Even in the scientific landscape of 2023, the battle against cancer continues to perplex researchers worldwide. However, hidden within the animal kingdom lies a remarkable creature that has ingeniously cracked the code.
Referred to as the animal that “lives two lifetimes” by the Inuit people, the bowhead whale has a lifespan that can span an incredible 200 years (1). But wait, it also weighs over 80 tonnes; the bowhead whale claims its rightful place as the second heaviest mammal on our planet, right after the blue whale (2). The bowhead whale’s tale of longevity and immense size is truly a sight to behold.
To understand just how exceptional an ability is to escape from cancer, we must first find out how cancer is formed. DNA damage is the main culprit. We experience DNA damage on a daily basis from sources such as the radiation in our environment. Luckily, our bodies have the amazing ability to detect that damaged DNA and avoid them from turning into cancer. Tumor suppressors are responsible for those checks.
But why do we still get cancer? When the gene in our DNA responsible for producing these tumor suppressors gets damaged, no one is left to check anymore. Those cells with damaged DNA will seek this opportunity to divide uncontrollably, turning into tumors. Fortunately for us, humans have 5 different tumor suppressors, so cancer is still a rare occurrence (3).
Bowhead whales are much larger than us, having many more cells. Surely that means they would have a higher chance of having cancer? Is it because they have even more tumor suppressors? Well, not quite. When a cancerous cell gets detected in our bodies, its typical fate would be inevitable death. Induced cell death, or apoptosis, will kill off these cancer cells and stop them from dividing further (3). Senescence could also happen, which means the cell stops dividing and dies slowly rather than being killed immediately. Both of these processes contribute to ageing. Some cells are not replaced when they die, such as our heart cells. As DNA damage accumulates, more and more cells are dying, and our bodies experience this through ageing (3). In bowhead whales, cancerous cells are not killed but saved. They have a highly functioning DNA repair system involving two proteins that repair DNA damage to avoid killing their cells (1). The same repair proteins are also in us humans but at a much lower concentration, meaning that we cannot repair our DNA to the same amazing standard as the bowhead whales can (1).
Through this well-established system, bowhead whales are not only avoiding cancer but also slowing down the process of ageing. They owe their incredible longevity to their surprisingly efficient DNA repair system. Now, the only question left is whether us humans could also utilize their secrets.
Scientists think that the reason the Bowhead whales developed such a system is due to the fact that they live in the freezing Arctic waters (1). Under unique and extreme environmental challenges, animals can evolve the most amazing abilities to adapt to them. The ultracold temperature triggers the production of repair proteins, so they are present in massive numbers in Bowhead whales. It is still unclear the exact mechanism behind this mysterious process, but similar effects are already in use in humans. Cryotherapies are used in sports communities to reduce the long-lasting effects of injuries and calm inflammations (4). Therapeutic hypothermia has also been used in patients after a cardiac arrest to promote healing in the heart tissue (4). More studies need to be done, but it’s hopeful that in the near future, we could fully uncover the secret behind cancer and ageing, all with the help from our friends in the deep, cold ocean.
Why not embrace the ice cold and take a deep dive into an icy lake? In northern parts of Europe and the arctic circle, people have believed that cold swims and submersions can promote health for a very long time(4), and the bowhead whales have shown us that this claim is indeed backed by science. Speaking of which, I’m about to have a nice long cold shower while thinking about all the benefits it would bring, bye for now!
References:
1. Firsanov D, Zacher M, Tian X, Zhao Y, George JC, Sformo TL, et al. DNA repair and anti-cancer mechanisms in the longest-living mammal: the bowhead whale. bioRxiv. 2023;
2. George JC, Bockstoce JR. Two historical weapon fragments as an aid to estimating the longevity and movements of bowhead whales. Polar Biol. 2008;31(6).
3. Williams GH, Stoeber K. The cell cycle and cancer. Vol. 226, Journal of Pathology. 2012.
4. Kwiecien SY, McHugh MP. The cold truth: the role of cryotherapy in the treatment of injury and recovery from exercise. Vol. 121, European Journal of Applied Physiology. 2021.
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