One day, something which you have done forever becomes difficult or impossible to do. Perhaps we forget something and cannot remember what it was. Or we get hurt and it takes us longer to recuperate, or worse still, we never recuperate completely. At such moments in our ageing life, we stop and evaluate, “Am I getting too old?”

Our mind works by categorising things into boxes. Good versus bad, happy versus sad. We are brilliant at doing this. Except we know that in reality things are not so easily categorised. For example, some bad things that happen to us turn out to bring about positive changes in our lives.

This constant desire to place things in boxes clashes with the diffuse nature of reality. This clash is best seen when we try to understand ageing. We would like definitive stages to be able to say that we are old or young and yet nature does not conform to pre-established stages. As with dementia, although most caregivers feel somewhat comforted by the initial diagnosis, the patient has moments of lucidity that seem at odds with the diagnosis.

Geriatricians who study the medical issues of ageing and gerontologists who are concerned with the social aspects of ageing have both failed to define what ageing is. At its simplest we can see ageing in cells and how genetics play a role in cell death. But once we go beyond the cellular structure, the waters become murky.

It is difficult to identify what ageing is. When babies start to age, is that ageing or growing? When do we stop growing and start ageing? If we are honest, we have to confess that we still know very little about ageing.

The longest living person in history was a French woman by the name of Jeanne Louise Calment. She died in 1997 at the age of 122. What is not advertised is that she smoked until the age of 117. She only stopped because she was blind and one time, lighting up her cigarette, she inadvertently set her apartment on fire, which resulted in her having to leave her apartment and go to live in a nursing home. She also lived on a diet of port wine and ate nearly a kilo of chocolate a week. This is definitely not on my list of healthy diets. What Calment illustrates is that the ideas we have about ageing are incomplete.

We still know very little about ageing

Science can, however, help us identify what is true and what is false.

Short people live longer than tall people. Women generally live longer than men. Rich people are more likely to live up to 75 years of age, but then they have no advantage after this age. Older parents have longer-lived children and long-lived parents have long-lived children.

In general some diets are better, but as Calment has shown us, there are always exceptions. By not smoking, eating less meat and less fat and staying slimmer, people tend to live longer. As for exercise, staying active is helpful but even Olympians who are top athletes in their field only live slightly longer than average adults, which might be more an indication of their lifestyle rather than exercise (i.e. they are unlikely to be obese and smoke). And ethnicity does not determine extreme longevity. Although being white has an advantage, it is more likely because of income and education rather than because of genes.

The longest living person in history was French woman Jeanne Louise Calment, who died in 1997 at the age of 122. Photo: Reuters

The ambiguity of ageing is also seen when we observe that most people die before they reach the age of 75, while in contrast, the fastest-growing category of the population in developed countries is for those aged over 100 (not in Malta.) What distinguishes these two very different groups is attitude.

Those that have a positive view of ageing, seeing ageing not as a negative thing but as a blessing, tend to live longer. In a 10-year study, people aged 72 and older with a positive attitude towards ageing were more likely to recover from a severe disability than those with negative stereotypes.

In contrast, participants in the Baltimore Longitudinal Study of Ageing who held negative age stereotypes had a greater chance of experiencing memory decline and heart attacks 30 to 40 years into their future.

These same participants with positive age perceptions lived 7.5 years longer than those with negative perceptions. In one of the largest studies, David Snowdon found that nuns who had a more cheerful disposition when they entered the nunnery were likely to live longer and free from dementia 25 years later.

Since these are long-term studies, we can identify what comes first. Being happy and content with your lot seems to be the deciding factor of how well we age. The ambiguity comes when we try to control how we age.

Calment never worked, she lived a leisurely life of hiking, fencing, cycling, playing tennis, swimming, rollerskating, playing the piano, hunting and mountaineering. Did I mention that she ate over a kilo of chocolate a week? If that is not the definition of happiness, I do not know what is. Being happy with your lot is the first stage at understanding ageing.

Mario Garrett was born in Malta and is currently a professor of gerontology at San Diego State University in California, US.