours, while the other half slept after consuming alcohol equivalent to two cans of 5% beer or two glasses of 12% wine.
The findings showed that among those who consumed alcohol, deep sleep (the N3 cycle) was significantly reduced to just 46.5 minutes under the combination of alcohol and cruising altitude levels, compared to an average of 67.5 minutes without alcohol.
The researchers concluded that “even in young and healthy individuals, the combination of alcohol intake with sleeping under hypobaric conditions poses a considerable strain on the cardiac system and might lead to exacerbation of symptoms in patients with cardiac or pulmonary diseases.”
They suggest that “practitioners, passengers and crew should be informed about the potential risks, and it may be beneficial to consider altering regulations to restrict the access to alcoholic beverages on board aeroplanes.”
So, while the pre-flight pint may be a beloved tradition, it might be wise to reconsider in-flight drinking, especially if you plan to sleep during the journey, to ensure a restful and healthy flight.