Picture of a guy losing brain cells on White MountainAre the Mountains Killing Your Brain? Alarming new science shows that thin air can wreck brain cells—at lower altitudes than you'd think. Here's how to protect yourself.
"YOU HAVE TO BE poco loco to be a climber," says Dr. Nicholás Fayed. A neuroradiologist at the Clinica Quirón de Zaragoza, in northern Spain, Dr. Fayed leads me into his office and pulls out a collection of MRI images. They're brain scans, taken from amateur and professional mountain climbers after they came back from major expeditions, and the results aren't pretty.
"Atrophy of the frontal lobes," Fayed says, pointing to a black-and-white slice of brain on one MRI. The frontal cortex—the region just behind the forehead that handles higher-level mental functions—looks like a piece of dried fruit. This kind of damage can leave patients with an impaired ability to plan, focus, and make complex decisions. And it's permanent.
SCIENTISTS HAVE long known that the brain can be harmed by extreme conditions such as high-altitude cerebral edema (HACE), in which blood vessels leak fluid into surrounding tissue, causing the brain to swell and press against the skull wall. But Fayed's scans are the first to indicate that brain damage can show up even in people who displayed no symptoms of altitude sickness during their climbs, or had just the usual nausea and lethargy familiar to any hiker in the mountains. And, disturbingly, it seemed to happen to climbers going not much higher than 15,000 feet.
One trekker had cortical atrophy—a permanent loss of gray matter that can cause "spaciness" and other problems—and one had a subcortical lesion, damage to the network of neural pathways in the white matter, which can cause any number of serious issues.
The amateurs on Aconcagua gave themselves six days of acclimatizing for that 9,000-vertical-foot climb (as opposed to the two to three weeks taken by commercial teams), and every brain scan showed problems. (A second scan three years later showed no improvement.) Overall, five of the 23 amateurs
the Spaniards studied had irreversible subcortical lesions—the most serious brain injury the team found. None of the 12 professionals had them.
What is still unclear is how high you have to go, or how fast, before your neurons start dying en masse. The greatest risk lies above 15,000 feet, but there's no reason to assume it can't happen lower.
Protect Your Brain
Follow these steps to prevent high-altitude trouble in your head.
1. Coming from sea level? Spend night one at about 5,000 feet.
2. Ascend as slowly as possible. Medically speaking, the safest rate is
1,000 feet per day above 9,000 feet.
3. Minimize time above 19,500 feet.
4. Climb high, sleep low. The higher elevation will kick-start the
acclimatization process, while descending at night allows the body to adapt
at a safer elevation. Or build in a rest day every 2-3 days.
5. Listen to your body. Never ascend with obvious symptoms of altitude
sickness; descend if symptoms worsen.
6. Stay hydrated, avoid excess salt, and eat foods rich in carbohydrates.
7. Don't drink alcohol—it's dehydrating and depresses breathing.
Thanks to Tom Chester