Staying young

As more people in developed countries are living longer and the elderly comprising a significant proportion of the population, the best brains and laboratories are researching why we grow old.

Divisions are sometimes made between the young old (65–74), the middle old (75–84) and the oldest old (85+). However, chronological age does not correlate well with functional age, i.e. two people may be of the same age, but differ in their mental and physical capacities and some at 85 may play golf and be mentally alert, while another at 65 may be bedridden with diabetes, stroke and dementia.

The term “ageing” is somewhat ambiguous, but refers to the process of physical, psychological, and social change. Some dimensions of ageing grow and expand over time, while others decline. Reaction time, for example, may slow with age, while knowledge of world events and wisdom may expand, explaining why the proportion of elderly among politicians tends to be high. Research shows that even late in life potential exists for physical, mental, and social growth and development.

What causes the body, with all its organs and tissues, to grow old? Why does the skin wrinkle, hair gray, list of diseases like diabetes, blood pressure, cataract, and heart problems grow long, why do we start slowing down, and also why do we become prone to a variety of cancers?

The process seems to start with cells of our body showing signs of ageing, called senescence, that occurs due to the progressive shortening of one of its parts called telomere, each time the cell divides; when the telomere becomes too short, the cell dies. The length of telomeres is therefore the “molecular clock”. And what maintains the telomere length is an enzyme called telomerase.

Why then does the telomere shorten quickly in some, and how can we keep our telomerase enzyme levels high? In 2007 researchers at the Salk Institute for Biological Studies, identified a critical gene that specifically links eating fewer calories with living longer and showed that the gene pha-4 regulates the longevity response to calorie restriction. Semi-starved rats live much longer than their well-fed ones, and slim beauty pageants may actually live longer than their wholesome counterparts.

Apart from the role of longevity determining genes (LDG), cumulative tissue stress arising from liberation of oxygen radicals during cell metabolism has been another suspect. Aging tissues are deficient in antioxidants such as tocopherol, ascorbic acid and retinol that are normally found in fresh fruits and vegetables; hence the recommendation of 5 helpings of these every day. Whether the synthetic antioxidants sold as capsules do any good to keep our tissues young is yet to be proven.

Researchers have now identified compounds that can actually increase telomerase levels and therby stop the process of ageing. Resveratrol, Rapamycin, acetyl-Lcarnitine and alpha-lipoic acid are some of them currently undergoing research.

As the quest for the etrnal youth continues, the ancient “Parijaat” trees standing majestically in Barabanki and Sultanpur, and fabled to have provided agelessness to our gods and godesses, could hold the secret!