Is There a Limit to Lifespan?

Today humans are living longer than ever before. However, the downside is that a lot of that lifespan is spent in sickness and need of care. What if we could stop this?

Why Do We Die?

As people age, our bodies wear down and our metabolic processes are no longer able to keep up with the bodies’ need. Think of it like this: You have a new car and a young mechanic. The car runs well but if there is ever a problem, the mechanic can solve it quickly and easily. As time goes on, the car starts to need more maintenance. However, the mechanic is also older and can’t fix everything. This is the same for your body in old age.

Death doesn’t stem from simply old age. We only die because one of our important parts break and can’t be fixed. The older we get, diseases take over our body and we don’t have the tools to fight them off.

What is Human Longevity?

Human longevity is the idea of increasing the human lifespan. Through improvements in medicine, scientists have thought of ways to stop your body from wearing down and prevent diseases from taking over. Scientists believe that we can make everyone healthy to the current maximum age and some even believe we can push life indefinitely.

The idea isn’t necessarily to create eternal youth or never-ending aging. Longevity is increasing the period of health (the healthspan) and slowing down the road to death. Death won’t end even if aging does. We don’t necessarily have to live forever, just a little longer and healthier to get everything done.

Longevity Research Now

Arguably, any health treatment is a longevity treatment. However, curing certain the root cause of aging will make a much bigger difference. The largest area of longevity research is with telomeres.

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Image credit: Genome Research Limited

Telomeres are caps that protect the tops of chromosomes when cells divide. They are comparable to the plastic tips at the end of shoelaces. Because the cell replication process is imperfect, when a cell replicates, the telomeres shorten. When they become too short, the chromosome can no longer replicate and the housing cell will undergo senescence.

This shortening is associated with many age-related conditions, such as diabetes, hypertension, Alzheimer’s disease, and types of cancer. Luckily, while studying immortal organisms such as Tetrahymena (pond scum), scientist Elizabeth Blackburn has discovered that their telomeres never shorten. From there, she has been trying to replicate this process in mice. The trials were a success with treated mice life expectancy increasing by 30%. This is a strong proof of concept for increasing life in humans.

The Ethics of It All

While we haven’t completely cracked the code for aging, some people believe that we shouldn’t continue research at all. It all stems from the question: If we could end aging, should we?

The idea of living indefinitely makes many people uncomfortable. However, how can we tell the difference between life extension and longevity? We’re already trying to prolong life through medicine. Chemotherapy for cancer and lung transplants are all trying to extend life. We’re simply just doing it ineffectively so our lives end anyway. The most effective way isn’t to treat the disease once it happens, but to prevent it from ever happening. Using telomere research, we can prevent disease just like medicine is already doing.

If we imagine a world in which ourselves and our loved ones live an extra 100 years in good health, what would we do? Would we spend more time figuring out our skills? How much more time would we spend learning? Would stress go away or get worse?

We’ve only scratched the surface of research for human longevity. There is so much more to learn and to consider. Perhaps then, we can find a consensus on the limits of lifespan.