'Survival' genes helped Russians endure the Leningrad siege: Blood samples reveal DNA mutations slowed down metabolism

  • Researchers took blood samples from 206 survivors of the Leningrad siege
  • They analysed the structure of the genes involved in metabolism
  • Survivors were almost a third more likely than the control group to have gene variants that slow down metabolism and use energy economically 

For 872 days from the start of the harsh cold Russian winter of 1941, three million people were subjected to food shortages and freezing temperatures during the siege of Leningrad.

A reported 1.5 million people starved to death, but an almost equal amount of the city's residents survived, leading scientists to wonder what it was about these survivors that set them apart.

And now analysis of blood samples has revealed those who were able to endure the blockade may have been saved by a genetic mutation that helped their bodies use energy more efficiently.

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Researchers  took blood samples from 206 survivors of the Leningrad siege (residents pictured). They analysed the structure of the genes involved in metabolism and discovered survivors were a third more likely than a control group to have gene variants which help their bodies use energy more efficiently

Researchers took blood samples from 206 survivors of the Leningrad siege (residents pictured). They analysed the structure of the genes involved in metabolism and discovered survivors were a third more likely than a control group to have gene variants which help their bodies use energy more efficiently

The samples were taken from 206 survivors of the Leningrad siege, now known as Saint Petersburg, by researchers from Ott Research Institute of Obstetrics and Gynecology in Russia. 

In particular they used a technique known as polymerase chain reaction (PCR) to target and replicate genes involved with regulation of metabolism in white blood cells. 

The groups also repeated the process of 139 people of similar ages who lived in Russia but were not involved in the siege. 

They found the survivors were 30 per cent more likely than members of the control group to have variants associated with slowing down metabolism.

Specifically, these variants were found in an uncoupling protein known as UCP3, which affects how efficient cells are at using energy. 

Mutations were also spotted in two peroxisome proliferator-activated receptors - PPAR alpha and PPAR delta - both involved with regulating muscle metabolism.

Specifically, these variants were found in an uncoupling protein known as UCP3, which affects how efficient cells are at using energy. Mutations were also spotted in two peroxisome proliferator-activated receptors - PPAR alpha (illustrated) and PPAR delta - both involved with regulating muscle metabolism

On 8 September 1941, German troops surrounded Leningrad - modern-day Saint Petersburg (marked) - and blockaded the city. More than 3 million residents were trapped and food supplies were cut. The siege lasted 872 days and as many as 1.5 million people reportedly starved to death or were killed by the cold

THE SIEGE OF LENINGRAD 

On 8 September 1941, German troops surrounded Leningrad - modern-day Saint Petersburg - and blockaded the city. 

More than 3 million residents were trapped and food supplies were cut. 

On 12 September, authorities estimated that the city had enough flour to last just 35 days, cereals for 30 days, meat for 33 days and sugar for 60. 

By the end of the first month, oil and coal supplies ran out causing water pipes to freeze, effectively shutting off water supplies.  

By November, rations were said to have been as low as one third of the daily recommended amount for adults and reports suggest animals, including rats and crows as well as family pets, were used as food. 

In some cases bread rations were limited to just 0.2lbs (125g), people were getting just 200 calories a day, and 100,000 people were dying a month. There were even reports of cannibalism. 

The siege lasted 872 days and as many as 1.5 million people reportedly starved to death.

People with these genetic variations may be able to take energy from food to conserve and use it more effectively than those without.

This means that those with the genes during the Leningrad siege were able to manage the energy they got from food rations more efficiently, and keep their bodies warm. 

'Genetic predisposition alongside with other factors was that very sieve which those siege survivors had to pass and managed to survive in that demanding environment,' lead researcher Professor Oleg Glotov told Russia Today

'Those genes did not emerge by chance, in other words, those people already had them [and] about 20 to 30 percent of the population has those markers.'

He added the mutation is an advantage in harsh conditions, but could be a disadvantage in areas of plentiful food and warmer climates for example.

However, Professor Glotov is quick to highlight the sample size is small in comparison to the number of those who survived the siege.

And as people age and die, the potential sample size is decreasing. 

He plans to continue the research and develop a larger 'biobank' at the Saint Petersburg University and believes the results may also prove helpful when tackling obesity, anorexia and metabolism disorders.

The study is published in the Russian journal Advances in Gerontology and detailed in Science.  

People with these gene variations are able to take energy from food and conserve and use it  in harsh conditions more effectively than those without. This means that those with the genes during the Leningrad siege (pictured) were able to manage energy they got from rations more efficiently and keep their bodies warm

People with these gene variations are able to take energy from food and conserve and use it  in harsh conditions more effectively than those without. This means that those with the genes during the Leningrad siege (pictured) were able to manage energy they got from rations more efficiently and keep their bodies warm

 

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