UNDER THE MICROSCOPE:THE HUMAN LONGEVITY record held by Jeanne Calment, who died in 1997 in Arles, France at the age of 122, may now pass to Sakhan Dosova, who claims to have celebrated her 130th birthday on March 27th, 2009. Officially the oldest living person in the world at the moment is Edna Parker, an American who is 114 years old.
Dosova (pictured, right) lives in the village of Prishakhtinsk in central Kazakhstan. The republic of Kazakhstan was part of the USSR but declared itself an independent country in 1991. Although it is possible for someone to live to 130 years of age, claims such as Dosova’s are difficult to substantiate because of doubts about documentation and record-keeping.
Dosova’s remarkable age came to light during a recent census. Demographers then discovered that she was also on Stalin’s first census of the region in 1926, when her age was recorded as 47. Her date of birth is recorded on her old Soviet passport and on her Kazakhstan identity card as March 27th, 1879, the same year that Joseph Stalin and Albert Einstein were born. She was 10 years old when Hitler was born and almost 40 when the Russian Revolution erupted in 1917. Her birth-year of 1879 was also the year Edison unveiled his new invention, the electric light bulb. Dosova has no birth certificate, but such records were not routinely kept in the late 19th century.
Dosova had 10 children, only one of whom, a 76-year-old daughter, is still living. This means that she conceived and gave birth to this daughter when she was 54. She now lives with a granddaughter and seems to be in general good health, if a little hard of hearing. She says she never visited a doctor and never ate sweets. She is very fond of kurt, a local salty dried cottage cheese, and attributes her longevity to a good sense of humour.
ScientificAmerican.com carried an interview on April 1st 2009 with Jay Olshansky, an epidemiologist at the University of Illinois, on the credibility of Dosova’s claim. Olshansky confirms that it is biologically possible for someone to live to be 130, but explains that there is no scientific method to measure biological age reliably.
Sakhan Dosova certainly looks very old in photographs. Olshansky says that skin elasticity is a reliable tell-tale sign of age and points out that the skin of centenarians is translucent. However, the skin of a person who spends a lot of time outdoors tends to age rapidly, so, on this basis you could look much older than you really are.
You might think that telomere length would be an accurate indication of age in humans. Telomeres are bits of DNA that cap the ends of chromosomes and that shorten each time the cell divides. You might think therefore that telomeres would be very short indeed in a very old person. However the whole telomere story is a lot more complicated than that. Cells don’t all divide at the same rate or in the same way and it is not known which cell type would be best for predicting age. It may be that future developments will allow accurate measurements of age to be made from telomere analysis, but this is not possible at the moment.
Mental acuity is another indication of age, but this can vary enormously depending on the individual. Jeanne Calment was very intelligent and alert and could remember things from early childhood.
If Dosha had a daughter when she was 54, this would tend to back up her claims about her own age because many centenarians have children when in their late 40s. People who live to be more than 100 tend to retain a higher level of fecundity much later in life. A reproductively active body protects against ageing.
Claims of extremely long life are often made in this part of Asia. Similar claims made in nearby Georgia some years ago turned out to be unreliable. At that time Georgia was promoting its lifestyle and diet, particularly yogurt, as being especially healthy. Dosova emphasises her liking for cheese, yogurt and ground wheat.
Olshansky is not impressed by the special powers of any diet or special habits such as drinking a glass of wine every day. He mostly attributes exceptional longevity to individual genetics, pointing out that the average life expectancy of 10 generations of Jeanne Calment’s ancestors was in the mid-70s when in that part of France it was mid-30s for everyone else. He also points out that Jeanne Calment smoked and rode a bicycle for more than 100 years!
The best advice to someone who hopes to live for more than 100 years is that they should pick their parents carefully.
William Reville is associate professor of biochemistry and public awareness of
science officer at UCC – http://understandingscience.ucc.ie
