Ireland is one of the fastest ageing countries in Europe. A recent reminder of this came with figures for the number of centenarians in the country. While 2016 census data noted 456 people were aged 100 or older, more recent reports indicate the number of centenarians had grown to more than 1,000 in 2025. A number of them spoke about their experience of living through a century to coincide with the publication of the 1926 census by the National Archives.
Longevity research is one of the most rapidly growing areas in science. Because the world is rapidly ageing, ageing matters more. We have finally made great strides in understanding the biology of ageing. All of this is coupled with huge investment chasing the idea of longer, healthier lives. Ireland has similarly invested in ageing research in particular in Tilda, the Irish Longitudinal study on Ageing.
Biological ageing is how ourselves and tissues and systems actually wear, adapt and renew as the years pass. It’s distinct from chronological age, which is the number of candles on our birthday cake. Two people can both be 50 yet have very different biological ages depending on genetics, lifestyle, disease exposure and sometimes sheer luck.
Biological age is often described as a smooth, continuous decline, but that’s a comforting fiction – biological ageing is more like a staircase with suspiciously placed landings around ages 30, 50 and 70.
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Around 30 the first inflection point arrives quietly but decisively when peak cellular repair efficiency begins to taper. The reason for this is not yet clear, but awareness of the inflection points and more care of the factors that influence ageing and over which we have control during these times will make a difference to wear and tear.
By age 50, the second bend in the curb reflects deeper system shifts with hormonal changes, more molecular damage and noticeable changes in physiological systems.
At roughly age 70, the third big inflection point in the process is evident as multiple systems – including the immune system, muscles, bones, heart, lungs and brain – accumulate deficiencies, ultimately presenting as age-related diseases with which we are all too familiar, such as heart attacks, heart failure, high blood pressure, chronic obstructive pulmonary disease (COPD), dementia, arthritis and falls.
So what have we learned about the ageing process and how can we better manage these age-related inflections? The good news is that the majority of the ageing process – between 70 and 80 per cent – is within our control. The remainder is under the jurisdiction of our genes, over which we have little control at present.
The factors under our control are mostly well known – such as physical habits, which still do the heavy lifting. Regular movement, decent nutrition and good sleep all support our body’s repair systems and slow the accumulation of wear and tear. It is this accumulation that eventually tires the cells and leads to cell ageing, and ultimately to cell death.
Ageing isn’t only about maintaining the body, it’s about continuing to use it socially, mentally and emotionally. The earlier you start, the more these benefits compound. But it’s equally important that we recognise it is never too late
But the softer factors that influence ageing turn out to be just as strong an influence on biological processes and disease prevention.
Strong relationships and a sense of community are consistently linked to better health and longer life. These important influences are in decline largely due to demographic changes. Family structures have shifted. Smaller families, higher rates of divorce and separation and more geographically dispersed children mean older adults are less likely to live near or with family. Rural depopulation adds another layer. Younger people move to cities or abroad, leaving older individuals behind in quieter communities.
Humans are not designed to age well in isolation. Solutions for community engagement, continued friendships, remaining active to the end, are urgently required not just for the individual but also for societal and policy planning. Social isolation, loneliness and poor community engagement all feed into a stress paradigm.
Chronic stress keeps the body in a low-level ‘alarm state’ which, over time chips away at resilience. Getting something resembling a work-life balance isn’t just about lifestyle branding, it’s about giving the body and mind enough recovery time to function properly and to repair cell damage accrued during stress.
Then there’s the less measurable but no less important need for having a purpose in life. Purpose feeds into relationships and a sense of community. Much has been written about the need for purpose. Purpose can be quite simply defined as a sense that your life has direction, that what you do matters. It doesn’t have to be grand or world changing. It just has to be personally meaningful and sustained over time. When we have purpose we feel we’re heading somewhere, not just drifting through days. We feel our actions are worthwhile to ourselves and possibly to others.
Purpose is less about what we do but more about how connected we feel to what we are doing. Purpose tends to emerge from engagement rather than being introspective. Most people find purpose by doing things that matter repeatedly until a pattern forms that gives a sense of meaning.
Purpose is not the same as achievement or success. A high-powered career can provide purpose, but so can raising children, volunteering, maintaining friendships, caring for others, learning something new and tending the garden. What gives us purpose at age 25 may not at 55. In fact, people who age well often adapt their sense of purpose as circumstances change and shift.
So, purpose is that ongoing feeling that your time and energy are being spent on things that matter to you in a way that gives your life direction – not necessarily dramatic, rather just not empty. Having a reason to get up in the morning – whether through work, family, volunteering or curiosity – supports mental and physical health and happier longevity. Creativity plays a role here as well; engaging the brain in novel, expressive ways helps to maintain cognitive flexibility and a sense of vitality.
In short, ageing isn’t only about maintaining the body, it’s about continuing to use it socially, mentally and emotionally. And timing matters. The earlier you start the more these benefits compound, quietly stacking the odds in your favour over decades. But it’s equally important that we recognise it is never too late. Even later in life improvements in activity, connection, stress, purpose and creativity can lead to better function both of brain and body, and to a noticeably better quality of life.
The Irish Longitudinal Study on Ageing is a large-scale, nationally representative study, the overarching aim of which is to make Ireland the best place in the world to grow old. Its research has clearly shown that life gets better after age 50. So in Ireland we are doing something right. Let’s keep it up.
Regius Prof Rose Anne Kenny is a consultant in geriatric medicine, head of the Ageing Research Programme at Trinity College Dublin and founding director, The Irish Longitudinal Study on Ageing (Tilda)
