Scientific clues to unlock aging

Ever wondered why different living beings have different life spans? Why do some animals, such as mouse, have an average lifespan of 3 years, while others, such as tortoises, can live up to 200 years? Is the process spontaneous or regulated?

Aging is a fundamental and universal phenomenon, which we all are familiar with. It is inevitable and happens during the entire lifespan of an individual. Despite being a universal process, it has never been easy to define aging. On one hand, aging results in growth, development and maturity, while on the other, it leads to a decline in physical strength and functions.

Why do we age? Our body is a complex machine, made up of billions of cells. As time goes by, just like any other machine, the body also experiences wear and tear. At the cellular level, old cells start dying. With time, when cell death overpowers cell repair and production, the body is left with few healthy cells and a lot of accumulated damage which spreads from cells to tissues to organs to organ systems to the whole organism. In addition, the accumulation of mutations and damage to DNA as our cells are exposed to various stressors like free radicals (the byproducts of biochemical reactions), UV radiation from the sun and even environmental pollution also contribute to the aging process.

The issue lies not in the process of aging itself, but rather in the diseases that are linked to it. Growing old is inevitable, but with older age comes a heavier burden of age-related diseases, like cataracts, arthritis, pulmonary diseases, diabetes, cardiovascular disease, hypertension and dementia. One way to face this economic and social liability is to look at the major risk factor common to all these diseases- that is aging. The magnitude of this problem can be estimated by the fact that age-related disorders have accounted for 2/3^rd of the total population dying all across the globe.

We need to discover ways to reverse or delay aging. According to an ancient myth, Gilgamesh, the ancient Sumerian king, embarked on a quest for immortality, seeking the secret to eternal life. His quest resonates with modern studies of longevity, where science and technology drive the search for eternal life.

Scientists now use the model organisms such as mice (Mus musculus), rats (Rattus domestica), fruit flies (Drosophila melanogaster), or roundworms (Caenorhabditis elegans) to understand the complex mechanism of aging. Studies in these model organisms have suggested that calorie restriction can lead to increased lifespan and improved health span. Mutations in a single gene called daf-2, increased the lifespan of Caenorhabditis elegans by two times!

Studying the genome of long-lived animals such as the giant Galapagos tortoise has revealed the presence of unique genes for DNA repair, telomerase and nutrient sensing-cell inhibition. Interestingly, the invertebrate Hydra seems immortal due to its regenerative ability allowing the animal to restore any body part in case of injury. Due to a high proportion of stem cells, the hydra can completely regenerate itself when cut into pieces!

Other long-lived animals such as lobsters, clownfish, birds and bats have developed additional ways to stay healthy for a long time. This includes enhanced telomerase activity, DNA damage repair mechanism, controlled cell proliferation, cancer prevention, better immunity as well as anti-oxidative mechanisms.

However, the big challenge lies in figuring out how to apply all this animal knowledge to help humans live longer. This is something scientists are still actively working on for the future.

Can we actually be immortal? The intention of gerontology studies has never been to promote immortality.  In reality, achieving true immortality is currently beyond scientific capabilities, and the focus of researchers is on extending healthy lifespans and improving the quality of life in old age rather than achieving literal immortality. Many experts believe that a more reasonable goal is to target the underlying processes of aging to delay its onset and reduce age-related diseases.

What can we learn from aging studies Aging studies offer crucial insights into the biological, genetic, and environmental factors shaping the aging process. These investigations identify biomarkers, inform interventions for healthy aging, and target age-related diseases like Alzheimer’s and cardiovascular conditions. Gerontologists are focussed not only on extending lifespan but also on enhancing health span, promoting overall well-being in older individuals.

The wealth of knowledge has contributed to the development of personalized medicine and informed public health policies to address the unique needs of an aging population.

Scientists are working to better understand the intricate details of the aging process and to find ways to promote healthier aging. While we can’t stop aging altogether, we are learning how to slow it down and improve the quality of life as we grow older. This research might one day lead to treatments that help us age more gracefully and maintain our vitality for longer periods.