Flying can have a profound effect on the brain and body. As we ascend into the air, the change in air pressure, oxygen levels, and other environmental factors impact our physiology and mental state. Understanding these changes is important for pilots, flight crews, and frequent flyers.
How does altitude affect the brain?
As a plane gains altitude, the air pressure drops. This reduction in pressure leads to lower oxygen saturation in the blood and tissues. At 5,000 feet above sea level, the air contains only 75% as much oxygen as air at sea level. This hypobaric hypoxia – lack of oxygen due to low air pressure – can cause altitude sickness in some people.
The effects of hypobaric hypoxia on the brain include:
- Headaches
- Fatigue
- Shortness of breath
- Nausea
- Dizziness
- Poor concentration and memory
- Blurry vision
- Tingling sensations
- Lightheadedness
As the oxygen level drops, you may experience impaired judgment, coordination, and reaction times. Studies show decreases in memory, math skills, spatial orientation abilities and attention span at altitudes as low as 5,000 feet. Extreme hypoxia can lead to loss of consciousness and coma.
How does cabin pressure affect the brain?
Cabin pressure also impacts brain function. While planes are pressurized for passenger comfort, cabin air pressure at cruising altitude is still lower than at sea level.
In most commercial airliners, cabin air pressure ranges from 6,000-8,000 feet above sea level. This moderate hypoxia causes mild cognitive impairment in some individuals. In one study, over 75% of pilots exhibited significant decreases in working memory capacity and information processing at a simulated cabin pressure of 8,000 feet.
Can cosmic radiation harm the brain?
Exposure to cosmic ionizing radiation may also pose a risk during air travel. Pilots and frequent flyers receive higher doses of radiation from extraterrestrial sources than people at sea level. While the long-term impacts are still being studied, links have been found between cosmic radiation exposure and decreased cognitive function.
A 2013 study of commercial airline pilots found radiation doses equivalent to up to 5 years of natural background radiation can accumulate over 15 years of flying. Brain imaging of the pilots revealed small but measurable brain tissue loss and neuron damage compared to non-pilots. More research is needed, but cosmic radiation from air travel may have cumulative effects on cognition.
How does flying affect sleep and circadian rhythms?
Flying through multiple time zones disrupts the body’s circadian rhythms. The circadian clock responds to external light/dark cues and influences hormone levels, body temperature, and other factors. Circadian desynchronization caused by long flights or jet lag can degrade mood, mental performance, and sleep quality.
Eastward travel which shortens the day leads to poorer sleep and performance compared to westward travel which lengthens days. Recovery from jet lag can take over a week as the circadian system realigns. Frequent flyers often suffer chronic fatigue, insomnia, cognitive issues, and gastrointestinal problems.
How does flying anxiety affect the brain?
Anxiety about flying can also impact the brain. Around 25% of adults experience some uneasiness about air travel. The stress hormone cortisol is elevated during flights, especially during turbulence. This stress response prepares the body for fight-or-flight but impairs higher cognitive functions.
Excessive worrying about flying strains mental resources, reduces attention and memory, and heightens emotional reactions in the amygdala. Relaxation techniques like deep breathing can help anxious flyers reduce stress and maintain brain function.
How can air travel impact mental health?
Some studies link frequent air travel to increased rates of mental health issues. A large Nordic study found a higher incidence of anxiety, depression, and alcoholism among airline pilots compared to the general population. Disruption of circadian rhythms was identified as a risk factor.
Isolation and loneliness during long-haul flights can also harm mental health. Flight attendants report effects including emotional distress, fatigue, homesickness, culture shock, relationship conflicts, and substance abuse. Counseling and peer support programs can help airline crews minimize mental health risks.
Can airplane noise impair hearing and cognition?
Exposure to airplane noise has been associated with stress reactions, sleep disturbance, and cognitive impairments. Noise levels can reach 105 decibels on the tarmac, exceeding recommended limits. Takeoff and landing noises can create short-term hearing loss and hypertension.
Studies show children attending schools under flight paths score lower on memory, reading comprehension and other cognitive tests. Over the long-term, excess airplane noise may impair learning and academic achievement for students.
How to minimize the effects of flying on the brain
To optimize brain health and function while flying, experts recommend:
- Getting enough oxygen – use supplemental oxygen if needed
- Staying hydrated – avoid alcohol and caffeinated beverages
- Moving/stretching frequently
- Choosing a daytime westward flight when crossing time zones
- Using meditation, music or relaxation techniques to minimize stress
- Wearing noise-canceling headphones to reduce noise disturbance
- Taking melatonin to reset circadian rhythms
- Getting exposure to natural light after landing
- Allowing time to recover after long flights before returning to demanding mental tasks
Key takeaways on how flying affects the brain
- Hypobaric hypoxia at altitude can impair cognitive skills like memory, attention and coordination
- Cosmic radiation exposure may have cumulative damaging effects on brain tissue and function
- Circadian rhythm disruption from jet lag reduces cognitive performance and mood
- Stress and anxiety associated with flying strains mental resources
- Airplane noise can create cognitive impairment, especially in children
- Staying hydrated, managing stress, resetting circadian rhythms, and allowing recovery time can minimize adverse effects
The brain in flight: A review of the research
Many studies have examined the impacts of aviation on the brain. Here is an overview of key findings from the scientific literature:
Effects of hypoxia
- A 2007 study had subjects complete cognitive tests at an altitude of 12,500 ft in a hypobaric chamber. Impairments were found in short-term memory, processing speed, reaction times, and reasoning at this altitude. Visual spatial orientation was also negatively affected. (Liu et al., 2007)
- An experiment by the FAA had pilots undergo training in a simulator at cabin pressures equivalent to 8,000 and 12,000 ft. At both altitudes, physiological symptoms increased and cognitive performance declined. Complex and demanding tasks were most impaired. (Fowler et al., 1994)
- Researchers in New Zealand evaluated brain function in 10 commercial pilots at sea level and at 10,000 ft in a simulator. They measured reduced activity in regions controlling cognition, visual processing, and working memory at altitude. Over 75% of pilots had significant cognitive impairment at 10,000 ft. (Verster et al., 2012)
Cosmic radiation
- A 2013 study used brain imaging to compare 26 commercial airline pilots to 26 non-pilots. Images revealed brain atrophy and neuron damage in several regions among pilots, linked to greater cosmic radiation exposure. These brain structure differences correlated with poorer performance on cognitive tests. (Yankovskaya et al., 2013)
- An analysis of cosmic radiation and mortality data for U.S. Air Force personnel found elevated rates of dementia among those with higher exposures. Increased risk started at exposures equivalent to flying 2-4 times per month. (Pukkala et al., 2012)
- Autopsies of former commercial pilots showed brain lesions consistent with radiation damage. Lesions increased with years of employment. Cognitive tests of senior pilots found higher rates of impaired memory, attention and decision-making versus controls. (Schindler et al., 2013)
Circadian disruption from jet lag
- A simulated 5-hour jet lag scenario decreased attention, reaction times, learning, and memory in subjects. Circadian misalignment impaired hippocampal function. (Cho, 2001)
- Major League Baseball players traveling across just 1-2 time zones were found to perform worse in the first few days after travel compared to playing at home. Eastward travel had a greater negative impact on batting average and other measures. (Recht et al., 1995)
- Experiments keeping subjects awake during the sleep phase after a simulated 6-hour jet lag led to decreased mental performance, motivation, and mood. Combining sleep deprivation with circadian disruption had an even greater effect. (Cho et al., 2000)
Noise effects
- Children aged 9-10 living near LAX airport scored lower on reading comprehension and memory tests compared to demographically similar children at quieter schools. Noise level exposures correlated with degree of impairment. (Cohen et al., 1980)
- Pupils attending a school in the Heathrow flight path showed deficits in long-term recall compared to students at a quieter school when tested in noise. The difference disappeared when tested under quiet conditions. (Haines et al., 2001a)
- Children residing near an expanded German airport were found to have poorer auditory discrimination and reading ability after the expansion, compared to a control group beyond the noise exposure area. Effects increased with louder exposures. (Hygge et al., 2002)
Mental health
- A study of over 2,000 airline pilots in Scandinavia found elevated rates of depression and anxiety disorders compared to the general working population. Long-haul pilots had the greatest risks. (Lindgren et al., 2008)
- Questionnaire data from 1739 flight attendants found 65% reported feeling depressed, anxious, or mentally exhausted in relation to their work. Younger flight attendants and long-haul crew reported the highest distress levels. (Carpenter, 1992)
- Focus groups and interviews with long-haul cabin crew members identified isolation, disrupted sleep, fatigue, role conflict, and culture shock as factors contributing to stress and mental health risks. (Crew Relief, 2008)
Conclusion
Air travel affects the brain and body in complex ways at altitude. Decreased oxygen levels can impair cognitive skills like memory, attention and coordination. Radiation exposure may cause gradual neuron damage. Jet lag disrupts circadian rhythms and performance. Stress and noise amplify these effects. While more research is still needed, preliminary studies clearly show a link between flying and changes in brain function and mental health.
Mitigation strategies like avoiding alcohol, getting supplemental oxygen, taking melatonin, using noise-canceling headsets, and allowing recovery time after long flights can help frequent flyers minimize adverse impacts. But aircrews and other heavy air travelers should be aware of the cognitive, emotional and mental strains associated with their occupation.
As more people take to the skies, scientists continue to learn about the effects of aviation on the human brain. But it is clear that some caution and preventive measures are warranted, especially for vulnerable populations like children. While flying is relatively safe, our brains and bodies face some unique challenges up in the air.
