The interwebs are abuzz over a controversy regarding the ages of several Chinese women gymnasts. Critics point to several news reports, and even an official Chinese government web site, which listed Chinese gymnast He Kexin’s birthday as 1 January 1994 instead of the “official” date of 1 January 1992. That would make her 14 years old and not qualified to compete in the Beijing Olympics.
The problem is that the only official and accepted documents for age — birth certificates and passports — are printed by the very entity that is accused of engaging in fraud. It would be trivially easy for the Chinese government to forge such documents.
Is there another way to ascertain her age? Well, there are age- and development-related changes in hormone levels and other physiological markers. However, these always distribute on a normal curve, and it’s entirely possible for a 16-year-old at the tail end of the distribution to have the developmental and physiological profile of your average 14-year-old. Some girls simply develop more slowly.
(Of course, it’s also possible that the gymnasts’ development was retarded with drugs, which violates IOC rules, and while the IOC is cracking down on other forms of doping, they seem to be turning a blind eye to the possibility of doping for developmental retardation.)
So physiological profiles won’t yield a precise age. Another option is developmental markers such as growth plates in the long bones. Once again, however, the presence of growth plates of a certain size could merely indicate that He is a slow developer. It wouldn’t be proof positive that she is underage. However, the presence of growth plates that indicate a 16-year-old in development would dispel the rumors once and for all.
Another option is amino acid racemization. All amino acids produced in living systems, including humans, are in the L stereochemical configuration. Over time they racemize to the R enantiomer until they reach stereochemical equilibrium, and each amino acid does this at a precise and measurable rate. By comparing the ratio of L and R enantiomers, a time since the deposition of the protein can be determined. One common technique utilizes aspartate racemization. The problem is that the assay must be performed on tissues that are formed at or before birth, and that become essentially biochemically inactive. The most common sources are myelin proteins that line the axons of neurons in the brain, and proteins from certain layers of the lens of the eye. As you might imagine, a biochemical assay of this sort is too invasive to be performed on living subjects.
So there is no good biological aging assay for living human subjects. We are stuck with having to take the word of the Chinese government.
Unfortunately, the Chinese government has a dubious track record on such matters. Chinese gymnast Yang Yun earned a bronze in the Sydney Olympics in 2000, and later admitted that she had been underage during the competition.
Of course, nobody is denying that these gymnasts are talented. He Kexin and her teammates are the best gymnasts at the Beijing Olympics. But if we’re going to have rules, they must be followed. Otherwise, China gains an unfair advantage by being the only team not handicapped by the rules. After all, there may be plenty of 14-year-olds in other countries who are more talented than the gymnasts chosen to represent those countries in Beijing.
Ultimately, this controversy isn’t about gymnastics. It’s about government fraud and government censorship. The damage that could be inflicted on the reputation of the Chinese government, which is working feverishly to orchestrate a positive image of itself during these games, would be far worse than the loss of a few medals. I guess it’s no wonder they are working just as feverishly to cover their tracks.