In recent months, centenarians interviewed by this newspaper have variously attributed their longevity to "hard work, staying positive and the pint of Guinness", "fresh air, golf and bridge" and "healthy eating, healthy living and all things in moderation".
However, data released to The Irish Times by the Department of Social Protection shows differences in longevity in different counties with higher-than-average numbers of centenarians in Connacht – particularly Co Mayo – and Co Longford.
A total of 402 centenarians were in receipt of an old-age pension from the department as of the last day of 2014, with more than a fifth located in Dublin.
But when the number of centenarians is mapped using population figures for the 26-counties a different picture emerges.
Mayo have the highest number of centenarians at 2 per 10,000 population – proportionally two-and-a-half times more than their counterparts in the capital.
Figures for the past four years show a consistently high number of Mayo-based centenarians per head of population – in 2013 only Longford had a higher number of 100-plus-year-olds, while, in 2012, only Mayo’s neighbouring counties, Roscommon and Sligo, surpassed it.
All the aforementioned counties also recorded a high number of centenarians last year – Longford had 1.8 centenarians per 10,000 population followed by Sligo and Galway at 1.4, Donegal and Monaghan at 1.3, with Roscommon and Clare at 1.2.
At the other end of the scale, either Carlow or Laois recorded the lowest number of 100-plus-year-olds per head of population for the past four years running.
However, given the short time period for which data is available and the small numbers involved, the figures represent a snapshot in time rather than a definitive trend. And, of course, individual socio-economic factors may have a bearing on whether someone claims a pension or not.
Tom Sharf, a professor of social gerontology and director of the Irish Centre for Social Gerontology at NUI Galway said that, while its research has found a greater concentration of older people living in rural Ireland than in urban areas, this can be put down to migration patterns (young people moving to urban centres to find work) rather than indicating longevity.
“There is a field of centenarian studies internationally, but we have little of this strand of research in Ireland. There’s a big gap there,” he said.
Similarly, Professor Des O'Neill, consultant geriatrician at Tallaght Hospital pointed to research carried out on the health of centenarians and nonagenarians (a person between 90 and 99 years) in Northern Ireland, but that little or no research had been carried out on this age group in the Republic. "Such research would be hugely valuable in teasing out the factors involved in healthy ageing," he said.
There are, however, some trends we can draw from the available data. Although the majority of the 402 centenarians in receipt of the old age pension at the end of last year lived in the Republic of Ireland, 5 per cent, or one in 20, live either in Northern Ireland or overseas.
The number of centenarians in receipt of the State pension has risen in recent years – 355 centenarians were in receipt of a State pension in 2011, rising to over 400 last year.
Women were much more likely than men to make it to their 100th birthday – almost 88 per cent of centenarians in receipt of a State pension at the end of last year were female.
Almost 90 per cent of Ireland’s centenarian pensioners were between 100- and 103-years of age, or 360 centenarians in all.
However, 25 people in receipt of a State pension were aged 104; seven had reached the ripe age of 105; there were six 106-year-olds; two aged 107; one 108-year-old and one 109-year-old.