Regeneration and rejuvenation

Superheroes and supervillains such as Deadpool, Wolverine and Sabretooth from the Marvel X-men series have superpowers of regeneration, allowing them to heal quickly, recover from deadly wounds, or even regrow whole body parts. Such characters are practically immortal, as they can survive any injury and restore their bodies to perfect working condition. 

Normal humans such as ourselves can also recover from some injuries, like cuts or broken bones. People have even been known to regenerate their fingertips after accidents, and our liver can regrow itself to its original size even after 75% has been lost, e.g. due to surgery or injury. However, some of the most important organs in our body, such as the heart and brain, only have a very limited ability to regenerate, and we cannot regrow entire limbs. 

This means that our bodies cannot fully recover from some diseases and injuries. For example, a heart attack can cause 25% of the cells in the left ventricle of our heart to die. As the heart cannot fully repair itself from such a large injury, it becomes scarred. Similarly, neurodegenerative diseases such as Alzheimer’s disease, Parkinson’s disease and amyotrophic lateral sclerosis (ALS) are caused by neurons and glial cells dying, which the body cannot replace. These diseases cause lasting damage to our organs, and as a result our bodies become less fit and healthy with age.

In contrast to humans, some animals have real superpowers of regeneration. The axolotl, a type of salamander, can regenerate whole limbs, as well as its eyes, spinal cord and part of its brain. Meanwhile, the planarian worm can even regenerate its head after decapitation and will grow into two new worms when cut in half. 

Scientists have found that the key to regeneration lies in being able to activate special regenerative cells – usually stem cells – and then directing them to regrow the cells that have been lost. Importantly, if we could find a way to boost human regenerative abilities, we could potentially treat many age-related diseases. We could even regrow new organs or limbs to replace any that get damaged or lost. 

Researchers are finding ways to boost the body’s ability to regenerate neural and heart cells, among others. Diseases that could potentially be treated via regeneration include heart disease, arthritis, osteoporosis, neurodegenerative diseases like Parkinson’s and Alzheimer’s disease, or even age-related hearing loss and vision defects. Such treatments would be a massive advancement to help people stay healthy and fit in old age.