Aging is a very interesting topic. The “process of becoming old” is so complex that, at the moment, there are hundreds of theories on why and how we age. Scientists are trying to understand this process in order to slow it down or even possibly reverse it. To do so, many researchers are now looking at the animal kingdom. Specifically, at the longest living animals on earth. Understanding their biological processes can teach us a lot about how aging works - and maybe help us live a longer and healthier life.
So let’s have a look at the longest living animals - and what we can learn from them.
Naked mole rats (Heterocephalus glaber) may not be the prettiest animals but they definitely have unique characteristics. Originally from eastern Africa, these little wrinkly pink and sometimes translucent rodents are extremely long-lived compared to their relatives. They can in fact live up to 50 years, decades more than other rodents. An unexpected number, considering that smaller mammals tend to have a shorter lifespan.
One of their unique characteristics is that naked mole rats are usually resistant to cancer, dementia and neurological decline. Scientists discovered something very interesting. Naked mole rats' healthy cells can turn into cancerous cells. But an unusual HA molecule, involved in sticking cells together, stops the initial stages of cancer from developing into tumours. Scientists are studying these animals, wondering if they could actually lead us to a cure for cancer.
Another unique feature is that naked mole rats, together with blind mole rats, are the only cold blooded mammals. Many species with a lower basal body temperature have a longer and healthier life. In a nutshell, a low body temperature could extend longevity. Affecting metabolic rates, it decreases the rate of biochemical reactions and retards the processes that cause ageing. We still need some research to find how we could apply this insight to humans.
Elephants are not only the biggest animals on land, but also the longest-living mammals on land. Asian elephants (Elephas maximus), in particular, can live for up to 86 years. It’s about the same life expectancy of humans. As humans, they also have a complex neocortex and demonstrate a wide variety of behaviors associated with high intelligence: compassion, grief, altruism and self-awareness.
One of the main reasons why scientists are studying elephants is because of their high resistance to cancer. In fact, bigger animals are statistically more likely to get cancer. But it’s not the case for elephants. The reason can be found in a tumor-suppressing gene called P53. Humans have one copy. Elephants have 20. This gene can recognize damaged DNA, try to repair the cells linked to it and, if it doesn’t work, can decide to kill them. Almost like an internal doctor.
Researchers hope that, by studying this animal’s cancer defenses, they may find some ways to identify cancer at its initial phases and treat it.
Bowhead whales (Balaena mysticetus) are the longest living mammals on earth. They can in fact live up to 200 years. They spend their entire lives in the arctic seas and can reach up to 20 meters length and 91.000 kg.
Since they live in extremely cold waters, their body temperature and metabolic rate are lower compared to most mammals. As we said before, low body temperatures are often a biomarker of longer lifespan and healthy aging. Through the study of bowhead whales’ genome, scientists found one specific gene involved in body temperature regulation that may in fact explain such a long lifespan.
Additionally, like naked mole rats, bowhead whales don’t get cancer. How do they do that? Put simply, cancer occurs when the body’s cells divide and mutate too rapidly. Most of the time, mutations are either harmless or the body is able to fix them. But when it doesn't, that can lead to cancer. Since Bowhead whales are so big and live for so long, they should be more likely to get cancer. But some genetic mutations in the part of their genome controlling cell cycle, cell proliferation and DNA repair stops their cells from getting cancer. Understanding which exact genome mutation allows it may help us prevent cancer in humans.
Greenland sharks (Somniosus microcephalus) are among the world’s largest predatory sharks, growing up to more than 5 meters in length. Furthermore, they have unique genes that allow them to live up to 500 years, making them the longest-living vertebrate known.
Unfortunately, we still don’t know how Greenland sharks are capable of living for centuries. The fact that they live in the Arctic Ocean, at about 2.000 meters depth, where the water temperature is very low, helps them have a slow metabolism and maturation. Greenland sharks don’t reach adulthood and can’t reproduce, until they are 150 years old.
Their hearts are also very interesting for scientists. Our hearts beat once every second. Greenland sharks' hearts beat instead only once every 12 seconds. And they can keep beating, without any cardiovascular diseases, for up to 500 years. By studying the pathways which prevent their heart from changing form and function with age, researchers may develop drugs which mimic this process in humans. And maybe find a way to help people with cardiovascular diseases live a healthier and longer life.
Finally, there is an animal that can biologically live forever - a very tiny 4.5 mm jellyfish. It lives in temperate to tropical waters all around the world and, because of its unique quality, it’s called Immortal Jellyfish (Turritopsis dohrnii). Potentially, if there weren’t predators, they would never die of old age.
How is this possible? Let’s first understand the jellyfish life cycle. Jellyfish typically start their lives as fluctuating larvae. Once reaching the seafloor, they attach to it and turn into polyps. These ploys feed and grow until they detach and start fluctuating again in the form of ephyra larvae. These larvae finally develop into jellyfish. Mature immortal jellyfish can reverse their life cycle when in danger or starving. They can go back to their polyps phase. And they can do this over and over.
Behind this reversing skill there is a cellular mechanism, a rare process known as transdifferentiation. Scientists are studying this mechanism, in order to potentially apply it to human medicine. An adult cell is specialized for a particular tissue. But by undergoing transdifferentiation, this same cell can become an entirely different specialized cell. It’s an efficient way of cell recycling and an important area of study in stem cell research that could help scientists replace cells damaged by diseases.
In the last centuries, a human’s life expectancy has been constantly increasing. And nature has helped us increase it in many ways. For example, the accidental discovery of penicillin thanks to a specific mold. Now it is the most widely used antibiotic in the world, saving thousands of lives every year.
We expect that, by looking at and learning from the animal kingdom, we will be able to find ways to treat several illnesses and extend human longevity.
While we hope these discoveries will give results in the near future, there is a chance they may take some time. Illnesses like cancer are still often incurable. But we think that people alive today should have a chance to receive treatments that will maybe be available only in the future. By choosing Cryonics, you will be able to give yourself a chance to be treated one day. Our standby teams will stop your body’s biological processes and degradation after your legal death. Doing so, once the illnesses that caused your death will be treatable, you will be cured and finally revived. Ready to live a healthy extended life.
If you want to know more about this possibility, give us a call!
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