When we age … what really happens inside our bodies

By Sunil Saxena

Have you ever wondered why human bodies aren’t built to last forever?

Mankind has been searching for answers to this question since time immemorial. But it is only now that researchers have identified eight physiological factors that contribute to human ageing, leading to death.

These changes happen at the level of our cells and slowly eat into their functioning, leading to tissue and organ damage.

So, what are these changes? How do they make us age, and finally die?

The first is genetic damage. As our DNA replicates over the years, it accumulates tiny errors, which scientists call DNA lesions. This damage happens when our cells divide. It also happens in those cells that don’t divide. But the result is the same. DNA Lesions affect the ways our cells function and can contribute to age-related diseases.

The second is the effect of DNA damage on mitochondria, which are the power plants of our cells. This damage leads to decreased energy production and cellular dysfunction. Damaged mitochondria can produce harmful reactive oxygen species, which can further damage DNA and other cellular components.  When this happens, it’s not just the cells that suffer—whole organs start to deteriorate too.

The third change is epigenetic alterations. These are changes in how our genes are expressed. Genes that are mostly silent in newborns become overly active as we age, leading to degenerative diseases like Alzheimer’s.

The fourth is the effect of cell replication on telomeres, which are the protective caps at the ends of our chromosomes. Every time a cell replicates, the telomeres, get shorter. When they get too short, the cell can’t replicate anymore and dies. This slowdown in cell replication leads to tissue ageing and decline. Finally, it affects our body’s ability to renew

Fifth, as we age, our cells can also become senescent, which means they stop dividing. This response also increases with age, halting cell growth and reducing our body’s ability to repair itself.

Sixth, stem cells, which are like the body’s repair workers, lose their unique ability to divide endlessly and replenish other cells as we get older. This decrease affects the renewal of tissues and the maintenance of our organs. Stem cell dysfunction can contribute to age-related diseases, such as Alzheimer’s disease and type 2 diabetes.

Seventh, ageing cells lose their ability to maintain quality control over proteins. Damaged proteins start to build up, and this can cause excessive metabolic activity, sometimes with fatal consequences for the cells.

Eighth, intercellular communication, that is communication between our cells starts to break down. Just like in any relationship, when communication fails, things don’t work as they should, and our body’s overall function starts to decline.

In addition to these cellular changes, ageing is also associated with a decline in various bodily functions. Our immune system weakens, our metabolism slows, and our hormones change. These changes can contribute to a wide range of age-related health problems, such as increased risk of infection, obesity, and osteoporosis.

And let’s not forget the environmental factors like sunlight and toxins in the air or food. They change the way our cells and molecules work. Over time, these changes lead to the decline of our cells and, eventually, the failure of our organs.

But there’s still so much we don’t understand about our bodies and ageing.

What we can say with certainty is that our bodies are pretty amazing. Every day is a new opportunity to learn, grow, and make the most of the time we have.

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