Expert reveal why drinking wine on flights causes blood oxygen levels to drop

Many passengers view a glass of red wine as a convenient remedy for falling asleep during long-distance flights. However, recent medical insights suggest that this common practice poses significant risks to health and sleep quality.

Taking to Instagram on Tuesday, Dr Kunal Sood, a Maryland-based physician specialising in anesthesiology, shared evidence that consuming alcohol before napping in a cabin environment leads to a measurable drop in blood oxygen levels and an increased heart rate.

Cardiovascular and respiratory strain

The air within a plane contains less oxygen than typical ground-level air. Dr Sood explains that drinking alcohol before sleeping further impairs the body's ability to maintain stable oxygen saturation.

This phenomenon is particularly concerning for individuals with pre-existing heart or lung conditions, as the combined effects of alcohol and altitude put them at a higher risk of medical complications.

The illusion of sleep quality

While alcohol may help passengers fall asleep faster, it functions poorly as a sleep aid. Dr Vassily Eliopoulos, a longevity expert, notes that alcohol suppresses REM sleep and slow-wave deep sleep—the vital stages where the brain consolidates memory and regulates cortisol.

Even two drinks can reduce sleep quality by up to 24 percent. This disruption prevents the brain from clearing metabolic waste, ultimately leading to elevated stress hormones and accelerated cellular ageing.

Rather than arriving refreshed, passengers who use alcohol to sleep often experience heightened physiological stress.