The number of centenarians in Europe
3.4 Europe vs. Japan
The final table compares centenarian figures for 2006 for Japan and the 27 European countries of our study (26 countries for the CR calculation).
If the absolute number of centenarians appears to be much higher in Europe, being 57,306 centenarians in total in 2006 for the 27 countries of our study versus 27,142 in Japan, the speed of increase in Japan is much higher than in Europe. Indeed the number of centenarians was multiplied by a factor of 4.2 during the period 1996-2006 in Japan while it was only multiplied by a factor of 2 in Europe. Therefore, if these rates of increase hold in both regions, in 10 years the number of centenarians should be quite similar. The 10-year increase factor reached 4.5 for the female Japanese centenarians versus ‘only’ 3 for their male counterparts. This exceptionally strong increase in the number of centenarians was also observed during the period 1986-1996 (Robine and Saito, 2003). Interestingly both regions exhibit the same centenarian sex-ratio, i.e. one male for six females. The most intriguing part of this comparison is the CR value which reached 158 centenarians for 10,000 Japanese surviving at age 60 in 1966. It is three times higher than in Europe and 1.6 times higher than in France which has the highest European CR. When analysed by gender, the CR reached 49 for the Japanese male centenarians and 259 for the female centenarians in 2006. In other words, 259 Japanese females out of 10,000 aged 60 in 1966 became centenarians by January first, 2006. Disregarding the small size of the European birth cohorts born during WW I, these comparisons suggest that there is still a lot of room for future centenarian increase in Europe.
Table 4: Europe compared with Japan: Number of centenarians in 2006 and various centenarian indicators, by sex
Source of data: Human Mortality Database (HMD); *Slovenia excluded
3.5 Discussion
Our study of the increase in the number of centenarians in Europe, the first to our knowledge to cover so many countries, produces several interesting results. First, it confirms at the European level and for the most recent years that the number of centenarians is doubling on average every ten years, results already found by James Vaupel and Bernard Jeune for half a dozen Western and Nordic European countries (Vaupel and Jeune, 1995). Indeed, from 1976 to 2006, the number of centenarians almost exactly doubled every decade in the 27 European countries studied. Second, our study disclosed a wide range of values across the European countries for several centenarian indicators such as the centenarian sex-ratio or the 10-year increase factor. While we did not observe a clear geographical pattern in the distribution of the centenarian sex-ratio in Europe, we showed there was a strong geographic gradient, from the north to the south of Europe in the 10-year increase factor, with a much stronger increase factor in the south for the last ten years. Is it a question of climate or is it a question of culture, dealing with both the local diet and the local way of providing daily care to the oldest-old? Only local multifactorial research may tell. Third, the analysis of CR showed that the significance of the centenarian numbers is not the same between countries like France in which 157 females out of 10,000 aged of 60 in 1966 became centenarians in 2006 and countries like Bulgaria where only 17 females out of 10,000 did. Comparison with Japan indicated that values like 260 out of 10,000 can be reached by women under the 1966-2006 Japanese living conditions. Fourth, on a wider scale, encompassing Europe and Japan, the centenarian sex ratio seem to be relatively constant, around one male centenarian for 6 female centenarians. Local variations from this figure do not have any obvious explanation. Fifth, countries with a high number of centenarians, such as England & Wales in 2006, may exhibit a relatively low 10-year increase factor while countries with fewer centenarians, such as Spain, may display a much higher 10-year increase factor. In these conditions, a country’s ranking in the number of centenarians is not guaranteed for long. In particular the number of Japanese centenarians may outnumber the European ones in a decade or so if the current 10-year increase factors hold in both regions.
From a demographic perspective the increase in the number of centenarians is due to the fall of mortality among the oldest old and particularly above the age of 80 years, (Thatcher, 1992 and 2001; Vaupel and Jeune, 1995; Robine et al., 2003; Robine and Paccaud, 2005). The consequence of these demographic changes is an increase in the number of the oldest people and therefore before increasing the centenarian numbers, to increase the nonagenarian numbers. In Italy, for instance, the number of nonagenarians, aged of 90 to 99 years, increased from 18,000 in 1946 to 497,000 in 2006 for a total increase factor of 27 (see Figure 14) whereas the number of centenarians increased from 59 in 1946 to 9,150 in 2006 for a total increase factor of 155. The successive nonagenarian figures in Italy have been 35,000 in 1956, 53,000 in 1966, 92,000 in 1976, 138,000 in 1986, 259,000 in 1996 and eventually 497,000 in 2006. The centenarian figures should be taken as an indicator of the oldest-old population increase not merely as strictly centenarian quantities.
Figure 14: Increase in the number of nonagenarians (90-99) in Italy since 1946, by sex
Source of data: Human Mortality Database (HMD).
Very old people are frail people and recent ongoing studies in Japan, such as the Tokyo centenarian study (Gondo et al., 2006), suggest that the functional health status of the centenarians is worsening as their number is increasing, confirming a previous study made in Okinawa (Suzuki et al., 1995). Conversely Danish studies show that centenarians are in better functional health in 2005 than in 1995, in a country where the number of centenarian increased slowly (Engberg et al., 2008a and b). Last year A five-country project, known as 5-COOP and involving research teams in Denmark, France, Japan, Sweden and Switzerland, started to examine the feasibility of a common study focusing on the potential trade-off between the level of mortality selection from age 80 to age 100 and the functional health status of the centenarian survivors. This study will help to better understand to what extent the current lengthening of life is associated with a worsening of the functional health status of the oldest old.
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Tags: Centenarians Europe, Older workers dismission