LONGEVITY AND THE SECRETS OF CENTENARIANS

Aging of the world populations represents one of the most remarkable success stories of medicine and of humankind. Hence, the search for ways to prolong health expectancy is a primary goal in medicine. Human life expectancy increased extraordinarily during the last century worldwide. Life expectancy at birth has almost doubled in most developed countries over the last century, with the oldest group being the most rapidly growing segment of the population. The number of centenarians in Italy is over 16.000 and the number is over tripled in few years (they were 5.000 in 2001). Among older population, centenarians may be considered the best example of successful aging. The capacity to avoid, delay or limit aging-related diseases has been proposed as one of the mechanisms that may help to explain the successful aging in centenarians. In the world there some areas called Blue zones rewarded by longevity. Aging is a multifactorial and progressive process, that takes place at different levels, affecting practically all-living organisms. Currently, there is growing evidence that there are modifiable factors that contribute to ageing per se, and particularly to longevity (i.e. diet, physical and mental activity). These factors may interact with the ageing process and may alter the susceptibility of an individual to develop age-associated diseases. There is currently much promise in research that provides information about the underlying biology of ageing and longevity, which has unveiled possible interventions to slow the ageing process, including a healthy lifestyle in terms of nutrition, exercise, and smoking cessation, as well as new discoveries that result from basic research. Also in Sicily, an island in the center of Mediterranean sea, there are some areas where there is a very high concentration of centenarians. In Giuliana (Palermo), a small village of just over 2,000 souls, in the last thirty years, 21 people have reached one hundred years, with a percentage (3.35 per thousand) that exceeds the regional average (0.20 per thousand) and national (0.25 per thousand). In order to explain this evidence, there is a growing number of hypothesis that consider a combination of genetic factors and lifestyle aspects to elucidate the exceptional longevity of centenarians, able to overcome the most frequent mortality cause. Genetic component affects not more than 25% in the phenomenon of longevity. Several lines of evidence have led to the general acceptance of a link between low-grade inflammation (inflamm-ageing) and the ageing process. Many age-related diseases, such as cardiovascular diseases, atherosclerosis, diabetes mellitus type 2, COPD, neurodegenerative diseases and cancer are closely associated with chronic inflammation. There is growing evidence of the influence of diet and physical activity on the quality of life during aging, since these factors are major determinants of the aging process itself as well as of the development of age-associated diseases. The assumption of a link between inflammation and age-related diseases raises the possibility that lifestyle and dietary interventions aimed at slowing down inflammation may also increase longevity. A number of studies in different populations have established a beneficial antioxidant and anti-inflammatory role for many components, typical of Sicily and of the Mediterranean diet (i.e. vegetables, fruits, olive oil, wine). This evidence has definitely set up the role of adherence to a Mediterranean diet as a model of healthy eating which contributes to longevity.