In the routine of a long distance flight, he alcohol consumption It is a common practice among passengers. The possibility of relax and enjoy a drink During the trip it offers a pleasant and enjoyable experience. However, this practice carries certain risks, especially when combined with particular conditions of the air environment.
The context of alcohol consumption on long flights is influenced by several factors such as the desire to reduce stress, boredom or simply take advantage of the on-board beverage service.
The decrease in partial pressure of oxygen in the airplane cabin, known as hypobaric hypoxia, creates an environment that can significantly affect the passenger’s physiology. In these circumstances, alcohol consumption intensifies the effects of hypoxia, while it can exacerbate the decline in blood oxygen saturation (SpO2) and affect the heart rate.
A study carried out by a team from Institute of Aerospace Medicine of the German Aerospace Center, published in the medical journal Thorax, investigated this combination of factors. By observing how alcohol and hypobaric hypoxia affect sleep, oxygen saturation and heart rate of passengersseeks to better understand the implications of these common practices and provide recommendations to improve the safety and well-being of travelers.
Study participants were exposed to laboratory conditions that mimicked both normal pressure at sea level and the reduced pressure corresponding to 2,438 meters above sea level, which is common in airplane cabins. Under these conditions, their SpO2 levels and heart rate were measured. The groups of participants who were required to consume alcohol ingested an average blood alcohol concentration of 0.043 ± 0.003%, the approximate equivalent of two cans of beer or two glasses of wine.
The results showed a significant drop in SpO2 under the combined exposure of alcohol and hypobaric hypoxia. Median SpO2 during sleep was 85.32% under this combination, compared to 88.07% in hypobaric conditions without alcohol, 94.97% with only alcohol and 95.88% in the sleep laboratory group without alcohol. These data indicate that the alcohol exacerbates hypoxia induced by reduced cabin pressure and leads to increased blood oxygen desaturation.
Furthermore, under the combined exposure, participants spent an average of 201.18 minutes under the clinical hypoxia threshold of 90% SpO2, compared to 173.28 minutes in hypobaric-only conditions and 0 minutes in both sleep laboratory conditions. This finding highlights the risk of prolonged hypoxemia, which can have serious health implicationsespecially in individuals with pre-existing or vulnerable conditions.
Oxygen saturation in healthy people should be between 95% and 100%, according to data provided by the United States Centers for Disease Control and Prevention (CDC). Meanwhile, if it is below 90% it must be a reason for professional consultation.
Regarding heart activity, the study determined that the combined exposure of alcohol and hypobaric hypoxia significantly increased heart rate compared to other conditions. In a normal situation alcohol-free laboratory test, the median Heart rate during sleep was 63.74 beats per minute (bpm). When the participants consumed alcoholheart rate increased to 76.97 bpm. Under hypobaric conditions without alcohol, the heart rate was 72.90 bpm, while under the combination of alcohol and hypobaric hypoxia, the median rose to 87.73 bpm.
This increase in heart rate may be attributed to the combined effects of alcohol and hypoxia on the cardiovascular system, the authors said. Alcohol is a central nervous system depressant that, paradoxically, can increase sympathetic activity, raising heart rate. At the same time, hypobaric hypoxia imposes an additional burden on the cardiovascular system, since the body tries to compensate for the lower availability of oxygen by increasing the heart rate to maintain adequate tissue oxygenation.
The significant increase in heart rate observed under the combination of these factors suggests that alcohol consumption during long-haul flights may impose an additional burden on the heart, especially in an already stressful environment such as the airplane cabin.
According to information from Maya Clinic, “the heart of adults at rest usually beats between 60 and 100 times per minute,” but “a low heart rate is not always a problem. For example, a resting heart rate between 40 and 60 beats per minute is quite common during sleep and in some people, particularly healthy young adults and trained athletes.”
Sleep is divided into several stages, including light sleep (N1 and N2), deep sleep (N3)and the REM sleep (rapid eye movement). Deep sleep is particularly important for physical and mental restoration, as it is the phase in which the body repairs tissues, builds bones and muscles, and strengthens the immune system.
The results of the study showed that the combination of alcohol and hypobaric hypoxia had a notable impact on reducing deep sleep. Under these combined conditions, participants experienced a significant reduction in time spent in the N3 phase, with a median of 46.50 minutes.
In comparison, time in deep sleep was 84.00 minutes under the alcohol-only condition and 67.50 minutes in the no-alcohol condition in the sleep laboratory. These data suggest that the combination of alcohol and hypoxia not only affects the amount of deep sleep, but drastically reduces it, which could compromise the recovery and overall well-being of passengers.
Additionally, reduced deep sleep is associated with a decrease in overall sleep quality, which can lead to a number of problems, such as fatigue, lower cognitive performance and increased irritability. Passengers who fail to achieve sufficient periods of deep sleep may feel less rested and more likely to experience jet lag symptoms and other sleep-related disorders.
The study authors cautioned that, in light of this research, “even in young and healthy individualsthe combination of alcohol intake with sleep in hypobaric conditions represents a considerable strain on the cardiac system and could cause an exacerbation of symptoms in patients with heart or lung disease.”
Additionally, “higher doses of alcohol could amplify these observed effects, potentially increasing the risk of health complications and medical emergencies during the flight, especially among older people and those with pre-existing medical conditions,” they noted. “Our findings strongly suggest that should be restricted the consumption of alcoholic beverages on board,” they said.