By Stephen Beach, via SWNS
A rare shark species that can live for up to 500 years may hold important anti-ageing secrets that could help extend human lifespan, according to a new study.
Experimental studies suggest that metabolic activity of muscles may be a key factor in the extraordinary longevity of the Greenland shark, the world’s longest-lived vertebrate.
The findings could have applications in protecting vulnerable species against climate change and even in human cardiovascular health, the scientists say.
The Greenland shark (Somniosus microcephalus) is the longest-lived vertebrate animal, with an estimated lifespan of at least 270 years and possibly more than 500 years.
“We want to understand what adaptations they have that enable them to live such long lives,” said lead researcher Euan Camplison.
Until now, it was thought that the reason for sharks’ long lifespan was the cold environments they live in and the fact that they move very little.
But the factors behind this species’ extreme longevity appear to be much more complicated, leading researchers to investigate alternative theories.
“Most species show changes in their metabolism as they age,” said Camplison, a doctoral student at the University of Manchester.
“We want to determine whether Greenland sharks also show these traditional signs of ageing, or whether their metabolism remains unchanged over time.”
To measure the sharks’ metabolism, Camplison and his team performed enzyme tests on samples of preserved muscle tissue from Greenland sharks.
The researchers used a spectrophotometer to measure the metabolic activity of enzymes in sharks of different ages and environmental temperatures.
The team found that metabolic activity in muscle did not change significantly with age, suggesting that metabolism does not decline over time and may play an important role in longevity.
“This is quite different from most animals, who tend to show some changes in metabolic enzyme activity as they age,” Camplison said.
“These results support our hypothesis that Greenland sharks do not show the same signs of aging as other animals.”
The study also shows that metabolic enzymes in Greenland sharks become “significantly” more active at higher temperatures.
“This suggests that the metabolism of sharks’ red muscle is not specifically adapted to polar environments, otherwise we would expect temperature-related differences in activity to be less significant,” Camplison said.
The researchers warned that in a world with a rapidly changing climate, long-lived species that are less able to adapt may be most at risk of extinction.
“Female Greenland sharks may not reach sexual maturity until they are 150 years old, and the long generation period means this species will have much less opportunity to adapt to human-induced changes in its environment,” Camplison said.
He now plans to test more enzymes and tissue types to gain a deeper understanding of the sharks’ metabolic activity.
“My ultimate goal is to conserve this species, and the best way to do that is to understand it better,” Camplison said.
He’s also interested in whether the findings can be applied to understanding heart disease in humans.
Camplison added: “By studying Greenland sharks and their hearts, we may be able to better understand our own cardiovascular health.”
“These are problems that become increasingly common and severe as we age.”
