Healthier behaviors and lifestyle factors, not genetic markers, favor population longevity in Italian and Grecian areas with longer average lifespans called Longevity Blue Zones.(Selitbul | iStock)
· In Sardinia and Ikaria, Longevity Blue Zones (LBZs) in Italy and Greece, people over 90 report high optimism and self-rated health.
· The social support of aged adults in these regions may spur their optimism and drive longevity.
· Some of the factors found to have weaker associations with increased longevity include education level, non-smoker status, and not consuming alcohol.
What makes a person live longer? Is it lifestyle, good genes, or just plain dumb luck? Nailing down the attributes — whether genetic, environmental, or behavioral — that separate exceptionally long-lived individuals from the rest can help researchers figure out what makes us live longer. That’s why aging researchers have flocked to Longevity Blue Zones (LBZs), areas with unusually high numbers of the oldest of aged adults (nonagenarians over age 90), to analyze longevity attributes.
Pes and colleagues from the University of Sassari identify longevity factors shared by two specific LBZs: one in Sardinia, Italy, and the other in Ikaria, Greece. Published in Mechanisms of Ageing and Development, their comparisons showed that LBZ nonagenarians display demographic, lifestyle, and genetic traits that are different from the traits of the nonagenarians from other populations surrounding regions of Italy and Greece. Notably, a greater proportion of these Italian and Grecian LBZs are still married or share their lives with relatives or partners and received higher self-rated health and optimism scores. Findings from the study indicate that public health-related policies like optimism-promoting long-term care may contribute to healthy aging more than biological factors like genetics.
“These features may be seen as possible positive factors related to staying healthy and, maybe, living longer, despite the existence of other unfavorable conditions such as a greater prevalence of chronic diseases and smoking,” propose Pes and colleagues.
To demonstrate the unique longevity profile of the LBZs, Pes and colleagues compared the probabilities of surviving past age 90 in Sardinia, Italy, and Ikaria, Greece, to surrounding regions in each country. Sardinian men and women both have about a 13% chance of surviving past 90, while Italian men have just a 3.1% chance and women have a 9.6% chance. The story is similar in Greece, where Ikarian men and women have a 3.3% and 8.8% chance, respectively, and Grecian men and women have a 2.3% and 6.3% chance, respectively. These odds of surviving to 90 years old result in substantially higher numbers of aged adults reaching 90 per 100,000 people and illustrate the unique longevity profiles of Sardinia and Ikaria.
So, what’s driving the lifespan extension in the LBZ? To find what unique characteristics distinguish the nonagenarians from the rest of the aged population, Pes and colleagues analyzed lifestyle and health indicators. Compared to their respective countries, they found higher levels of nonagenarians who had not lost a spouse and higher optimism in the LBZs. Pes and colleagues found fewer nonagenarians living alone, indicating that aged adult social support may contribute to optimism in these regions.
Pes and colleagues conducted a genetic analysis of the nonagenarians in the LBZs and found lower numbers who inherited specific gene markers in the aging-related genes ApoE4 and ApoE2. But according to Pes and colleagues, “Compared to behavioral and health indicators, the impact of genetic factors might be relatively less important in the LBZs.” They go on to say that future research is needed to identify changes in gene activity (epigenetics) that may influence longevity since the current study didn’t look at these factors.
Other lifestyle factors with weaker associations to longevity included smoking, alcohol consumption, and years of education. For men but not women in each region, quitting smoking or not smoking was a statistically significant factor contributing to longevity. And even though previous studies have shown that red wine consumption in these areas contributes to longer lives, Pes and colleagues did not find a substantial association here. More education was associated with longer lives in men and women of Ikaria but only women in Sardinia, pointing to another, more weakly contributing factor to healthy aging.
“A large part of the population has long-term living arrangements entailing better care of elderly people, more optimism in the advanced age, perhaps, longer survival,” Pes and colleagues said about the LBZs when pinpointing what factors contribute to the populations’ longevity. This raises whether public health-related policies that improve our care for the aged population may extend lifespan. Continued LBZ research can shed light on the effects of long-term elderly care and whether more can be done to boost optimism among aged populations.
One limitation to the study includes that the Sardinian population was compared to three distinct genetic populations from Northern, Central, and Southern Italy. These three regions have major cultural and genetic differences, which may have introduced variables that complicate the study like smoking and drinking habits or different genetic compositions. Future LBZ research that reduces or eliminates these confounding variables may expose other lifestyle attributes that contribute to longevity. Along those lines, future research can also include more lifestyle and health data like exercise habits and indices of frailty to reveal other contributors to longevity.