Why Air Journey Can Take a Larger Toll on the Brain Than We Notice

Deborah Kan is an award-winning journalist and founding father of Being Patient. In this “Thought of the Week” column every Friday, she highlights one of many key tales shaping the way forward for mind science.

Dear readers.

I spent final week in Hong Kong, however after I landed in San Francisco, I used to be overcome with a splitting headache. I’ve flown to Asia and again extra instances than I can rely however questioned why flying provides me a nasty headache on some flights however not others.  

I did a little bit of analysis and found that the cabin you’re sitting in isn’t pressurized to sea stage. It’s pressurized to the equal of 6,000 to eight,000 ft above sea stage (in regards to the top of Machu Picchu.) That means each passenger on a long-haul flight is spending 14 hours in circumstances just like the bottom camps of high-altitude mountaineers. And one a part of the mind takes the toughest hit.

The area of the mind most affected by flying is the prefrontal cortex. Attention, studying, verbal talents, and government operate all decline to variable levels with ascent to altitude. Past research documented this with handwriting samples, which turned extra jumbled as altitude elevated. The prefrontal cortex is the final a part of the mind to develop in adolescence. It seems to be among the many first to register the consequences of diminished oxygen. 

Cabin air humidity can drop to 10 to twenty p.c, in comparison with 30 to 60 p.c on the bottom. The mind is sort of 75 p.c water, and even delicate dehydration measurably impairs cognitive operate. Alcohol makes it worse. At altitude, the physique absorbs alcohol quicker than it does at sea stage, which suggests one drink at 37,000 ft is extra like two on the bottom!

A neuroimaging study revealed in Human Brain Mapping discovered that useful exercise was considerably diminished within the hippocampus following long-haul flights crossing a number of time zones. The hippocampus is the a part of the mind the place reminiscences are made and saved. Researchers from UC Berkeley discovered that jet lag instantly reduces the start of latest neurons within the hippocampus. And the consequences don’t resolve shortly. Cognitive operate was impaired not simply throughout jet lag however for as much as a month afterward!

For frequent long-haul flyers, the image turns into extra regarding. Studies on flight attendants who skilled repeated jet lag with restricted restoration time between flights confirmed diminished temporal lobe quantity and spatial studying deficits in comparison with floor crew. These cognitive deficits had been long-lasting, extending for a number of years, and had been related to elevated ranges of cortisol, the stress hormone. Cortisol, when chronically elevated, is particularly disruptive to hippocampal operate. 

So, headache defined! I went down a rabbit gap, however there’s sufficient analysis to grasp the following time I fly lengthy haul, hydration and sleep are one of the best methods to make a full restoration.

With hope,
Deborah