March 29, 2011
Genes For Fast High Altitude Adjustment
The US military is funding research to predict who will get sick when suddenly transported to high altitude locations (e.g. by parachuting onto a mountain). The latest round of research will try to verify an earlier round that identified 6 genetic variants that appear to predict who will do worse at high altitude.
Robert Roach, who directs the Altitude Research Center at the University of Colorado, performed a similar test last year, taking 28 research subjects to a simulated altitude of 16,000 feet by putting them in a special chamber that mimics the effect of a low-oxygen environment. A blood test, screening for those six genetic elements, was able to predict with 96% accuracy which of the 28 would fall ill.
The researchers hope their research will ultimately lead to the development of drugs that cause human metabolisms to adapt to high altitudes. But drug development typically takes many years and many hundreds of millions of dollars. Not all drug development efforts succeed and many drugs on the market have side effects that one should avoid risking unless absolutely necessary.
Since drug development is a distant prospect genetic testing to select rapid adapters would seem a more practical way to the knowledge garnered from this research. If genetic testing can predict which soldiers have the best prospects to hit the ground running (and shooting) then for high altitude jobs why not just send the soldiers whose genetic profiles indicate they can handle it?
Some groups (e.g. Tibetans) carry genetic variants that adapt them especially well to high altitude living. Once those genetic variants are identified those genetic variants are probably rare outside of groups that have lived at high altitudes for many centuries. But gene therapies, cell therapies, and tissue engineering techniques will provide ways to basically do software upgrades.
Adjustment to altitude is just one of many types of genetically determined capabilities that will get genetically screened for in the future. Where it will get especially interesting: offspring genetic engineering. This isn't just about muscles, beauty, and intelligence. As this report above demonstrates, many other genetic adaptations are possible. So will parents choose genes optimized for high or low altitude living? For cold or warm or moderate temperature? For low tendency for distraction to allow more sustained abstract reasoning or for higher tendency for distraction to be more responsive to other people or to dangers?
The real question is, how long will it be before we have a decent approximation of the tradeoffs involved? (What are the costs of these "high altitude genes"? I suspect I won't want my kids to have them.)
These genes don't really seem to be for fast adjustment, just for a slightly greater tolerance to the thin air of the heights to begin with. Notice that in the article they show a chart that indicates what percentage of regular people will get altitude sickness if suddenly transported to various altitudes, and once you get to 15,000 feet it's basically everybody. So, although this is indeed cool research, I think that the military's main strategy (as well as that of anyone else who wants to visit high altitudes) will have to continue to center around acclimatization. If it's really that important to be able to airdrop soldiers at 13,000 feet on short notice, they'll want to have some guys who are living at or near that altitude all of the time.
Interesting stuff. I love how the military can bet cutting edge yet totally bungle the basics. For instance, the military will put 130 lb men in infantry positions with 90 lbs of gear to carry around, with little history of weight & strength training to prepare his body for the stress of a huge weight increase on the body. (Discussed in this link, a strength training blog I read - http://www.70sbig.com/blog/2011/02/the-wrong-strategy/ )
Not to mention women.
What might happen? Genetic testing, if implemented like every other measure, might be used to restrict people from professions for which they'd otherwise qualify 95% of the time. Imagine that say, 5% of paratrooper missions would require mountain breathers. There's a good chance that the military, as a bureaucracy with dumb rules that cater to the lowest common denominator, and leave no room for discretion, would simply bar non-mountain breathers from becoming paratroopers, meaning an otherwise lower quality paratrooper - just as if Harvard required everyone to be 6'5" or taller, their student quality would suffer.
Any wagers that the drugs that would allow faster adaptation will also improve atheletic performance, and end up illegal?
Which in and of itself is a travesty, Phillep. Why should I lose access to a miracle of science because its use threatens the statistics of some entertainers?
China is also working hard on the problem. They are overflying Tibet with their new J-11 fighters. Our response could be a function of planners considering "fighting on the roof of the world."
Chinese troops operating at the highest altitudes (4,500 meters, on the Indian border) now have access to exercise rooms (one of 1,000 square meters and another of 3,000 square meters) that are supplied with an oxygen enriched atmosphere. Troops exercising in these rooms increase the oxygen in the blood, and are much less likely to get hit with a case of altitude sickness. Thus the troops can stay in shape without getting sick. For border patrols at high altitudes, troops usually carry oxygen bottles and breathing masks. China also has a serious problem in Tibet with altitude sickness among its troops. This illness occurs when people who grew up near sea level (most of the world's population) move to altitudes greater than 2,100 meters (7,000 feet). Below that, the air contains 21 percent oxygen. Above that, the weaker air pressure lowers the amount of oxygen the body can absorb. That produces "altitude sickness", manifested by shortness of breath, disorientation, nosebleeds, nausea, dehydration, difficulty sleeping and eating, headaches and, if you stay up there long enough, chronic disability.
The average altitude of Tibet is 4,100 meters (14,000 feet). Most people can adapt, sort of, to the altitude sickness. Some can't. But the Tibetans have evolved to deal with it. The majority of Chinese soldiers coming to the Tibetan highlands (which is most of Tibet) require a few days, or weeks, to acclimate. But they are still susceptible to altitude sickness if they exert themselves, especially for extended periods. This makes Chinese military personnel in Tibet much less effective.