The research fraternity has had a mixed bag of responses to the recent study by Yang et al. that claims to reverse aging. David Sinclair, researcher at Harvard and author of the book Lifespan, along with his colleagues, claimed that six new-age chemical cocktails have the potential to improve vision and extend the lifespan.
This study claims that aging can be reversed by chemically reprogramming adult stem cells. Until recently, researchers reaped the potential benefits of stem cells (cells that can develop into multiple any type of cells in the body) by employing them in stem cell therapy (a medical procedure of replacing damaged or dysfunctional cells with fully functional ones) and stem cell transplant (a procedure of infusing stem cells into an individual to replace the damaged cell). The latest developments open up multiple new avenues.
Can chemicals reverse aging?
The 2023 study on mice made them younger by a few years after just four days of the chemical cocktail treatment. This included prescription-only drugs such as tranylcypromine and valproic acid (VPA) that help in neurodegenerative conditions. The chemical cocktail alters adult cells that have far less potential and more risks than stem cells, opine experts.
“Aging is a complex biological process. Altering cells to reverse aging may have far-reaching consequences beyond what is currently understood,” explains Sharmili Roy, post-doctoral researcher, division of oncology, department of medicine, Stanford University School of Medicine, Stanford.
Role of stem cells in reversing aging
The age of an individual is determined by stem cells. “These cells grow and reach their prime before decaying. Each cell is time-bound,” explains Dr Debanjan Banerjee, consultant neuropsychiatrist, Apollo Multispeciality Hospitals, Kolkata. People live up to the sum total of the age of all the cells in the body
Adult cells are stem cells that grow to have a specific genetic function, explains Prof T S Keshava Prasad, deputy director, Centre for Systems Biology and Molecular Medicine, Yenepoya (Deemed to be University), Mangaluru, Karnataka. “These cells can become a part of the brain, blood, heart muscle, skin and other body parts. This process takes place through programming from one’s own DNA in their surroundings,” explains the professor. Conversely, in this study by researchers from Harvard, the genetic function of adult cells is altered through chemical reprogramming.
Combating cell death with stem cells
“Cell death has been the biological cause of multiple degenerative conditions such as dementia, Alzheimer’s, Parkinson’s, as well as stroke and depression,” explains Dr Banerjee.
One of the significant contributions of regenerative medicine in treating life-threatening diseases such as cancer and other genetic disorders has been stem cell transplants, explains Dr Naganath Narasimhan Prem, geriatrician, Jaslok Hospital and Research Centre, Mumbai. He elaborates, “Here, stem cells from bone marrow, umbilical cord, peripheral blood cells or even amniotic fluid in rare cases, are extracted from either a healthy donor or healthy part of the individual. They are then transplanted to replace the damaged cells.” This treatment is widely used in blood cancers such as leukemia, lymphoma, myeloma, aplastic anemia, sickle cell disease and neuroblastoma. But this procedure does not ensure a complete cure, Dr Prem adds.
“Stem cell therapy also operates on a similar principle,” explains Roy. She adds, “By replenishing the damaged cells with fresh, healthy ones, the therapy endeavours to reinstate normal tissue function and enhance an individual’s overall well-being.”
Age reversal: Risks of chemical reprogramming
While the study shows promising results, it has its own risks, say experts. They elaborate:
Immune system response
“One critical factor is the immune response triggered by the chemical-infused cells,” points out Roy. She explains, “The immune system is highly complex and finely tuned to recognize and defend against foreign entities. When altered cells are introduced, it may mount a response ranging from mild inflammation to adverse reactions.” She also says, the chances of unintended interactions between infused cells and the surrounding tissues or organs are higher, says Roy.
Interaction with surrounding tissues
Prof Prasad adds, “Humans are complex compared to mice. Moreover, the potential risks of chemical reprogramming to alter cells are much higher in a non-controlled environment vis-à-vis a controlled environment.”
The altered cells may behave unpredictably, potentially leading to unforeseen health issues and complications, says Roy. If these altered cells grow without control, the risk of tumor or cancer heightens, cautions Dr Banerjee.
Reversal of aging: A boon with a disclaimer
The new research, however, carries the disclaimer: Aging is the single greatest contributor to human disease and suffering, these advances cannot come soon enough. Roy adds that long-term effects and ethical considerations also play crucial roles in determining the feasibility and safety of such therapies.”
Commenting on the David Sinclair research, Dr Banerjee raises his concerns and says, “Whenever science has made tall claims with anti-aging experiments, everybody is thrilled. But, as a dementia specialist, I will only be elated when science can identify and delay the progression of neurodegenerative conditions with lesser risks. Dementia and other neurodegenerative conditions cannot be cured with medicines, nor do they have early intervention methods. Hence, the focus on such disorders while trying to reverse aging could be beneficial to an army of affected population who could otherwise be left in a highly vegetative state.”
Aging healthy: A balanced way forward
Dr Banerjee points out that an extreme step against nature’s law has never helped anyone. “Aging is not just dependent on biological factors. Social, psychological and ecological factors also determine aging.” He adds, “Healthy aging is marked by helping the elderly overcome their feelings of isolation, desertion by siblings or children, post-retirement feelings of emptiness, lack of socialising and much more. Correcting these issues, too, can help delay the death of cells and add to healthy aging.”
Takeaways
- The David Sinclair research on chemical reprogramming of cells claims six chemical cocktails can reverse aging.
- From the study currently done on mice, it appears that human trials will take time.
- Experts warn that the chances of unintended interactions with other tissues, immune system response and other factors must also be considered.
