Why do our bodies age? - Monica Menesini

Summary

In 1997, Jeanne Calment set a record by living to 122 years, a feat few humans are likely to match due to the limits of our biology. Aging is a complex process driven by genetic damage, mitochondrial decline, epigenetic changes, and the loss of regenerative abilities. As we age, cells become senescent, telomeres shorten, and stem cells diminish, all of which hinder the body’s capacity to repair itself. Despite these challenges, future technologies like gene therapy and nanobots may extend human lifespan, raising important questions about whether living longer is truly desirable.

Takeaways

• 😀 Jeanne Calment, the oldest known person, lived to 122 years and 164 days, a record that remains unbroken.
• 😀 The challenge of extreme aging is that human bodies are not built for longevity beyond 90 years, with aging being a complex biological process.
• 😀 Aging is the result of both intrinsic processes and environmental factors, such as sunlight, toxins, and poor diet, which cause molecular and cellular changes.
• 😀 The decline in the function of mitochondria, responsible for producing energy in cells, is a key factor in aging, leading to cellular and organ deterioration.
• 😀 Epigenetic changes in gene expression, which occur over time, can contribute to degenerative diseases like Alzheimer's and accelerate aging.
• 😀 Cellular regeneration declines with age, with telomeres shortening every time a cell replicates, eventually stopping cell replication and leading to cell death.
• 😀 Aging also involves an increase in senescent cells, which stop replicating in response to stress but hinder tissue renewal and regeneration.
• 😀 Stem cell depletion with age results in reduced regenerative potential, affecting tissue renewal and organ function.
• 😀 As cells age, they lose the ability to maintain protein quality control, leading to the accumulation of damaged proteins and toxic substances, which can cause cell death.
• 😀 Intercellular communication also weakens with age, contributing to the overall decline in the body’s functional abilities.
• 😀 Despite limited understanding of aging, future technologies like cell-repairing nanobots and gene therapy may offer possibilities for extending life, raising questions about whether we should want to live longer.

Q & A

Who holds the record for the oldest known person in history, and how old were they?

Jeanne Calment holds the record for the oldest known person in history, living to the age of 122 years and 164 days.

What extreme claim was made regarding Jeanne Calment's age?

A millionaire pledged $1 million to anyone who could break Jeanne Calment's record for longevity.

Why is it unlikely for humans to live past 90 years of age?

Human bodies are not built for extreme aging, and our natural capacity to live is set around 90 years.

What is the scientific challenge in defining aging?

Aging is difficult to define strictly because it involves complex processes, from genetic changes to environmental interactions, which all contribute to the body's gradual decline.

How do environmental factors like sunlight and toxins contribute to aging?

Environmental factors such as sunlight and toxins in the air, water, and diet interact with the body's cells and molecules, causing structural and functional changes that accelerate aging.

What is the role of mitochondria in aging?

Mitochondria produce ATP, the main energy source for cellular processes. They are particularly prone to damage, and their decline contributes to cellular and organ deterioration as we age.

How does genetic damage accumulate in the body over time?

As we age, our bodies accumulate genetic damage in the form of DNA lesions, which occur during DNA replication and even in non-dividing cells. This damage affects cell function and contributes to aging.

What are telomeres, and how do they impact aging?

Telomeres are protective regions at the ends of chromosomes that shorten with each cell division. As telomeres become too short, cells stop replicating, which slows the body's ability to renew itself and contributes to aging.

How does cellular senescence relate to aging?

As we age, cells become senescent, meaning they stop replicating. While this response can prevent cancer cell growth, it also hinders the body's ability to regenerate healthy cells.

What happens to stem cells as we age, and how does it affect the body?

Stem cells decrease in number and lose their regenerative potential with age, which impairs tissue renewal and the maintenance of organ functions.

What is the impact of impaired protein quality control on aging cells?

As cells age, their ability to maintain protein quality declines, leading to the accumulation of damaged and toxic proteins, which can result in excessive metabolic activity and potentially fatal consequences for the cells.

What future technologies might extend human lifespan, and what are some of the possibilities?

Future technologies, such as cell-repairing nanobots and gene therapy, could potentially extend human lifespan by repairing cellular damage. However, it's still uncertain whether these technologies will be able to significantly alter the aging process.

Do we want to live longer than our current lifespan, and how might our curiosity about aging drive future advancements?

While there is no consensus on whether we should live longer, our curiosity about aging and the pursuit of extending lifespan may lead to innovations in medicine and technology that could alter the natural course of aging.