Shark lives up to 500 years may hold key anti-aging secrets

By Stephen Beech via SWNS

A rare shark species that lives for up to 500 years could hold key anti-aging secrets to extend human lifespans, suggests a new study.

Experimental research shows that muscle metabolic activity may be an important factor in the incredible longevity of the Greenland shark, the world’s longest-living vertebrate species.

The findings may have applications for conservation of the vulnerable species against climate change - or even for human cardiovascular health, say scientists.

Greenland sharks (Somniosus microcephalus) are the longest living vertebrate with an expected lifespan of at least 270 years and possibly beyond 500 years.

Lead researcher Ewan Camplisson said: “We want to understand what adaptations they have that allow them to live so long."

It was previously thought that their long lifespan was due to the sharks' cold environment and minimal movement.

But the factors behind the species extreme longevity appear to be far more complex, prompting researchers to investigate alternative theories.

Camplisson, a PhD student at the University of Manchester, said: “Most species show variation in their metabolism when they age.

“We want to determine if Greenland sharks also show this traditional sign of aging or if their metabolism remains unaltered over time.”

To measure the metabolism of the sharks, Camplisson and his team conducted enzyme tests on preserved muscle tissue samples from Greenland sharks.

They measured the metabolic activity of the enzymes with a spectrophotometer across several different shark ages and environmental temperatures.

The team found no significant variation in muscle metabolic activity across different ages, suggesting that the metabolism does not appear to decrease over time and may play a key role in their longevity.

Camplisson said: “This is quite different to most animals which tend to show some variation in their metabolic enzyme activity as they age.

“The results support our hypothesis that the Greenland shark does not show the same traditional signs of aging as other animals.”

The findings also show that the Greenland shark's metabolic enzymes were "significantly" more active at higher temperatures.

Camplisson said: “This would suggest that the shark’s red muscle metabolism is not specially adapted for the polar environment, otherwise we would have expected to see less of a temperature related difference in activity."

The researchers warned that in a world with a rapidly changing climate, long-lived species that are less able to adapt may be the most at risk of extinction.

Camplisson said: “A female Greenland shark may not become sexually mature until it is 150-years-old and with such a long generation time, the species will have far less of a chance to adapt to anthropogenic changes in their environment."

Now he plans to test more enzymes and tissue types to gain an even deeper understanding of the shark’s metabolic activity.

Camplisson said: “My ultimate goal is to protect the species and the best way to do this is to better understand them."

He is also interested in the possible applications of the findings for the understanding of human heart disease.

Camplisson added: “By studying the Greenland shark and its heart, we may be able to better understand our own cardiovascular health.

“These are issues that become progressively more common and severe with increasing age.”

The findings were presented at the Society for Experimental Biology annual conference in Prague, Czech Republic.